1/*
2** 2001-09-15
3**
4** The author disclaims copyright to this source code. In place of
5** a legal notice, here is a blessing:
6**
7** May you do good and not evil.
8** May you find forgiveness for yourself and forgive others.
9** May you share freely, never taking more than you give.
10**
11*************************************************************************
12** This header file defines the interface that the SQLite library
13** presents to client programs. If a C-function, structure, datatype,
14** or constant definition does not appear in this file, then it is
15** not a published API of SQLite, is subject to change without
16** notice, and should not be referenced by programs that use SQLite.
17**
18** Some of the definitions that are in this file are marked as
19** "experimental". Experimental interfaces are normally new
20** features recently added to SQLite. We do not anticipate changes
21** to experimental interfaces but reserve the right to make minor changes
22** if experience from use "in the wild" suggest such changes are prudent.
23**
24** The official C-language API documentation for SQLite is derived
25** from comments in this file. This file is the authoritative source
26** on how SQLite interfaces are supposed to operate.
27**
28** The name of this file under configuration management is "sqlite.h.in".
29** The makefile makes some minor changes to this file (such as inserting
30** the version number) and changes its name to "sqlite3.h" as
31** part of the build process.
32*/
33#ifndef SQLITE3_H
34#define SQLITE3_H
35#include <stdarg.h> /* Needed for the definition of va_list */
36
37/*
38** Make sure we can call this stuff from C++.
39*/
40#ifdef __cplusplus
41extern "C" {
42#endif
43
44
45/*
46** Facilitate override of interface linkage and calling conventions.
47** Be aware that these macros may not be used within this particular
48** translation of the amalgamation and its associated header file.
49**
50** The SQLITE_EXTERN and SQLITE_API macros are used to instruct the
51** compiler that the target identifier should have external linkage.
52**
53** The SQLITE_CDECL macro is used to set the calling convention for
54** public functions that accept a variable number of arguments.
55**
56** The SQLITE_APICALL macro is used to set the calling convention for
57** public functions that accept a fixed number of arguments.
58**
59** The SQLITE_STDCALL macro is no longer used and is now deprecated.
60**
61** The SQLITE_CALLBACK macro is used to set the calling convention for
62** function pointers.
63**
64** The SQLITE_SYSAPI macro is used to set the calling convention for
65** functions provided by the operating system.
66**
67** Currently, the SQLITE_CDECL, SQLITE_APICALL, SQLITE_CALLBACK, and
68** SQLITE_SYSAPI macros are used only when building for environments
69** that require non-default calling conventions.
70*/
71#ifndef SQLITE_EXTERN
72# define SQLITE_EXTERN extern
73#endif
74#ifndef SQLITE_API
75# define SQLITE_API
76#endif
77#ifndef SQLITE_CDECL
78# define SQLITE_CDECL
79#endif
80#ifndef SQLITE_APICALL
81# define SQLITE_APICALL
82#endif
83#ifndef SQLITE_STDCALL
84# define SQLITE_STDCALL SQLITE_APICALL
85#endif
86#ifndef SQLITE_CALLBACK
87# define SQLITE_CALLBACK
88#endif
89#ifndef SQLITE_SYSAPI
90# define SQLITE_SYSAPI
91#endif
92
93/*
94** These no-op macros are used in front of interfaces to mark those
95** interfaces as either deprecated or experimental. New applications
96** should not use deprecated interfaces - they are supported for backwards
97** compatibility only. Application writers should be aware that
98** experimental interfaces are subject to change in point releases.
99**
100** These macros used to resolve to various kinds of compiler magic that
101** would generate warning messages when they were used. But that
102** compiler magic ended up generating such a flurry of bug reports
103** that we have taken it all out and gone back to using simple
104** noop macros.
105*/
106#define SQLITE_DEPRECATED
107#define SQLITE_EXPERIMENTAL
108
109/*
110** Ensure these symbols were not defined by some previous header file.
111*/
112#ifdef SQLITE_VERSION
113# undef SQLITE_VERSION
114#endif
115#ifdef SQLITE_VERSION_NUMBER
116# undef SQLITE_VERSION_NUMBER
117#endif
118
119/*
120** CAPI3REF: Compile-Time Library Version Numbers
121**
122** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header
123** evaluates to a string literal that is the SQLite version in the
124** format "X.Y.Z" where X is the major version number (always 3 for
125** SQLite3) and Y is the minor version number and Z is the release number.)^
126** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer
127** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same
128** numbers used in [SQLITE_VERSION].)^
129** The SQLITE_VERSION_NUMBER for any given release of SQLite will also
130** be larger than the release from which it is derived. Either Y will
131** be held constant and Z will be incremented or else Y will be incremented
132** and Z will be reset to zero.
133**
134** Since [version 3.6.18] ([dateof:3.6.18]),
135** SQLite source code has been stored in the
136** <a href="http://fossil-scm.org/">Fossil configuration management
137** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to
138** a string which identifies a particular check-in of SQLite
139** within its configuration management system. ^The SQLITE_SOURCE_ID
140** string contains the date and time of the check-in (UTC) and a SHA1
141** or SHA3-256 hash of the entire source tree. If the source code has
142** been edited in any way since it was last checked in, then the last
143** four hexadecimal digits of the hash may be modified.
144**
145** See also: [sqlite3_libversion()],
146** [sqlite3_libversion_number()], [sqlite3_sourceid()],
147** [sqlite_version()] and [sqlite_source_id()].
148*/
149#define SQLITE_VERSION "3.50.2"
150#define SQLITE_VERSION_NUMBER 3050002
151#define SQLITE_SOURCE_ID "2025-06-28 14:00:48 2af157d77fb1304a74176eaee7fbc7c7e932d946bf25325e9c26c91db19e3079"
152
153/*
154** CAPI3REF: Run-Time Library Version Numbers
155** KEYWORDS: sqlite3_version sqlite3_sourceid
156**
157** These interfaces provide the same information as the [SQLITE_VERSION],
158** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
159** but are associated with the library instead of the header file. ^(Cautious
160** programmers might include assert() statements in their application to
161** verify that values returned by these interfaces match the macros in
162** the header, and thus ensure that the application is
163** compiled with matching library and header files.
164**
165** <blockquote><pre>
166** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
167** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 );
168** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
169** </pre></blockquote>)^
170**
171** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION]
172** macro. ^The sqlite3_libversion() function returns a pointer to the
173** to the sqlite3_version[] string constant. The sqlite3_libversion()
174** function is provided for use in DLLs since DLL users usually do not have
175** direct access to string constants within the DLL. ^The
176** sqlite3_libversion_number() function returns an integer equal to
177** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns
178** a pointer to a string constant whose value is the same as the
179** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built
180** using an edited copy of [the amalgamation], then the last four characters
181** of the hash might be different from [SQLITE_SOURCE_ID].)^
182**
183** See also: [sqlite_version()] and [sqlite_source_id()].
184*/
185SQLITE_API SQLITE_EXTERN const char sqlite3_version[];
186SQLITE_API const char *sqlite3_libversion(void);
187SQLITE_API const char *sqlite3_sourceid(void);
188SQLITE_API int sqlite3_libversion_number(void);
189
190/*
191** CAPI3REF: Run-Time Library Compilation Options Diagnostics
192**
193** ^The sqlite3_compileoption_used() function returns 0 or 1
194** indicating whether the specified option was defined at
195** compile time. ^The SQLITE_ prefix may be omitted from the
196** option name passed to sqlite3_compileoption_used().
197**
198** ^The sqlite3_compileoption_get() function allows iterating
199** over the list of options that were defined at compile time by
200** returning the N-th compile time option string. ^If N is out of range,
201** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_
202** prefix is omitted from any strings returned by
203** sqlite3_compileoption_get().
204**
205** ^Support for the diagnostic functions sqlite3_compileoption_used()
206** and sqlite3_compileoption_get() may be omitted by specifying the
207** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time.
208**
209** See also: SQL functions [sqlite_compileoption_used()] and
210** [sqlite_compileoption_get()] and the [compile_options pragma].
211*/
212#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
213SQLITE_API int sqlite3_compileoption_used(const char *zOptName);
214SQLITE_API const char *sqlite3_compileoption_get(int N);
215#else
216# define sqlite3_compileoption_used(X) 0
217# define sqlite3_compileoption_get(X) ((void*)0)
218#endif
219
220/*
221** CAPI3REF: Test To See If The Library Is Threadsafe
222**
223** ^The sqlite3_threadsafe() function returns zero if and only if
224** SQLite was compiled with mutexing code omitted due to the
225** [SQLITE_THREADSAFE] compile-time option being set to 0.
226**
227** SQLite can be compiled with or without mutexes. When
228** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
229** are enabled and SQLite is threadsafe. When the
230** [SQLITE_THREADSAFE] macro is 0,
231** the mutexes are omitted. Without the mutexes, it is not safe
232** to use SQLite concurrently from more than one thread.
233**
234** Enabling mutexes incurs a measurable performance penalty.
235** So if speed is of utmost importance, it makes sense to disable
236** the mutexes. But for maximum safety, mutexes should be enabled.
237** ^The default behavior is for mutexes to be enabled.
238**
239** This interface can be used by an application to make sure that the
240** version of SQLite that it is linking against was compiled with
241** the desired setting of the [SQLITE_THREADSAFE] macro.
242**
243** This interface only reports on the compile-time mutex setting
244** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with
245** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
246** can be fully or partially disabled using a call to [sqlite3_config()]
247** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
248** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the
249** sqlite3_threadsafe() function shows only the compile-time setting of
250** thread safety, not any run-time changes to that setting made by
251** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
252** is unchanged by calls to sqlite3_config().)^
253**
254** See the [threading mode] documentation for additional information.
255*/
256SQLITE_API int sqlite3_threadsafe(void);
257
258/*
259** CAPI3REF: Database Connection Handle
260** KEYWORDS: {database connection} {database connections}
261**
262** Each open SQLite database is represented by a pointer to an instance of
263** the opaque structure named "sqlite3". It is useful to think of an sqlite3
264** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and
265** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
266** and [sqlite3_close_v2()] are its destructors. There are many other
267** interfaces (such as
268** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
269** [sqlite3_busy_timeout()] to name but three) that are methods on an
270** sqlite3 object.
271*/
272typedef struct sqlite3 sqlite3;
273
274/*
275** CAPI3REF: 64-Bit Integer Types
276** KEYWORDS: sqlite_int64 sqlite_uint64
277**
278** Because there is no cross-platform way to specify 64-bit integer types
279** SQLite includes typedefs for 64-bit signed and unsigned integers.
280**
281** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
282** The sqlite_int64 and sqlite_uint64 types are supported for backwards
283** compatibility only.
284**
285** ^The sqlite3_int64 and sqlite_int64 types can store integer values
286** between -9223372036854775808 and +9223372036854775807 inclusive. ^The
287** sqlite3_uint64 and sqlite_uint64 types can store integer values
288** between 0 and +18446744073709551615 inclusive.
289*/
290#ifdef SQLITE_INT64_TYPE
291 typedef SQLITE_INT64_TYPE sqlite_int64;
292# ifdef SQLITE_UINT64_TYPE
293 typedef SQLITE_UINT64_TYPE sqlite_uint64;
294# else
295 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
296# endif
297#elif defined(_MSC_VER) || defined(__BORLANDC__)
298 typedef __int64 sqlite_int64;
299 typedef unsigned __int64 sqlite_uint64;
300#else
301 typedef long long int sqlite_int64;
302 typedef unsigned long long int sqlite_uint64;
303#endif
304typedef sqlite_int64 sqlite3_int64;
305typedef sqlite_uint64 sqlite3_uint64;
306
307/*
308** If compiling for a processor that lacks floating point support,
309** substitute integer for floating-point.
310*/
311#ifdef SQLITE_OMIT_FLOATING_POINT
312# define double sqlite3_int64
313#endif
314
315/*
316** CAPI3REF: Closing A Database Connection
317** DESTRUCTOR: sqlite3
318**
319** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors
320** for the [sqlite3] object.
321** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if
322** the [sqlite3] object is successfully destroyed and all associated
323** resources are deallocated.
324**
325** Ideally, applications should [sqlite3_finalize | finalize] all
326** [prepared statements], [sqlite3_blob_close | close] all [BLOB handles], and
327** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated
328** with the [sqlite3] object prior to attempting to close the object.
329** ^If the database connection is associated with unfinalized prepared
330** statements, BLOB handlers, and/or unfinished sqlite3_backup objects then
331** sqlite3_close() will leave the database connection open and return
332** [SQLITE_BUSY]. ^If sqlite3_close_v2() is called with unfinalized prepared
333** statements, unclosed BLOB handlers, and/or unfinished sqlite3_backups,
334** it returns [SQLITE_OK] regardless, but instead of deallocating the database
335** connection immediately, it marks the database connection as an unusable
336** "zombie" and makes arrangements to automatically deallocate the database
337** connection after all prepared statements are finalized, all BLOB handles
338** are closed, and all backups have finished. The sqlite3_close_v2() interface
339** is intended for use with host languages that are garbage collected, and
340** where the order in which destructors are called is arbitrary.
341**
342** ^If an [sqlite3] object is destroyed while a transaction is open,
343** the transaction is automatically rolled back.
344**
345** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)]
346** must be either a NULL
347** pointer or an [sqlite3] object pointer obtained
348** from [sqlite3_open()], [sqlite3_open16()], or
349** [sqlite3_open_v2()], and not previously closed.
350** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer
351** argument is a harmless no-op.
352*/
353SQLITE_API int sqlite3_close(sqlite3*);
354SQLITE_API int sqlite3_close_v2(sqlite3*);
355
356/*
357** The type for a callback function.
358** This is legacy and deprecated. It is included for historical
359** compatibility and is not documented.
360*/
361typedef int (*sqlite3_callback)(void*,int,char**, char**);
362
363/*
364** CAPI3REF: One-Step Query Execution Interface
365** METHOD: sqlite3
366**
367** The sqlite3_exec() interface is a convenience wrapper around
368** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
369** that allows an application to run multiple statements of SQL
370** without having to use a lot of C code.
371**
372** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
373** semicolon-separate SQL statements passed into its 2nd argument,
374** in the context of the [database connection] passed in as its 1st
375** argument. ^If the callback function of the 3rd argument to
376** sqlite3_exec() is not NULL, then it is invoked for each result row
377** coming out of the evaluated SQL statements. ^The 4th argument to
378** sqlite3_exec() is relayed through to the 1st argument of each
379** callback invocation. ^If the callback pointer to sqlite3_exec()
380** is NULL, then no callback is ever invoked and result rows are
381** ignored.
382**
383** ^If an error occurs while evaluating the SQL statements passed into
384** sqlite3_exec(), then execution of the current statement stops and
385** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec()
386** is not NULL then any error message is written into memory obtained
387** from [sqlite3_malloc()] and passed back through the 5th parameter.
388** To avoid memory leaks, the application should invoke [sqlite3_free()]
389** on error message strings returned through the 5th parameter of
390** sqlite3_exec() after the error message string is no longer needed.
391** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
392** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
393** NULL before returning.
394**
395** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
396** routine returns SQLITE_ABORT without invoking the callback again and
397** without running any subsequent SQL statements.
398**
399** ^The 2nd argument to the sqlite3_exec() callback function is the
400** number of columns in the result. ^The 3rd argument to the sqlite3_exec()
401** callback is an array of pointers to strings obtained as if from
402** [sqlite3_column_text()], one for each column. ^If an element of a
403** result row is NULL then the corresponding string pointer for the
404** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the
405** sqlite3_exec() callback is an array of pointers to strings where each
406** entry represents the name of corresponding result column as obtained
407** from [sqlite3_column_name()].
408**
409** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
410** to an empty string, or a pointer that contains only whitespace and/or
411** SQL comments, then no SQL statements are evaluated and the database
412** is not changed.
413**
414** Restrictions:
415**
416** <ul>
417** <li> The application must ensure that the 1st parameter to sqlite3_exec()
418** is a valid and open [database connection].
419** <li> The application must not close the [database connection] specified by
420** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
421** <li> The application must not modify the SQL statement text passed into
422** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
423** <li> The application must not dereference the arrays or string pointers
424** passed as the 3rd and 4th callback parameters after it returns.
425** </ul>
426*/
427SQLITE_API int sqlite3_exec(
428 sqlite3*, /* An open database */
429 const char *sql, /* SQL to be evaluated */
430 int (*callback)(void*,int,char**,char**), /* Callback function */
431 void *, /* 1st argument to callback */
432 char **errmsg /* Error msg written here */
433);
434
435/*
436** CAPI3REF: Result Codes
437** KEYWORDS: {result code definitions}
438**
439** Many SQLite functions return an integer result code from the set shown
440** here in order to indicate success or failure.
441**
442** New error codes may be added in future versions of SQLite.
443**
444** See also: [extended result code definitions]
445*/
446#define SQLITE_OK 0 /* Successful result */
447/* beginning-of-error-codes */
448#define SQLITE_ERROR 1 /* Generic error */
449#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */
450#define SQLITE_PERM 3 /* Access permission denied */
451#define SQLITE_ABORT 4 /* Callback routine requested an abort */
452#define SQLITE_BUSY 5 /* The database file is locked */
453#define SQLITE_LOCKED 6 /* A table in the database is locked */
454#define SQLITE_NOMEM 7 /* A malloc() failed */
455#define SQLITE_READONLY 8 /* Attempt to write a readonly database */
456#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/
457#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */
458#define SQLITE_CORRUPT 11 /* The database disk image is malformed */
459#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */
460#define SQLITE_FULL 13 /* Insertion failed because database is full */
461#define SQLITE_CANTOPEN 14 /* Unable to open the database file */
462#define SQLITE_PROTOCOL 15 /* Database lock protocol error */
463#define SQLITE_EMPTY 16 /* Internal use only */
464#define SQLITE_SCHEMA 17 /* The database schema changed */
465#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */
466#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */
467#define SQLITE_MISMATCH 20 /* Data type mismatch */
468#define SQLITE_MISUSE 21 /* Library used incorrectly */
469#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */
470#define SQLITE_AUTH 23 /* Authorization denied */
471#define SQLITE_FORMAT 24 /* Not used */
472#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */
473#define SQLITE_NOTADB 26 /* File opened that is not a database file */
474#define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */
475#define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */
476#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */
477#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */
478/* end-of-error-codes */
479
480/*
481** CAPI3REF: Extended Result Codes
482** KEYWORDS: {extended result code definitions}
483**
484** In its default configuration, SQLite API routines return one of 30 integer
485** [result codes]. However, experience has shown that many of
486** these result codes are too coarse-grained. They do not provide as
487** much information about problems as programmers might like. In an effort to
488** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8]
489** and later) include
490** support for additional result codes that provide more detailed information
491** about errors. These [extended result codes] are enabled or disabled
492** on a per database connection basis using the
493** [sqlite3_extended_result_codes()] API. Or, the extended code for
494** the most recent error can be obtained using
495** [sqlite3_extended_errcode()].
496*/
497#define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8))
498#define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8))
499#define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8))
500#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8))
501#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8))
502#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8))
503#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8))
504#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8))
505#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8))
506#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8))
507#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8))
508#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8))
509#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8))
510#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8))
511#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8))
512#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8))
513#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))
514#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8))
515#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8))
516#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8))
517#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8))
518#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8))
519#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8))
520#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8))
521#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8))
522#define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8))
523#define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8))
524#define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8))
525#define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8))
526#define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8))
527#define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8))
528#define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8))
529#define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8))
530#define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8))
531#define SQLITE_IOERR_DATA (SQLITE_IOERR | (32<<8))
532#define SQLITE_IOERR_CORRUPTFS (SQLITE_IOERR | (33<<8))
533#define SQLITE_IOERR_IN_PAGE (SQLITE_IOERR | (34<<8))
534#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8))
535#define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8))
536#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8))
537#define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8))
538#define SQLITE_BUSY_TIMEOUT (SQLITE_BUSY | (3<<8))
539#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8))
540#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8))
541#define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8))
542#define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8))
543#define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */
544#define SQLITE_CANTOPEN_SYMLINK (SQLITE_CANTOPEN | (6<<8))
545#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8))
546#define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8))
547#define SQLITE_CORRUPT_INDEX (SQLITE_CORRUPT | (3<<8))
548#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8))
549#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8))
550#define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8))
551#define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8))
552#define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8))
553#define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8))
554#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8))
555#define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8))
556#define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8))
557#define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8))
558#define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8))
559#define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8))
560#define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8))
561#define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8))
562#define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8))
563#define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8))
564#define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8))
565#define SQLITE_CONSTRAINT_PINNED (SQLITE_CONSTRAINT |(11<<8))
566#define SQLITE_CONSTRAINT_DATATYPE (SQLITE_CONSTRAINT |(12<<8))
567#define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8))
568#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8))
569#define SQLITE_NOTICE_RBU (SQLITE_NOTICE | (3<<8))
570#define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8))
571#define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8))
572#define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8))
573#define SQLITE_OK_SYMLINK (SQLITE_OK | (2<<8)) /* internal use only */
574
575/*
576** CAPI3REF: Flags For File Open Operations
577**
578** These bit values are intended for use in the
579** 3rd parameter to the [sqlite3_open_v2()] interface and
580** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
581**
582** Only those flags marked as "Ok for sqlite3_open_v2()" may be
583** used as the third argument to the [sqlite3_open_v2()] interface.
584** The other flags have historically been ignored by sqlite3_open_v2(),
585** though future versions of SQLite might change so that an error is
586** raised if any of the disallowed bits are passed into sqlite3_open_v2().
587** Applications should not depend on the historical behavior.
588**
589** Note in particular that passing the SQLITE_OPEN_EXCLUSIVE flag into
590** [sqlite3_open_v2()] does *not* cause the underlying database file
591** to be opened using O_EXCL. Passing SQLITE_OPEN_EXCLUSIVE into
592** [sqlite3_open_v2()] has historically be a no-op and might become an
593** error in future versions of SQLite.
594*/
595#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */
596#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */
597#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */
598#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */
599#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */
600#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */
601#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */
602#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */
603#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */
604#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */
605#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */
606#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */
607#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */
608#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */
609#define SQLITE_OPEN_SUPER_JOURNAL 0x00004000 /* VFS only */
610#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */
611#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */
612#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */
613#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */
614#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */
615#define SQLITE_OPEN_NOFOLLOW 0x01000000 /* Ok for sqlite3_open_v2() */
616#define SQLITE_OPEN_EXRESCODE 0x02000000 /* Extended result codes */
617
618/* Reserved: 0x00F00000 */
619/* Legacy compatibility: */
620#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */
621
622
623/*
624** CAPI3REF: Device Characteristics
625**
626** The xDeviceCharacteristics method of the [sqlite3_io_methods]
627** object returns an integer which is a vector of these
628** bit values expressing I/O characteristics of the mass storage
629** device that holds the file that the [sqlite3_io_methods]
630** refers to.
631**
632** The SQLITE_IOCAP_ATOMIC property means that all writes of
633** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
634** mean that writes of blocks that are nnn bytes in size and
635** are aligned to an address which is an integer multiple of
636** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
637** that when data is appended to a file, the data is appended
638** first then the size of the file is extended, never the other
639** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
640** information is written to disk in the same order as calls
641** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that
642** after reboot following a crash or power loss, the only bytes in a
643** file that were written at the application level might have changed
644** and that adjacent bytes, even bytes within the same sector are
645** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN
646** flag indicates that a file cannot be deleted when open. The
647** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on
648** read-only media and cannot be changed even by processes with
649** elevated privileges.
650**
651** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying
652** filesystem supports doing multiple write operations atomically when those
653** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and
654** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE].
655**
656** The SQLITE_IOCAP_SUBPAGE_READ property means that it is ok to read
657** from the database file in amounts that are not a multiple of the
658** page size and that do not begin at a page boundary. Without this
659** property, SQLite is careful to only do full-page reads and write
660** on aligned pages, with the one exception that it will do a sub-page
661** read of the first page to access the database header.
662*/
663#define SQLITE_IOCAP_ATOMIC 0x00000001
664#define SQLITE_IOCAP_ATOMIC512 0x00000002
665#define SQLITE_IOCAP_ATOMIC1K 0x00000004
666#define SQLITE_IOCAP_ATOMIC2K 0x00000008
667#define SQLITE_IOCAP_ATOMIC4K 0x00000010
668#define SQLITE_IOCAP_ATOMIC8K 0x00000020
669#define SQLITE_IOCAP_ATOMIC16K 0x00000040
670#define SQLITE_IOCAP_ATOMIC32K 0x00000080
671#define SQLITE_IOCAP_ATOMIC64K 0x00000100
672#define SQLITE_IOCAP_SAFE_APPEND 0x00000200
673#define SQLITE_IOCAP_SEQUENTIAL 0x00000400
674#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800
675#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000
676#define SQLITE_IOCAP_IMMUTABLE 0x00002000
677#define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000
678#define SQLITE_IOCAP_SUBPAGE_READ 0x00008000
679
680/*
681** CAPI3REF: File Locking Levels
682**
683** SQLite uses one of these integer values as the second
684** argument to calls it makes to the xLock() and xUnlock() methods
685** of an [sqlite3_io_methods] object. These values are ordered from
686** lest restrictive to most restrictive.
687**
688** The argument to xLock() is always SHARED or higher. The argument to
689** xUnlock is either SHARED or NONE.
690*/
691#define SQLITE_LOCK_NONE 0 /* xUnlock() only */
692#define SQLITE_LOCK_SHARED 1 /* xLock() or xUnlock() */
693#define SQLITE_LOCK_RESERVED 2 /* xLock() only */
694#define SQLITE_LOCK_PENDING 3 /* xLock() only */
695#define SQLITE_LOCK_EXCLUSIVE 4 /* xLock() only */
696
697/*
698** CAPI3REF: Synchronization Type Flags
699**
700** When SQLite invokes the xSync() method of an
701** [sqlite3_io_methods] object it uses a combination of
702** these integer values as the second argument.
703**
704** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
705** sync operation only needs to flush data to mass storage. Inode
706** information need not be flushed. If the lower four bits of the flag
707** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.
708** If the lower four bits equal SQLITE_SYNC_FULL, that means
709** to use Mac OS X style fullsync instead of fsync().
710**
711** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags
712** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL
713** settings. The [synchronous pragma] determines when calls to the
714** xSync VFS method occur and applies uniformly across all platforms.
715** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how
716** energetic or rigorous or forceful the sync operations are and
717** only make a difference on Mac OSX for the default SQLite code.
718** (Third-party VFS implementations might also make the distinction
719** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the
720** operating systems natively supported by SQLite, only Mac OSX
721** cares about the difference.)
722*/
723#define SQLITE_SYNC_NORMAL 0x00002
724#define SQLITE_SYNC_FULL 0x00003
725#define SQLITE_SYNC_DATAONLY 0x00010
726
727/*
728** CAPI3REF: OS Interface Open File Handle
729**
730** An [sqlite3_file] object represents an open file in the
731** [sqlite3_vfs | OS interface layer]. Individual OS interface
732** implementations will
733** want to subclass this object by appending additional fields
734** for their own use. The pMethods entry is a pointer to an
735** [sqlite3_io_methods] object that defines methods for performing
736** I/O operations on the open file.
737*/
738typedef struct sqlite3_file sqlite3_file;
739struct sqlite3_file {
740 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */
741};
742
743/*
744** CAPI3REF: OS Interface File Virtual Methods Object
745**
746** Every file opened by the [sqlite3_vfs.xOpen] method populates an
747** [sqlite3_file] object (or, more commonly, a subclass of the
748** [sqlite3_file] object) with a pointer to an instance of this object.
749** This object defines the methods used to perform various operations
750** against the open file represented by the [sqlite3_file] object.
751**
752** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element
753** to a non-NULL pointer, then the sqlite3_io_methods.xClose method
754** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The
755** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen]
756** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element
757** to NULL.
758**
759** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
760** [SQLITE_SYNC_FULL]. The first choice is the normal fsync().
761** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY]
762** flag may be ORed in to indicate that only the data of the file
763** and not its inode needs to be synced.
764**
765** The integer values to xLock() and xUnlock() are one of
766** <ul>
767** <li> [SQLITE_LOCK_NONE],
768** <li> [SQLITE_LOCK_SHARED],
769** <li> [SQLITE_LOCK_RESERVED],
770** <li> [SQLITE_LOCK_PENDING], or
771** <li> [SQLITE_LOCK_EXCLUSIVE].
772** </ul>
773** xLock() upgrades the database file lock. In other words, xLock() moves the
774** database file lock in the direction NONE toward EXCLUSIVE. The argument to
775** xLock() is always one of SHARED, RESERVED, PENDING, or EXCLUSIVE, never
776** SQLITE_LOCK_NONE. If the database file lock is already at or above the
777** requested lock, then the call to xLock() is a no-op.
778** xUnlock() downgrades the database file lock to either SHARED or NONE.
779** If the lock is already at or below the requested lock state, then the call
780** to xUnlock() is a no-op.
781** The xCheckReservedLock() method checks whether any database connection,
782** either in this process or in some other process, is holding a RESERVED,
783** PENDING, or EXCLUSIVE lock on the file. It returns, via its output
784** pointer parameter, true if such a lock exists and false otherwise.
785**
786** The xFileControl() method is a generic interface that allows custom
787** VFS implementations to directly control an open file using the
788** [sqlite3_file_control()] interface. The second "op" argument is an
789** integer opcode. The third argument is a generic pointer intended to
790** point to a structure that may contain arguments or space in which to
791** write return values. Potential uses for xFileControl() might be
792** functions to enable blocking locks with timeouts, to change the
793** locking strategy (for example to use dot-file locks), to inquire
794** about the status of a lock, or to break stale locks. The SQLite
795** core reserves all opcodes less than 100 for its own use.
796** A [file control opcodes | list of opcodes] less than 100 is available.
797** Applications that define a custom xFileControl method should use opcodes
798** greater than 100 to avoid conflicts. VFS implementations should
799** return [SQLITE_NOTFOUND] for file control opcodes that they do not
800** recognize.
801**
802** The xSectorSize() method returns the sector size of the
803** device that underlies the file. The sector size is the
804** minimum write that can be performed without disturbing
805** other bytes in the file. The xDeviceCharacteristics()
806** method returns a bit vector describing behaviors of the
807** underlying device:
808**
809** <ul>
810** <li> [SQLITE_IOCAP_ATOMIC]
811** <li> [SQLITE_IOCAP_ATOMIC512]
812** <li> [SQLITE_IOCAP_ATOMIC1K]
813** <li> [SQLITE_IOCAP_ATOMIC2K]
814** <li> [SQLITE_IOCAP_ATOMIC4K]
815** <li> [SQLITE_IOCAP_ATOMIC8K]
816** <li> [SQLITE_IOCAP_ATOMIC16K]
817** <li> [SQLITE_IOCAP_ATOMIC32K]
818** <li> [SQLITE_IOCAP_ATOMIC64K]
819** <li> [SQLITE_IOCAP_SAFE_APPEND]
820** <li> [SQLITE_IOCAP_SEQUENTIAL]
821** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN]
822** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE]
823** <li> [SQLITE_IOCAP_IMMUTABLE]
824** <li> [SQLITE_IOCAP_BATCH_ATOMIC]
825** <li> [SQLITE_IOCAP_SUBPAGE_READ]
826** </ul>
827**
828** The SQLITE_IOCAP_ATOMIC property means that all writes of
829** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
830** mean that writes of blocks that are nnn bytes in size and
831** are aligned to an address which is an integer multiple of
832** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
833** that when data is appended to a file, the data is appended
834** first then the size of the file is extended, never the other
835** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
836** information is written to disk in the same order as calls
837** to xWrite().
838**
839** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
840** in the unread portions of the buffer with zeros. A VFS that
841** fails to zero-fill short reads might seem to work. However,
842** failure to zero-fill short reads will eventually lead to
843** database corruption.
844*/
845typedef struct sqlite3_io_methods sqlite3_io_methods;
846struct sqlite3_io_methods {
847 int iVersion;
848 int (*xClose)(sqlite3_file*);
849 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
850 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
851 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
852 int (*xSync)(sqlite3_file*, int flags);
853 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
854 int (*xLock)(sqlite3_file*, int);
855 int (*xUnlock)(sqlite3_file*, int);
856 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);
857 int (*xFileControl)(sqlite3_file*, int op, void *pArg);
858 int (*xSectorSize)(sqlite3_file*);
859 int (*xDeviceCharacteristics)(sqlite3_file*);
860 /* Methods above are valid for version 1 */
861 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
862 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags);
863 void (*xShmBarrier)(sqlite3_file*);
864 int (*xShmUnmap)(sqlite3_file*, int deleteFlag);
865 /* Methods above are valid for version 2 */
866 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp);
867 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p);
868 /* Methods above are valid for version 3 */
869 /* Additional methods may be added in future releases */
870};
871
872/*
873** CAPI3REF: Standard File Control Opcodes
874** KEYWORDS: {file control opcodes} {file control opcode}
875**
876** These integer constants are opcodes for the xFileControl method
877** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
878** interface.
879**
880** <ul>
881** <li>[[SQLITE_FCNTL_LOCKSTATE]]
882** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This
883** opcode causes the xFileControl method to write the current state of
884** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
885** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
886** into an integer that the pArg argument points to.
887** This capability is only available if SQLite is compiled with [SQLITE_DEBUG].
888**
889** <li>[[SQLITE_FCNTL_SIZE_HINT]]
890** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
891** layer a hint of how large the database file will grow to be during the
892** current transaction. This hint is not guaranteed to be accurate but it
893** is often close. The underlying VFS might choose to preallocate database
894** file space based on this hint in order to help writes to the database
895** file run faster.
896**
897** <li>[[SQLITE_FCNTL_SIZE_LIMIT]]
898** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that
899** implements [sqlite3_deserialize()] to set an upper bound on the size
900** of the in-memory database. The argument is a pointer to a [sqlite3_int64].
901** If the integer pointed to is negative, then it is filled in with the
902** current limit. Otherwise the limit is set to the larger of the value
903** of the integer pointed to and the current database size. The integer
904** pointed to is set to the new limit.
905**
906** <li>[[SQLITE_FCNTL_CHUNK_SIZE]]
907** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
908** extends and truncates the database file in chunks of a size specified
909** by the user. The fourth argument to [sqlite3_file_control()] should
910** point to an integer (type int) containing the new chunk-size to use
911** for the nominated database. Allocating database file space in large
912** chunks (say 1MB at a time), may reduce file-system fragmentation and
913** improve performance on some systems.
914**
915** <li>[[SQLITE_FCNTL_FILE_POINTER]]
916** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
917** to the [sqlite3_file] object associated with a particular database
918** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER].
919**
920** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]]
921** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer
922** to the [sqlite3_file] object associated with the journal file (either
923** the [rollback journal] or the [write-ahead log]) for a particular database
924** connection. See also [SQLITE_FCNTL_FILE_POINTER].
925**
926** <li>[[SQLITE_FCNTL_SYNC_OMITTED]]
927** No longer in use.
928**
929** <li>[[SQLITE_FCNTL_SYNC]]
930** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and
931** sent to the VFS immediately before the xSync method is invoked on a
932** database file descriptor. Or, if the xSync method is not invoked
933** because the user has configured SQLite with
934** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place
935** of the xSync method. In most cases, the pointer argument passed with
936** this file-control is NULL. However, if the database file is being synced
937** as part of a multi-database commit, the argument points to a nul-terminated
938** string containing the transactions super-journal file name. VFSes that
939** do not need this signal should silently ignore this opcode. Applications
940** should not call [sqlite3_file_control()] with this opcode as doing so may
941** disrupt the operation of the specialized VFSes that do require it.
942**
943** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]]
944** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite
945** and sent to the VFS after a transaction has been committed immediately
946** but before the database is unlocked. VFSes that do not need this signal
947** should silently ignore this opcode. Applications should not call
948** [sqlite3_file_control()] with this opcode as doing so may disrupt the
949** operation of the specialized VFSes that do require it.
950**
951** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]]
952** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
953** retry counts and intervals for certain disk I/O operations for the
954** windows [VFS] in order to provide robustness in the presence of
955** anti-virus programs. By default, the windows VFS will retry file read,
956** file write, and file delete operations up to 10 times, with a delay
957** of 25 milliseconds before the first retry and with the delay increasing
958** by an additional 25 milliseconds with each subsequent retry. This
959** opcode allows these two values (10 retries and 25 milliseconds of delay)
960** to be adjusted. The values are changed for all database connections
961** within the same process. The argument is a pointer to an array of two
962** integers where the first integer is the new retry count and the second
963** integer is the delay. If either integer is negative, then the setting
964** is not changed but instead the prior value of that setting is written
965** into the array entry, allowing the current retry settings to be
966** interrogated. The zDbName parameter is ignored.
967**
968** <li>[[SQLITE_FCNTL_PERSIST_WAL]]
969** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
970** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary
971** write ahead log ([WAL file]) and shared memory
972** files used for transaction control
973** are automatically deleted when the latest connection to the database
974** closes. Setting persistent WAL mode causes those files to persist after
975** close. Persisting the files is useful when other processes that do not
976** have write permission on the directory containing the database file want
977** to read the database file, as the WAL and shared memory files must exist
978** in order for the database to be readable. The fourth parameter to
979** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
980** That integer is 0 to disable persistent WAL mode or 1 to enable persistent
981** WAL mode. If the integer is -1, then it is overwritten with the current
982** WAL persistence setting.
983**
984** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]]
985** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the
986** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting
987** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the
988** xDeviceCharacteristics methods. The fourth parameter to
989** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
990** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage
991** mode. If the integer is -1, then it is overwritten with the current
992** zero-damage mode setting.
993**
994** <li>[[SQLITE_FCNTL_OVERWRITE]]
995** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
996** a write transaction to indicate that, unless it is rolled back for some
997** reason, the entire database file will be overwritten by the current
998** transaction. This is used by VACUUM operations.
999**
1000** <li>[[SQLITE_FCNTL_VFSNAME]]
1001** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of
1002** all [VFSes] in the VFS stack. The names are of all VFS shims and the
1003** final bottom-level VFS are written into memory obtained from
1004** [sqlite3_malloc()] and the result is stored in the char* variable
1005** that the fourth parameter of [sqlite3_file_control()] points to.
1006** The caller is responsible for freeing the memory when done. As with
1007** all file-control actions, there is no guarantee that this will actually
1008** do anything. Callers should initialize the char* variable to a NULL
1009** pointer in case this file-control is not implemented. This file-control
1010** is intended for diagnostic use only.
1011**
1012** <li>[[SQLITE_FCNTL_VFS_POINTER]]
1013** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level
1014** [VFSes] currently in use. ^(The argument X in
1015** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be
1016** of type "[sqlite3_vfs] **". This opcodes will set *X
1017** to a pointer to the top-level VFS.)^
1018** ^When there are multiple VFS shims in the stack, this opcode finds the
1019** upper-most shim only.
1020**
1021** <li>[[SQLITE_FCNTL_PRAGMA]]
1022** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA]
1023** file control is sent to the open [sqlite3_file] object corresponding
1024** to the database file to which the pragma statement refers. ^The argument
1025** to the [SQLITE_FCNTL_PRAGMA] file control is an array of
1026** pointers to strings (char**) in which the second element of the array
1027** is the name of the pragma and the third element is the argument to the
1028** pragma or NULL if the pragma has no argument. ^The handler for an
1029** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element
1030** of the char** argument point to a string obtained from [sqlite3_mprintf()]
1031** or the equivalent and that string will become the result of the pragma or
1032** the error message if the pragma fails. ^If the
1033** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal
1034** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA]
1035** file control returns [SQLITE_OK], then the parser assumes that the
1036** VFS has handled the PRAGMA itself and the parser generates a no-op
1037** prepared statement if result string is NULL, or that returns a copy
1038** of the result string if the string is non-NULL.
1039** ^If the [SQLITE_FCNTL_PRAGMA] file control returns
1040** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
1041** that the VFS encountered an error while handling the [PRAGMA] and the
1042** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA]
1043** file control occurs at the beginning of pragma statement analysis and so
1044** it is able to override built-in [PRAGMA] statements.
1045**
1046** <li>[[SQLITE_FCNTL_BUSYHANDLER]]
1047** ^The [SQLITE_FCNTL_BUSYHANDLER]
1048** file-control may be invoked by SQLite on the database file handle
1049** shortly after it is opened in order to provide a custom VFS with access
1050** to the connection's busy-handler callback. The argument is of type (void**)
1051** - an array of two (void *) values. The first (void *) actually points
1052** to a function of type (int (*)(void *)). In order to invoke the connection's
1053** busy-handler, this function should be invoked with the second (void *) in
1054** the array as the only argument. If it returns non-zero, then the operation
1055** should be retried. If it returns zero, the custom VFS should abandon the
1056** current operation.
1057**
1058** <li>[[SQLITE_FCNTL_TEMPFILENAME]]
1059** ^Applications can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control
1060** to have SQLite generate a
1061** temporary filename using the same algorithm that is followed to generate
1062** temporary filenames for TEMP tables and other internal uses. The
1063** argument should be a char** which will be filled with the filename
1064** written into memory obtained from [sqlite3_malloc()]. The caller should
1065** invoke [sqlite3_free()] on the result to avoid a memory leak.
1066**
1067** <li>[[SQLITE_FCNTL_MMAP_SIZE]]
1068** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the
1069** maximum number of bytes that will be used for memory-mapped I/O.
1070** The argument is a pointer to a value of type sqlite3_int64 that
1071** is an advisory maximum number of bytes in the file to memory map. The
1072** pointer is overwritten with the old value. The limit is not changed if
1073** the value originally pointed to is negative, and so the current limit
1074** can be queried by passing in a pointer to a negative number. This
1075** file-control is used internally to implement [PRAGMA mmap_size].
1076**
1077** <li>[[SQLITE_FCNTL_TRACE]]
1078** The [SQLITE_FCNTL_TRACE] file control provides advisory information
1079** to the VFS about what the higher layers of the SQLite stack are doing.
1080** This file control is used by some VFS activity tracing [shims].
1081** The argument is a zero-terminated string. Higher layers in the
1082** SQLite stack may generate instances of this file control if
1083** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled.
1084**
1085** <li>[[SQLITE_FCNTL_HAS_MOVED]]
1086** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a
1087** pointer to an integer and it writes a boolean into that integer depending
1088** on whether or not the file has been renamed, moved, or deleted since it
1089** was first opened.
1090**
1091** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]]
1092** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the
1093** underlying native file handle associated with a file handle. This file
1094** control interprets its argument as a pointer to a native file handle and
1095** writes the resulting value there.
1096**
1097** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]]
1098** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This
1099** opcode causes the xFileControl method to swap the file handle with the one
1100** pointed to by the pArg argument. This capability is used during testing
1101** and only needs to be supported when SQLITE_TEST is defined.
1102**
1103** <li>[[SQLITE_FCNTL_NULL_IO]]
1104** The [SQLITE_FCNTL_NULL_IO] opcode sets the low-level file descriptor
1105** or file handle for the [sqlite3_file] object such that it will no longer
1106** read or write to the database file.
1107**
1108** <li>[[SQLITE_FCNTL_WAL_BLOCK]]
1109** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might
1110** be advantageous to block on the next WAL lock if the lock is not immediately
1111** available. The WAL subsystem issues this signal during rare
1112** circumstances in order to fix a problem with priority inversion.
1113** Applications should <em>not</em> use this file-control.
1114**
1115** <li>[[SQLITE_FCNTL_ZIPVFS]]
1116** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other
1117** VFS should return SQLITE_NOTFOUND for this opcode.
1118**
1119** <li>[[SQLITE_FCNTL_RBU]]
1120** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by
1121** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for
1122** this opcode.
1123**
1124** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]]
1125** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then
1126** the file descriptor is placed in "batch write mode", which
1127** means all subsequent write operations will be deferred and done
1128** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems
1129** that do not support batch atomic writes will return SQLITE_NOTFOUND.
1130** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to
1131** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or
1132** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make
1133** no VFS interface calls on the same [sqlite3_file] file descriptor
1134** except for calls to the xWrite method and the xFileControl method
1135** with [SQLITE_FCNTL_SIZE_HINT].
1136**
1137** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]]
1138** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write
1139** operations since the previous successful call to
1140** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically.
1141** This file control returns [SQLITE_OK] if and only if the writes were
1142** all performed successfully and have been committed to persistent storage.
1143** ^Regardless of whether or not it is successful, this file control takes
1144** the file descriptor out of batch write mode so that all subsequent
1145** write operations are independent.
1146** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without
1147** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1148**
1149** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]]
1150** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write
1151** operations since the previous successful call to
1152** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back.
1153** ^This file control takes the file descriptor out of batch write mode
1154** so that all subsequent write operations are independent.
1155** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without
1156** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1157**
1158** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]]
1159** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode is used to configure a VFS
1160** to block for up to M milliseconds before failing when attempting to
1161** obtain a file lock using the xLock or xShmLock methods of the VFS.
1162** The parameter is a pointer to a 32-bit signed integer that contains
1163** the value that M is to be set to. Before returning, the 32-bit signed
1164** integer is overwritten with the previous value of M.
1165**
1166** <li>[[SQLITE_FCNTL_BLOCK_ON_CONNECT]]
1167** The [SQLITE_FCNTL_BLOCK_ON_CONNECT] opcode is used to configure the
1168** VFS to block when taking a SHARED lock to connect to a wal mode database.
1169** This is used to implement the functionality associated with
1170** SQLITE_SETLK_BLOCK_ON_CONNECT.
1171**
1172** <li>[[SQLITE_FCNTL_DATA_VERSION]]
1173** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to
1174** a database file. The argument is a pointer to a 32-bit unsigned integer.
1175** The "data version" for the pager is written into the pointer. The
1176** "data version" changes whenever any change occurs to the corresponding
1177** database file, either through SQL statements on the same database
1178** connection or through transactions committed by separate database
1179** connections possibly in other processes. The [sqlite3_total_changes()]
1180** interface can be used to find if any database on the connection has changed,
1181** but that interface responds to changes on TEMP as well as MAIN and does
1182** not provide a mechanism to detect changes to MAIN only. Also, the
1183** [sqlite3_total_changes()] interface responds to internal changes only and
1184** omits changes made by other database connections. The
1185** [PRAGMA data_version] command provides a mechanism to detect changes to
1186** a single attached database that occur due to other database connections,
1187** but omits changes implemented by the database connection on which it is
1188** called. This file control is the only mechanism to detect changes that
1189** happen either internally or externally and that are associated with
1190** a particular attached database.
1191**
1192** <li>[[SQLITE_FCNTL_CKPT_START]]
1193** The [SQLITE_FCNTL_CKPT_START] opcode is invoked from within a checkpoint
1194** in wal mode before the client starts to copy pages from the wal
1195** file to the database file.
1196**
1197** <li>[[SQLITE_FCNTL_CKPT_DONE]]
1198** The [SQLITE_FCNTL_CKPT_DONE] opcode is invoked from within a checkpoint
1199** in wal mode after the client has finished copying pages from the wal
1200** file to the database file, but before the *-shm file is updated to
1201** record the fact that the pages have been checkpointed.
1202**
1203** <li>[[SQLITE_FCNTL_EXTERNAL_READER]]
1204** The EXPERIMENTAL [SQLITE_FCNTL_EXTERNAL_READER] opcode is used to detect
1205** whether or not there is a database client in another process with a wal-mode
1206** transaction open on the database or not. It is only available on unix.The
1207** (void*) argument passed with this file-control should be a pointer to a
1208** value of type (int). The integer value is set to 1 if the database is a wal
1209** mode database and there exists at least one client in another process that
1210** currently has an SQL transaction open on the database. It is set to 0 if
1211** the database is not a wal-mode db, or if there is no such connection in any
1212** other process. This opcode cannot be used to detect transactions opened
1213** by clients within the current process, only within other processes.
1214**
1215** <li>[[SQLITE_FCNTL_CKSM_FILE]]
1216** The [SQLITE_FCNTL_CKSM_FILE] opcode is for use internally by the
1217** [checksum VFS shim] only.
1218**
1219** <li>[[SQLITE_FCNTL_RESET_CACHE]]
1220** If there is currently no transaction open on the database, and the
1221** database is not a temp db, then the [SQLITE_FCNTL_RESET_CACHE] file-control
1222** purges the contents of the in-memory page cache. If there is an open
1223** transaction, or if the db is a temp-db, this opcode is a no-op, not an error.
1224** </ul>
1225*/
1226#define SQLITE_FCNTL_LOCKSTATE 1
1227#define SQLITE_FCNTL_GET_LOCKPROXYFILE 2
1228#define SQLITE_FCNTL_SET_LOCKPROXYFILE 3
1229#define SQLITE_FCNTL_LAST_ERRNO 4
1230#define SQLITE_FCNTL_SIZE_HINT 5
1231#define SQLITE_FCNTL_CHUNK_SIZE 6
1232#define SQLITE_FCNTL_FILE_POINTER 7
1233#define SQLITE_FCNTL_SYNC_OMITTED 8
1234#define SQLITE_FCNTL_WIN32_AV_RETRY 9
1235#define SQLITE_FCNTL_PERSIST_WAL 10
1236#define SQLITE_FCNTL_OVERWRITE 11
1237#define SQLITE_FCNTL_VFSNAME 12
1238#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13
1239#define SQLITE_FCNTL_PRAGMA 14
1240#define SQLITE_FCNTL_BUSYHANDLER 15
1241#define SQLITE_FCNTL_TEMPFILENAME 16
1242#define SQLITE_FCNTL_MMAP_SIZE 18
1243#define SQLITE_FCNTL_TRACE 19
1244#define SQLITE_FCNTL_HAS_MOVED 20
1245#define SQLITE_FCNTL_SYNC 21
1246#define SQLITE_FCNTL_COMMIT_PHASETWO 22
1247#define SQLITE_FCNTL_WIN32_SET_HANDLE 23
1248#define SQLITE_FCNTL_WAL_BLOCK 24
1249#define SQLITE_FCNTL_ZIPVFS 25
1250#define SQLITE_FCNTL_RBU 26
1251#define SQLITE_FCNTL_VFS_POINTER 27
1252#define SQLITE_FCNTL_JOURNAL_POINTER 28
1253#define SQLITE_FCNTL_WIN32_GET_HANDLE 29
1254#define SQLITE_FCNTL_PDB 30
1255#define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31
1256#define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32
1257#define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33
1258#define SQLITE_FCNTL_LOCK_TIMEOUT 34
1259#define SQLITE_FCNTL_DATA_VERSION 35
1260#define SQLITE_FCNTL_SIZE_LIMIT 36
1261#define SQLITE_FCNTL_CKPT_DONE 37
1262#define SQLITE_FCNTL_RESERVE_BYTES 38
1263#define SQLITE_FCNTL_CKPT_START 39
1264#define SQLITE_FCNTL_EXTERNAL_READER 40
1265#define SQLITE_FCNTL_CKSM_FILE 41
1266#define SQLITE_FCNTL_RESET_CACHE 42
1267#define SQLITE_FCNTL_NULL_IO 43
1268#define SQLITE_FCNTL_BLOCK_ON_CONNECT 44
1269
1270/* deprecated names */
1271#define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE
1272#define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE
1273#define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO
1274
1275
1276/*
1277** CAPI3REF: Mutex Handle
1278**
1279** The mutex module within SQLite defines [sqlite3_mutex] to be an
1280** abstract type for a mutex object. The SQLite core never looks
1281** at the internal representation of an [sqlite3_mutex]. It only
1282** deals with pointers to the [sqlite3_mutex] object.
1283**
1284** Mutexes are created using [sqlite3_mutex_alloc()].
1285*/
1286typedef struct sqlite3_mutex sqlite3_mutex;
1287
1288/*
1289** CAPI3REF: Loadable Extension Thunk
1290**
1291** A pointer to the opaque sqlite3_api_routines structure is passed as
1292** the third parameter to entry points of [loadable extensions]. This
1293** structure must be typedefed in order to work around compiler warnings
1294** on some platforms.
1295*/
1296typedef struct sqlite3_api_routines sqlite3_api_routines;
1297
1298/*
1299** CAPI3REF: File Name
1300**
1301** Type [sqlite3_filename] is used by SQLite to pass filenames to the
1302** xOpen method of a [VFS]. It may be cast to (const char*) and treated
1303** as a normal, nul-terminated, UTF-8 buffer containing the filename, but
1304** may also be passed to special APIs such as:
1305**
1306** <ul>
1307** <li> sqlite3_filename_database()
1308** <li> sqlite3_filename_journal()
1309** <li> sqlite3_filename_wal()
1310** <li> sqlite3_uri_parameter()
1311** <li> sqlite3_uri_boolean()
1312** <li> sqlite3_uri_int64()
1313** <li> sqlite3_uri_key()
1314** </ul>
1315*/
1316typedef const char *sqlite3_filename;
1317
1318/*
1319** CAPI3REF: OS Interface Object
1320**
1321** An instance of the sqlite3_vfs object defines the interface between
1322** the SQLite core and the underlying operating system. The "vfs"
1323** in the name of the object stands for "virtual file system". See
1324** the [VFS | VFS documentation] for further information.
1325**
1326** The VFS interface is sometimes extended by adding new methods onto
1327** the end. Each time such an extension occurs, the iVersion field
1328** is incremented. The iVersion value started out as 1 in
1329** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2
1330** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased
1331** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields
1332** may be appended to the sqlite3_vfs object and the iVersion value
1333** may increase again in future versions of SQLite.
1334** Note that due to an oversight, the structure
1335** of the sqlite3_vfs object changed in the transition from
1336** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0]
1337** and yet the iVersion field was not increased.
1338**
1339** The szOsFile field is the size of the subclassed [sqlite3_file]
1340** structure used by this VFS. mxPathname is the maximum length of
1341** a pathname in this VFS.
1342**
1343** Registered sqlite3_vfs objects are kept on a linked list formed by
1344** the pNext pointer. The [sqlite3_vfs_register()]
1345** and [sqlite3_vfs_unregister()] interfaces manage this list
1346** in a thread-safe way. The [sqlite3_vfs_find()] interface
1347** searches the list. Neither the application code nor the VFS
1348** implementation should use the pNext pointer.
1349**
1350** The pNext field is the only field in the sqlite3_vfs
1351** structure that SQLite will ever modify. SQLite will only access
1352** or modify this field while holding a particular static mutex.
1353** The application should never modify anything within the sqlite3_vfs
1354** object once the object has been registered.
1355**
1356** The zName field holds the name of the VFS module. The name must
1357** be unique across all VFS modules.
1358**
1359** [[sqlite3_vfs.xOpen]]
1360** ^SQLite guarantees that the zFilename parameter to xOpen
1361** is either a NULL pointer or string obtained
1362** from xFullPathname() with an optional suffix added.
1363** ^If a suffix is added to the zFilename parameter, it will
1364** consist of a single "-" character followed by no more than
1365** 11 alphanumeric and/or "-" characters.
1366** ^SQLite further guarantees that
1367** the string will be valid and unchanged until xClose() is
1368** called. Because of the previous sentence,
1369** the [sqlite3_file] can safely store a pointer to the
1370** filename if it needs to remember the filename for some reason.
1371** If the zFilename parameter to xOpen is a NULL pointer then xOpen
1372** must invent its own temporary name for the file. ^Whenever the
1373** xFilename parameter is NULL it will also be the case that the
1374** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
1375**
1376** The flags argument to xOpen() includes all bits set in
1377** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()]
1378** or [sqlite3_open16()] is used, then flags includes at least
1379** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE].
1380** If xOpen() opens a file read-only then it sets *pOutFlags to
1381** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set.
1382**
1383** ^(SQLite will also add one of the following flags to the xOpen()
1384** call, depending on the object being opened:
1385**
1386** <ul>
1387** <li> [SQLITE_OPEN_MAIN_DB]
1388** <li> [SQLITE_OPEN_MAIN_JOURNAL]
1389** <li> [SQLITE_OPEN_TEMP_DB]
1390** <li> [SQLITE_OPEN_TEMP_JOURNAL]
1391** <li> [SQLITE_OPEN_TRANSIENT_DB]
1392** <li> [SQLITE_OPEN_SUBJOURNAL]
1393** <li> [SQLITE_OPEN_SUPER_JOURNAL]
1394** <li> [SQLITE_OPEN_WAL]
1395** </ul>)^
1396**
1397** The file I/O implementation can use the object type flags to
1398** change the way it deals with files. For example, an application
1399** that does not care about crash recovery or rollback might make
1400** the open of a journal file a no-op. Writes to this journal would
1401** also be no-ops, and any attempt to read the journal would return
1402** SQLITE_IOERR. Or the implementation might recognize that a database
1403** file will be doing page-aligned sector reads and writes in a random
1404** order and set up its I/O subsystem accordingly.
1405**
1406** SQLite might also add one of the following flags to the xOpen method:
1407**
1408** <ul>
1409** <li> [SQLITE_OPEN_DELETEONCLOSE]
1410** <li> [SQLITE_OPEN_EXCLUSIVE]
1411** </ul>
1412**
1413** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
1414** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE]
1415** will be set for TEMP databases and their journals, transient
1416** databases, and subjournals.
1417**
1418** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
1419** with the [SQLITE_OPEN_CREATE] flag, which are both directly
1420** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
1421** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the
1422** SQLITE_OPEN_CREATE, is used to indicate that file should always
1423** be created, and that it is an error if it already exists.
1424** It is <i>not</i> used to indicate the file should be opened
1425** for exclusive access.
1426**
1427** ^At least szOsFile bytes of memory are allocated by SQLite
1428** to hold the [sqlite3_file] structure passed as the third
1429** argument to xOpen. The xOpen method does not have to
1430** allocate the structure; it should just fill it in. Note that
1431** the xOpen method must set the sqlite3_file.pMethods to either
1432** a valid [sqlite3_io_methods] object or to NULL. xOpen must do
1433** this even if the open fails. SQLite expects that the sqlite3_file.pMethods
1434** element will be valid after xOpen returns regardless of the success
1435** or failure of the xOpen call.
1436**
1437** [[sqlite3_vfs.xAccess]]
1438** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
1439** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
1440** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
1441** to test whether a file is at least readable. The SQLITE_ACCESS_READ
1442** flag is never actually used and is not implemented in the built-in
1443** VFSes of SQLite. The file is named by the second argument and can be a
1444** directory. The xAccess method returns [SQLITE_OK] on success or some
1445** non-zero error code if there is an I/O error or if the name of
1446** the file given in the second argument is illegal. If SQLITE_OK
1447** is returned, then non-zero or zero is written into *pResOut to indicate
1448** whether or not the file is accessible.
1449**
1450** ^SQLite will always allocate at least mxPathname+1 bytes for the
1451** output buffer xFullPathname. The exact size of the output buffer
1452** is also passed as a parameter to both methods. If the output buffer
1453** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
1454** handled as a fatal error by SQLite, vfs implementations should endeavor
1455** to prevent this by setting mxPathname to a sufficiently large value.
1456**
1457** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
1458** interfaces are not strictly a part of the filesystem, but they are
1459** included in the VFS structure for completeness.
1460** The xRandomness() function attempts to return nBytes bytes
1461** of good-quality randomness into zOut. The return value is
1462** the actual number of bytes of randomness obtained.
1463** The xSleep() method causes the calling thread to sleep for at
1464** least the number of microseconds given. ^The xCurrentTime()
1465** method returns a Julian Day Number for the current date and time as
1466** a floating point value.
1467** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
1468** Day Number multiplied by 86400000 (the number of milliseconds in
1469** a 24-hour day).
1470** ^SQLite will use the xCurrentTimeInt64() method to get the current
1471** date and time if that method is available (if iVersion is 2 or
1472** greater and the function pointer is not NULL) and will fall back
1473** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
1474**
1475** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces
1476** are not used by the SQLite core. These optional interfaces are provided
1477** by some VFSes to facilitate testing of the VFS code. By overriding
1478** system calls with functions under its control, a test program can
1479** simulate faults and error conditions that would otherwise be difficult
1480** or impossible to induce. The set of system calls that can be overridden
1481** varies from one VFS to another, and from one version of the same VFS to the
1482** next. Applications that use these interfaces must be prepared for any
1483** or all of these interfaces to be NULL or for their behavior to change
1484** from one release to the next. Applications must not attempt to access
1485** any of these methods if the iVersion of the VFS is less than 3.
1486*/
1487typedef struct sqlite3_vfs sqlite3_vfs;
1488typedef void (*sqlite3_syscall_ptr)(void);
1489struct sqlite3_vfs {
1490 int iVersion; /* Structure version number (currently 3) */
1491 int szOsFile; /* Size of subclassed sqlite3_file */
1492 int mxPathname; /* Maximum file pathname length */
1493 sqlite3_vfs *pNext; /* Next registered VFS */
1494 const char *zName; /* Name of this virtual file system */
1495 void *pAppData; /* Pointer to application-specific data */
1496 int (*xOpen)(sqlite3_vfs*, sqlite3_filename zName, sqlite3_file*,
1497 int flags, int *pOutFlags);
1498 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
1499 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);
1500 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
1501 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
1502 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
1503 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);
1504 void (*xDlClose)(sqlite3_vfs*, void*);
1505 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
1506 int (*xSleep)(sqlite3_vfs*, int microseconds);
1507 int (*xCurrentTime)(sqlite3_vfs*, double*);
1508 int (*xGetLastError)(sqlite3_vfs*, int, char *);
1509 /*
1510 ** The methods above are in version 1 of the sqlite_vfs object
1511 ** definition. Those that follow are added in version 2 or later
1512 */
1513 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
1514 /*
1515 ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
1516 ** Those below are for version 3 and greater.
1517 */
1518 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr);
1519 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName);
1520 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);
1521 /*
1522 ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
1523 ** New fields may be appended in future versions. The iVersion
1524 ** value will increment whenever this happens.
1525 */
1526};
1527
1528/*
1529** CAPI3REF: Flags for the xAccess VFS method
1530**
1531** These integer constants can be used as the third parameter to
1532** the xAccess method of an [sqlite3_vfs] object. They determine
1533** what kind of permissions the xAccess method is looking for.
1534** With SQLITE_ACCESS_EXISTS, the xAccess method
1535** simply checks whether the file exists.
1536** With SQLITE_ACCESS_READWRITE, the xAccess method
1537** checks whether the named directory is both readable and writable
1538** (in other words, if files can be added, removed, and renamed within
1539** the directory).
1540** The SQLITE_ACCESS_READWRITE constant is currently used only by the
1541** [temp_store_directory pragma], though this could change in a future
1542** release of SQLite.
1543** With SQLITE_ACCESS_READ, the xAccess method
1544** checks whether the file is readable. The SQLITE_ACCESS_READ constant is
1545** currently unused, though it might be used in a future release of
1546** SQLite.
1547*/
1548#define SQLITE_ACCESS_EXISTS 0
1549#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */
1550#define SQLITE_ACCESS_READ 2 /* Unused */
1551
1552/*
1553** CAPI3REF: Flags for the xShmLock VFS method
1554**
1555** These integer constants define the various locking operations
1556** allowed by the xShmLock method of [sqlite3_io_methods]. The
1557** following are the only legal combinations of flags to the
1558** xShmLock method:
1559**
1560** <ul>
1561** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED
1562** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE
1563** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED
1564** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE
1565** </ul>
1566**
1567** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
1568** was given on the corresponding lock.
1569**
1570** The xShmLock method can transition between unlocked and SHARED or
1571** between unlocked and EXCLUSIVE. It cannot transition between SHARED
1572** and EXCLUSIVE.
1573*/
1574#define SQLITE_SHM_UNLOCK 1
1575#define SQLITE_SHM_LOCK 2
1576#define SQLITE_SHM_SHARED 4
1577#define SQLITE_SHM_EXCLUSIVE 8
1578
1579/*
1580** CAPI3REF: Maximum xShmLock index
1581**
1582** The xShmLock method on [sqlite3_io_methods] may use values
1583** between 0 and this upper bound as its "offset" argument.
1584** The SQLite core will never attempt to acquire or release a
1585** lock outside of this range
1586*/
1587#define SQLITE_SHM_NLOCK 8
1588
1589
1590/*
1591** CAPI3REF: Initialize The SQLite Library
1592**
1593** ^The sqlite3_initialize() routine initializes the
1594** SQLite library. ^The sqlite3_shutdown() routine
1595** deallocates any resources that were allocated by sqlite3_initialize().
1596** These routines are designed to aid in process initialization and
1597** shutdown on embedded systems. Workstation applications using
1598** SQLite normally do not need to invoke either of these routines.
1599**
1600** A call to sqlite3_initialize() is an "effective" call if it is
1601** the first time sqlite3_initialize() is invoked during the lifetime of
1602** the process, or if it is the first time sqlite3_initialize() is invoked
1603** following a call to sqlite3_shutdown(). ^(Only an effective call
1604** of sqlite3_initialize() does any initialization. All other calls
1605** are harmless no-ops.)^
1606**
1607** A call to sqlite3_shutdown() is an "effective" call if it is the first
1608** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only
1609** an effective call to sqlite3_shutdown() does any deinitialization.
1610** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
1611**
1612** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
1613** is not. The sqlite3_shutdown() interface must only be called from a
1614** single thread. All open [database connections] must be closed and all
1615** other SQLite resources must be deallocated prior to invoking
1616** sqlite3_shutdown().
1617**
1618** Among other things, ^sqlite3_initialize() will invoke
1619** sqlite3_os_init(). Similarly, ^sqlite3_shutdown()
1620** will invoke sqlite3_os_end().
1621**
1622** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
1623** ^If for some reason, sqlite3_initialize() is unable to initialize
1624** the library (perhaps it is unable to allocate a needed resource such
1625** as a mutex) it returns an [error code] other than [SQLITE_OK].
1626**
1627** ^The sqlite3_initialize() routine is called internally by many other
1628** SQLite interfaces so that an application usually does not need to
1629** invoke sqlite3_initialize() directly. For example, [sqlite3_open()]
1630** calls sqlite3_initialize() so the SQLite library will be automatically
1631** initialized when [sqlite3_open()] is called if it has not be initialized
1632** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
1633** compile-time option, then the automatic calls to sqlite3_initialize()
1634** are omitted and the application must call sqlite3_initialize() directly
1635** prior to using any other SQLite interface. For maximum portability,
1636** it is recommended that applications always invoke sqlite3_initialize()
1637** directly prior to using any other SQLite interface. Future releases
1638** of SQLite may require this. In other words, the behavior exhibited
1639** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
1640** default behavior in some future release of SQLite.
1641**
1642** The sqlite3_os_init() routine does operating-system specific
1643** initialization of the SQLite library. The sqlite3_os_end()
1644** routine undoes the effect of sqlite3_os_init(). Typical tasks
1645** performed by these routines include allocation or deallocation
1646** of static resources, initialization of global variables,
1647** setting up a default [sqlite3_vfs] module, or setting up
1648** a default configuration using [sqlite3_config()].
1649**
1650** The application should never invoke either sqlite3_os_init()
1651** or sqlite3_os_end() directly. The application should only invoke
1652** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init()
1653** interface is called automatically by sqlite3_initialize() and
1654** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate
1655** implementations for sqlite3_os_init() and sqlite3_os_end()
1656** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
1657** When [custom builds | built for other platforms]
1658** (using the [SQLITE_OS_OTHER=1] compile-time
1659** option) the application must supply a suitable implementation for
1660** sqlite3_os_init() and sqlite3_os_end(). An application-supplied
1661** implementation of sqlite3_os_init() or sqlite3_os_end()
1662** must return [SQLITE_OK] on success and some other [error code] upon
1663** failure.
1664*/
1665SQLITE_API int sqlite3_initialize(void);
1666SQLITE_API int sqlite3_shutdown(void);
1667SQLITE_API int sqlite3_os_init(void);
1668SQLITE_API int sqlite3_os_end(void);
1669
1670/*
1671** CAPI3REF: Configuring The SQLite Library
1672**
1673** The sqlite3_config() interface is used to make global configuration
1674** changes to SQLite in order to tune SQLite to the specific needs of
1675** the application. The default configuration is recommended for most
1676** applications and so this routine is usually not necessary. It is
1677** provided to support rare applications with unusual needs.
1678**
1679** <b>The sqlite3_config() interface is not threadsafe. The application
1680** must ensure that no other SQLite interfaces are invoked by other
1681** threads while sqlite3_config() is running.</b>
1682**
1683** The first argument to sqlite3_config() is an integer
1684** [configuration option] that determines
1685** what property of SQLite is to be configured. Subsequent arguments
1686** vary depending on the [configuration option]
1687** in the first argument.
1688**
1689** For most configuration options, the sqlite3_config() interface
1690** may only be invoked prior to library initialization using
1691** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
1692** The exceptional configuration options that may be invoked at any time
1693** are called "anytime configuration options".
1694** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
1695** [sqlite3_shutdown()] with a first argument that is not an anytime
1696** configuration option, then the sqlite3_config() call will return SQLITE_MISUSE.
1697** Note, however, that ^sqlite3_config() can be called as part of the
1698** implementation of an application-defined [sqlite3_os_init()].
1699**
1700** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
1701** ^If the option is unknown or SQLite is unable to set the option
1702** then this routine returns a non-zero [error code].
1703*/
1704SQLITE_API int sqlite3_config(int, ...);
1705
1706/*
1707** CAPI3REF: Configure database connections
1708** METHOD: sqlite3
1709**
1710** The sqlite3_db_config() interface is used to make configuration
1711** changes to a [database connection]. The interface is similar to
1712** [sqlite3_config()] except that the changes apply to a single
1713** [database connection] (specified in the first argument).
1714**
1715** The second argument to sqlite3_db_config(D,V,...) is the
1716** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code
1717** that indicates what aspect of the [database connection] is being configured.
1718** Subsequent arguments vary depending on the configuration verb.
1719**
1720** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
1721** the call is considered successful.
1722*/
1723SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...);
1724
1725/*
1726** CAPI3REF: Memory Allocation Routines
1727**
1728** An instance of this object defines the interface between SQLite
1729** and low-level memory allocation routines.
1730**
1731** This object is used in only one place in the SQLite interface.
1732** A pointer to an instance of this object is the argument to
1733** [sqlite3_config()] when the configuration option is
1734** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].
1735** By creating an instance of this object
1736** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
1737** during configuration, an application can specify an alternative
1738** memory allocation subsystem for SQLite to use for all of its
1739** dynamic memory needs.
1740**
1741** Note that SQLite comes with several [built-in memory allocators]
1742** that are perfectly adequate for the overwhelming majority of applications
1743** and that this object is only useful to a tiny minority of applications
1744** with specialized memory allocation requirements. This object is
1745** also used during testing of SQLite in order to specify an alternative
1746** memory allocator that simulates memory out-of-memory conditions in
1747** order to verify that SQLite recovers gracefully from such
1748** conditions.
1749**
1750** The xMalloc, xRealloc, and xFree methods must work like the
1751** malloc(), realloc() and free() functions from the standard C library.
1752** ^SQLite guarantees that the second argument to
1753** xRealloc is always a value returned by a prior call to xRoundup.
1754**
1755** xSize should return the allocated size of a memory allocation
1756** previously obtained from xMalloc or xRealloc. The allocated size
1757** is always at least as big as the requested size but may be larger.
1758**
1759** The xRoundup method returns what would be the allocated size of
1760** a memory allocation given a particular requested size. Most memory
1761** allocators round up memory allocations at least to the next multiple
1762** of 8. Some allocators round up to a larger multiple or to a power of 2.
1763** Every memory allocation request coming in through [sqlite3_malloc()]
1764** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0,
1765** that causes the corresponding memory allocation to fail.
1766**
1767** The xInit method initializes the memory allocator. For example,
1768** it might allocate any required mutexes or initialize internal data
1769** structures. The xShutdown method is invoked (indirectly) by
1770** [sqlite3_shutdown()] and should deallocate any resources acquired
1771** by xInit. The pAppData pointer is used as the only parameter to
1772** xInit and xShutdown.
1773**
1774** SQLite holds the [SQLITE_MUTEX_STATIC_MAIN] mutex when it invokes
1775** the xInit method, so the xInit method need not be threadsafe. The
1776** xShutdown method is only called from [sqlite3_shutdown()] so it does
1777** not need to be threadsafe either. For all other methods, SQLite
1778** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
1779** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
1780** it is by default) and so the methods are automatically serialized.
1781** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
1782** methods must be threadsafe or else make their own arrangements for
1783** serialization.
1784**
1785** SQLite will never invoke xInit() more than once without an intervening
1786** call to xShutdown().
1787*/
1788typedef struct sqlite3_mem_methods sqlite3_mem_methods;
1789struct sqlite3_mem_methods {
1790 void *(*xMalloc)(int); /* Memory allocation function */
1791 void (*xFree)(void*); /* Free a prior allocation */
1792 void *(*xRealloc)(void*,int); /* Resize an allocation */
1793 int (*xSize)(void*); /* Return the size of an allocation */
1794 int (*xRoundup)(int); /* Round up request size to allocation size */
1795 int (*xInit)(void*); /* Initialize the memory allocator */
1796 void (*xShutdown)(void*); /* Deinitialize the memory allocator */
1797 void *pAppData; /* Argument to xInit() and xShutdown() */
1798};
1799
1800/*
1801** CAPI3REF: Configuration Options
1802** KEYWORDS: {configuration option}
1803**
1804** These constants are the available integer configuration options that
1805** can be passed as the first argument to the [sqlite3_config()] interface.
1806**
1807** Most of the configuration options for sqlite3_config()
1808** will only work if invoked prior to [sqlite3_initialize()] or after
1809** [sqlite3_shutdown()]. The few exceptions to this rule are called
1810** "anytime configuration options".
1811** ^Calling [sqlite3_config()] with a first argument that is not an
1812** anytime configuration option in between calls to [sqlite3_initialize()] and
1813** [sqlite3_shutdown()] is a no-op that returns SQLITE_MISUSE.
1814**
1815** The set of anytime configuration options can change (by insertions
1816** and/or deletions) from one release of SQLite to the next.
1817** As of SQLite version 3.42.0, the complete set of anytime configuration
1818** options is:
1819** <ul>
1820** <li> SQLITE_CONFIG_LOG
1821** <li> SQLITE_CONFIG_PCACHE_HDRSZ
1822** </ul>
1823**
1824** New configuration options may be added in future releases of SQLite.
1825** Existing configuration options might be discontinued. Applications
1826** should check the return code from [sqlite3_config()] to make sure that
1827** the call worked. The [sqlite3_config()] interface will return a
1828** non-zero [error code] if a discontinued or unsupported configuration option
1829** is invoked.
1830**
1831** <dl>
1832** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
1833** <dd>There are no arguments to this option. ^This option sets the
1834** [threading mode] to Single-thread. In other words, it disables
1835** all mutexing and puts SQLite into a mode where it can only be used
1836** by a single thread. ^If SQLite is compiled with
1837** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1838** it is not possible to change the [threading mode] from its default
1839** value of Single-thread and so [sqlite3_config()] will return
1840** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
1841** configuration option.</dd>
1842**
1843** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt>
1844** <dd>There are no arguments to this option. ^This option sets the
1845** [threading mode] to Multi-thread. In other words, it disables
1846** mutexing on [database connection] and [prepared statement] objects.
1847** The application is responsible for serializing access to
1848** [database connections] and [prepared statements]. But other mutexes
1849** are enabled so that SQLite will be safe to use in a multi-threaded
1850** environment as long as no two threads attempt to use the same
1851** [database connection] at the same time. ^If SQLite is compiled with
1852** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1853** it is not possible to set the Multi-thread [threading mode] and
1854** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1855** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
1856**
1857** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt>
1858** <dd>There are no arguments to this option. ^This option sets the
1859** [threading mode] to Serialized. In other words, this option enables
1860** all mutexes including the recursive
1861** mutexes on [database connection] and [prepared statement] objects.
1862** In this mode (which is the default when SQLite is compiled with
1863** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
1864** to [database connections] and [prepared statements] so that the
1865** application is free to use the same [database connection] or the
1866** same [prepared statement] in different threads at the same time.
1867** ^If SQLite is compiled with
1868** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1869** it is not possible to set the Serialized [threading mode] and
1870** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1871** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
1872**
1873** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
1874** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is
1875** a pointer to an instance of the [sqlite3_mem_methods] structure.
1876** The argument specifies
1877** alternative low-level memory allocation routines to be used in place of
1878** the memory allocation routines built into SQLite.)^ ^SQLite makes
1879** its own private copy of the content of the [sqlite3_mem_methods] structure
1880** before the [sqlite3_config()] call returns.</dd>
1881**
1882** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
1883** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which
1884** is a pointer to an instance of the [sqlite3_mem_methods] structure.
1885** The [sqlite3_mem_methods]
1886** structure is filled with the currently defined memory allocation routines.)^
1887** This option can be used to overload the default memory allocation
1888** routines with a wrapper that simulations memory allocation failure or
1889** tracks memory usage, for example. </dd>
1890**
1891** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt>
1892** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of
1893** type int, interpreted as a boolean, which if true provides a hint to
1894** SQLite that it should avoid large memory allocations if possible.
1895** SQLite will run faster if it is free to make large memory allocations,
1896** but some application might prefer to run slower in exchange for
1897** guarantees about memory fragmentation that are possible if large
1898** allocations are avoided. This hint is normally off.
1899** </dd>
1900**
1901** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
1902** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int,
1903** interpreted as a boolean, which enables or disables the collection of
1904** memory allocation statistics. ^(When memory allocation statistics are
1905** disabled, the following SQLite interfaces become non-operational:
1906** <ul>
1907** <li> [sqlite3_hard_heap_limit64()]
1908** <li> [sqlite3_memory_used()]
1909** <li> [sqlite3_memory_highwater()]
1910** <li> [sqlite3_soft_heap_limit64()]
1911** <li> [sqlite3_status64()]
1912** </ul>)^
1913** ^Memory allocation statistics are enabled by default unless SQLite is
1914** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
1915** allocation statistics are disabled by default.
1916** </dd>
1917**
1918** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
1919** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used.
1920** </dd>
1921**
1922** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
1923** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool
1924** that SQLite can use for the database page cache with the default page
1925** cache implementation.
1926** This configuration option is a no-op if an application-defined page
1927** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2].
1928** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to
1929** 8-byte aligned memory (pMem), the size of each page cache line (sz),
1930** and the number of cache lines (N).
1931** The sz argument should be the size of the largest database page
1932** (a power of two between 512 and 65536) plus some extra bytes for each
1933** page header. ^The number of extra bytes needed by the page header
1934** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ].
1935** ^It is harmless, apart from the wasted memory,
1936** for the sz parameter to be larger than necessary. The pMem
1937** argument must be either a NULL pointer or a pointer to an 8-byte
1938** aligned block of memory of at least sz*N bytes, otherwise
1939** subsequent behavior is undefined.
1940** ^When pMem is not NULL, SQLite will strive to use the memory provided
1941** to satisfy page cache needs, falling back to [sqlite3_malloc()] if
1942** a page cache line is larger than sz bytes or if all of the pMem buffer
1943** is exhausted.
1944** ^If pMem is NULL and N is non-zero, then each database connection
1945** does an initial bulk allocation for page cache memory
1946** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or
1947** of -1024*N bytes if N is negative, . ^If additional
1948** page cache memory is needed beyond what is provided by the initial
1949** allocation, then SQLite goes to [sqlite3_malloc()] separately for each
1950** additional cache line. </dd>
1951**
1952** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
1953** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer
1954** that SQLite will use for all of its dynamic memory allocation needs
1955** beyond those provided for by [SQLITE_CONFIG_PAGECACHE].
1956** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled
1957** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns
1958** [SQLITE_ERROR] if invoked otherwise.
1959** ^There are three arguments to SQLITE_CONFIG_HEAP:
1960** An 8-byte aligned pointer to the memory,
1961** the number of bytes in the memory buffer, and the minimum allocation size.
1962** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
1963** to using its default memory allocator (the system malloc() implementation),
1964** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the
1965** memory pointer is not NULL then the alternative memory
1966** allocator is engaged to handle all of SQLites memory allocation needs.
1967** The first pointer (the memory pointer) must be aligned to an 8-byte
1968** boundary or subsequent behavior of SQLite will be undefined.
1969** The minimum allocation size is capped at 2**12. Reasonable values
1970** for the minimum allocation size are 2**5 through 2**8.</dd>
1971**
1972** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
1973** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a
1974** pointer to an instance of the [sqlite3_mutex_methods] structure.
1975** The argument specifies alternative low-level mutex routines to be used
1976** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of
1977** the content of the [sqlite3_mutex_methods] structure before the call to
1978** [sqlite3_config()] returns. ^If SQLite is compiled with
1979** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1980** the entire mutexing subsystem is omitted from the build and hence calls to
1981** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
1982** return [SQLITE_ERROR].</dd>
1983**
1984** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
1985** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which
1986** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The
1987** [sqlite3_mutex_methods]
1988** structure is filled with the currently defined mutex routines.)^
1989** This option can be used to overload the default mutex allocation
1990** routines with a wrapper used to track mutex usage for performance
1991** profiling or testing, for example. ^If SQLite is compiled with
1992** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1993** the entire mutexing subsystem is omitted from the build and hence calls to
1994** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
1995** return [SQLITE_ERROR].</dd>
1996**
1997** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
1998** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine
1999** the default size of [lookaside memory] on each [database connection].
2000** The first argument is the
2001** size of each lookaside buffer slot ("sz") and the second is the number of
2002** slots allocated to each database connection ("cnt").)^
2003** ^(SQLITE_CONFIG_LOOKASIDE sets the <i>default</i> lookaside size.
2004** The [SQLITE_DBCONFIG_LOOKASIDE] option to [sqlite3_db_config()] can
2005** be used to change the lookaside configuration on individual connections.)^
2006** The [-DSQLITE_DEFAULT_LOOKASIDE] option can be used to change the
2007** default lookaside configuration at compile-time.
2008** </dd>
2009**
2010** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt>
2011** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is
2012** a pointer to an [sqlite3_pcache_methods2] object. This object specifies
2013** the interface to a custom page cache implementation.)^
2014** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd>
2015**
2016** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>
2017** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which
2018** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of
2019** the current page cache implementation into that object.)^ </dd>
2020**
2021** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
2022** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite
2023** global [error log].
2024** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
2025** function with a call signature of void(*)(void*,int,const char*),
2026** and a pointer to void. ^If the function pointer is not NULL, it is
2027** invoked by [sqlite3_log()] to process each logging event. ^If the
2028** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
2029** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
2030** passed through as the first parameter to the application-defined logger
2031** function whenever that function is invoked. ^The second parameter to
2032** the logger function is a copy of the first parameter to the corresponding
2033** [sqlite3_log()] call and is intended to be a [result code] or an
2034** [extended result code]. ^The third parameter passed to the logger is
2035** log message after formatting via [sqlite3_snprintf()].
2036** The SQLite logging interface is not reentrant; the logger function
2037** supplied by the application must not invoke any SQLite interface.
2038** In a multi-threaded application, the application-defined logger
2039** function must be threadsafe. </dd>
2040**
2041** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
2042** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int.
2043** If non-zero, then URI handling is globally enabled. If the parameter is zero,
2044** then URI handling is globally disabled.)^ ^If URI handling is globally
2045** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()],
2046** [sqlite3_open16()] or
2047** specified as part of [ATTACH] commands are interpreted as URIs, regardless
2048** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
2049** connection is opened. ^If it is globally disabled, filenames are
2050** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
2051** database connection is opened. ^(By default, URI handling is globally
2052** disabled. The default value may be changed by compiling with the
2053** [SQLITE_USE_URI] symbol defined.)^
2054**
2055** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN
2056** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer
2057** argument which is interpreted as a boolean in order to enable or disable
2058** the use of covering indices for full table scans in the query optimizer.
2059** ^The default setting is determined
2060** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on"
2061** if that compile-time option is omitted.
2062** The ability to disable the use of covering indices for full table scans
2063** is because some incorrectly coded legacy applications might malfunction
2064** when the optimization is enabled. Providing the ability to
2065** disable the optimization allows the older, buggy application code to work
2066** without change even with newer versions of SQLite.
2067**
2068** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]]
2069** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE
2070** <dd> These options are obsolete and should not be used by new code.
2071** They are retained for backwards compatibility but are now no-ops.
2072** </dd>
2073**
2074** [[SQLITE_CONFIG_SQLLOG]]
2075** <dt>SQLITE_CONFIG_SQLLOG
2076** <dd>This option is only available if sqlite is compiled with the
2077** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should
2078** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int).
2079** The second should be of type (void*). The callback is invoked by the library
2080** in three separate circumstances, identified by the value passed as the
2081** fourth parameter. If the fourth parameter is 0, then the database connection
2082** passed as the second argument has just been opened. The third argument
2083** points to a buffer containing the name of the main database file. If the
2084** fourth parameter is 1, then the SQL statement that the third parameter
2085** points to has just been executed. Or, if the fourth parameter is 2, then
2086** the connection being passed as the second parameter is being closed. The
2087** third parameter is passed NULL In this case. An example of using this
2088** configuration option can be seen in the "test_sqllog.c" source file in
2089** the canonical SQLite source tree.</dd>
2090**
2091** [[SQLITE_CONFIG_MMAP_SIZE]]
2092** <dt>SQLITE_CONFIG_MMAP_SIZE
2093** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values
2094** that are the default mmap size limit (the default setting for
2095** [PRAGMA mmap_size]) and the maximum allowed mmap size limit.
2096** ^The default setting can be overridden by each database connection using
2097** either the [PRAGMA mmap_size] command, or by using the
2098** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size
2099** will be silently truncated if necessary so that it does not exceed the
2100** compile-time maximum mmap size set by the
2101** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^
2102** ^If either argument to this option is negative, then that argument is
2103** changed to its compile-time default.
2104**
2105** [[SQLITE_CONFIG_WIN32_HEAPSIZE]]
2106** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE
2107** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is
2108** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro
2109** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value
2110** that specifies the maximum size of the created heap.
2111**
2112** [[SQLITE_CONFIG_PCACHE_HDRSZ]]
2113** <dt>SQLITE_CONFIG_PCACHE_HDRSZ
2114** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which
2115** is a pointer to an integer and writes into that integer the number of extra
2116** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE].
2117** The amount of extra space required can change depending on the compiler,
2118** target platform, and SQLite version.
2119**
2120** [[SQLITE_CONFIG_PMASZ]]
2121** <dt>SQLITE_CONFIG_PMASZ
2122** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which
2123** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded
2124** sorter to that integer. The default minimum PMA Size is set by the
2125** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched
2126** to help with sort operations when multithreaded sorting
2127** is enabled (using the [PRAGMA threads] command) and the amount of content
2128** to be sorted exceeds the page size times the minimum of the
2129** [PRAGMA cache_size] setting and this value.
2130**
2131** [[SQLITE_CONFIG_STMTJRNL_SPILL]]
2132** <dt>SQLITE_CONFIG_STMTJRNL_SPILL
2133** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which
2134** becomes the [statement journal] spill-to-disk threshold.
2135** [Statement journals] are held in memory until their size (in bytes)
2136** exceeds this threshold, at which point they are written to disk.
2137** Or if the threshold is -1, statement journals are always held
2138** exclusively in memory.
2139** Since many statement journals never become large, setting the spill
2140** threshold to a value such as 64KiB can greatly reduce the amount of
2141** I/O required to support statement rollback.
2142** The default value for this setting is controlled by the
2143** [SQLITE_STMTJRNL_SPILL] compile-time option.
2144**
2145** [[SQLITE_CONFIG_SORTERREF_SIZE]]
2146** <dt>SQLITE_CONFIG_SORTERREF_SIZE
2147** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter
2148** of type (int) - the new value of the sorter-reference size threshold.
2149** Usually, when SQLite uses an external sort to order records according
2150** to an ORDER BY clause, all fields required by the caller are present in the
2151** sorted records. However, if SQLite determines based on the declared type
2152** of a table column that its values are likely to be very large - larger
2153** than the configured sorter-reference size threshold - then a reference
2154** is stored in each sorted record and the required column values loaded
2155** from the database as records are returned in sorted order. The default
2156** value for this option is to never use this optimization. Specifying a
2157** negative value for this option restores the default behavior.
2158** This option is only available if SQLite is compiled with the
2159** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option.
2160**
2161** [[SQLITE_CONFIG_MEMDB_MAXSIZE]]
2162** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE
2163** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter
2164** [sqlite3_int64] parameter which is the default maximum size for an in-memory
2165** database created using [sqlite3_deserialize()]. This default maximum
2166** size can be adjusted up or down for individual databases using the
2167** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this
2168** configuration setting is never used, then the default maximum is determined
2169** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that
2170** compile-time option is not set, then the default maximum is 1073741824.
2171**
2172** [[SQLITE_CONFIG_ROWID_IN_VIEW]]
2173** <dt>SQLITE_CONFIG_ROWID_IN_VIEW
2174** <dd>The SQLITE_CONFIG_ROWID_IN_VIEW option enables or disables the ability
2175** for VIEWs to have a ROWID. The capability can only be enabled if SQLite is
2176** compiled with -DSQLITE_ALLOW_ROWID_IN_VIEW, in which case the capability
2177** defaults to on. This configuration option queries the current setting or
2178** changes the setting to off or on. The argument is a pointer to an integer.
2179** If that integer initially holds a value of 1, then the ability for VIEWs to
2180** have ROWIDs is activated. If the integer initially holds zero, then the
2181** ability is deactivated. Any other initial value for the integer leaves the
2182** setting unchanged. After changes, if any, the integer is written with
2183** a 1 or 0, if the ability for VIEWs to have ROWIDs is on or off. If SQLite
2184** is compiled without -DSQLITE_ALLOW_ROWID_IN_VIEW (which is the usual and
2185** recommended case) then the integer is always filled with zero, regardless
2186** if its initial value.
2187** </dl>
2188*/
2189#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */
2190#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */
2191#define SQLITE_CONFIG_SERIALIZED 3 /* nil */
2192#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */
2193#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */
2194#define SQLITE_CONFIG_SCRATCH 6 /* No longer used */
2195#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */
2196#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */
2197#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */
2198#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */
2199#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */
2200/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */
2201#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */
2202#define SQLITE_CONFIG_PCACHE 14 /* no-op */
2203#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */
2204#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */
2205#define SQLITE_CONFIG_URI 17 /* int */
2206#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */
2207#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */
2208#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */
2209#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */
2210#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */
2211#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */
2212#define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */
2213#define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */
2214#define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */
2215#define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */
2216#define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */
2217#define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */
2218#define SQLITE_CONFIG_ROWID_IN_VIEW 30 /* int* */
2219
2220/*
2221** CAPI3REF: Database Connection Configuration Options
2222**
2223** These constants are the available integer configuration options that
2224** can be passed as the second parameter to the [sqlite3_db_config()] interface.
2225**
2226** The [sqlite3_db_config()] interface is a var-args functions. It takes a
2227** variable number of parameters, though always at least two. The number of
2228** parameters passed into sqlite3_db_config() depends on which of these
2229** constants is given as the second parameter. This documentation page
2230** refers to parameters beyond the second as "arguments". Thus, when this
2231** page says "the N-th argument" it means "the N-th parameter past the
2232** configuration option" or "the (N+2)-th parameter to sqlite3_db_config()".
2233**
2234** New configuration options may be added in future releases of SQLite.
2235** Existing configuration options might be discontinued. Applications
2236** should check the return code from [sqlite3_db_config()] to make sure that
2237** the call worked. ^The [sqlite3_db_config()] interface will return a
2238** non-zero [error code] if a discontinued or unsupported configuration option
2239** is invoked.
2240**
2241** <dl>
2242** [[SQLITE_DBCONFIG_LOOKASIDE]]
2243** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
2244** <dd> The SQLITE_DBCONFIG_LOOKASIDE option is used to adjust the
2245** configuration of the [lookaside memory allocator] within a database
2246** connection.
2247** The arguments to the SQLITE_DBCONFIG_LOOKASIDE option are <i>not</i>
2248** in the [DBCONFIG arguments|usual format].
2249** The SQLITE_DBCONFIG_LOOKASIDE option takes three arguments, not two,
2250** so that a call to [sqlite3_db_config()] that uses SQLITE_DBCONFIG_LOOKASIDE
2251** should have a total of five parameters.
2252** <ol>
2253** <li><p>The first argument ("buf") is a
2254** pointer to a memory buffer to use for lookaside memory.
2255** The first argument may be NULL in which case SQLite will allocate the
2256** lookaside buffer itself using [sqlite3_malloc()].
2257** <li><P>The second argument ("sz") is the
2258** size of each lookaside buffer slot. Lookaside is disabled if "sz"
2259** is less than 8. The "sz" argument should be a multiple of 8 less than
2260** 65536. If "sz" does not meet this constraint, it is reduced in size until
2261** it does.
2262** <li><p>The third argument ("cnt") is the number of slots. Lookaside is disabled
2263** if "cnt"is less than 1. The "cnt" value will be reduced, if necessary, so
2264** that the product of "sz" and "cnt" does not exceed 2,147,418,112. The "cnt"
2265** parameter is usually chosen so that the product of "sz" and "cnt" is less
2266** than 1,000,000.
2267** </ol>
2268** <p>If the "buf" argument is not NULL, then it must
2269** point to a memory buffer with a size that is greater than
2270** or equal to the product of "sz" and "cnt".
2271** The buffer must be aligned to an 8-byte boundary.
2272** The lookaside memory
2273** configuration for a database connection can only be changed when that
2274** connection is not currently using lookaside memory, or in other words
2275** when the value returned by [SQLITE_DBSTATUS_LOOKASIDE_USED] is zero.
2276** Any attempt to change the lookaside memory configuration when lookaside
2277** memory is in use leaves the configuration unchanged and returns
2278** [SQLITE_BUSY].
2279** If the "buf" argument is NULL and an attempt
2280** to allocate memory based on "sz" and "cnt" fails, then
2281** lookaside is silently disabled.
2282** <p>
2283** The [SQLITE_CONFIG_LOOKASIDE] configuration option can be used to set the
2284** default lookaside configuration at initialization. The
2285** [-DSQLITE_DEFAULT_LOOKASIDE] option can be used to set the default lookaside
2286** configuration at compile-time. Typical values for lookaside are 1200 for
2287** "sz" and 40 to 100 for "cnt".
2288** </dd>
2289**
2290** [[SQLITE_DBCONFIG_ENABLE_FKEY]]
2291** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt>
2292** <dd> ^This option is used to enable or disable the enforcement of
2293** [foreign key constraints]. This is the same setting that is
2294** enabled or disabled by the [PRAGMA foreign_keys] statement.
2295** The first argument is an integer which is 0 to disable FK enforcement,
2296** positive to enable FK enforcement or negative to leave FK enforcement
2297** unchanged. The second parameter is a pointer to an integer into which
2298** is written 0 or 1 to indicate whether FK enforcement is off or on
2299** following this call. The second parameter may be a NULL pointer, in
2300** which case the FK enforcement setting is not reported back. </dd>
2301**
2302** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]]
2303** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>
2304** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
2305** There should be two additional arguments.
2306** The first argument is an integer which is 0 to disable triggers,
2307** positive to enable triggers or negative to leave the setting unchanged.
2308** The second parameter is a pointer to an integer into which
2309** is written 0 or 1 to indicate whether triggers are disabled or enabled
2310** following this call. The second parameter may be a NULL pointer, in
2311** which case the trigger setting is not reported back.
2312**
2313** <p>Originally this option disabled all triggers. ^(However, since
2314** SQLite version 3.35.0, TEMP triggers are still allowed even if
2315** this option is off. So, in other words, this option now only disables
2316** triggers in the main database schema or in the schemas of [ATTACH]-ed
2317** databases.)^ </dd>
2318**
2319** [[SQLITE_DBCONFIG_ENABLE_VIEW]]
2320** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt>
2321** <dd> ^This option is used to enable or disable [CREATE VIEW | views].
2322** There must be two additional arguments.
2323** The first argument is an integer which is 0 to disable views,
2324** positive to enable views or negative to leave the setting unchanged.
2325** The second parameter is a pointer to an integer into which
2326** is written 0 or 1 to indicate whether views are disabled or enabled
2327** following this call. The second parameter may be a NULL pointer, in
2328** which case the view setting is not reported back.
2329**
2330** <p>Originally this option disabled all views. ^(However, since
2331** SQLite version 3.35.0, TEMP views are still allowed even if
2332** this option is off. So, in other words, this option now only disables
2333** views in the main database schema or in the schemas of ATTACH-ed
2334** databases.)^ </dd>
2335**
2336** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]]
2337** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt>
2338** <dd> ^This option is used to enable or disable the
2339** [fts3_tokenizer()] function which is part of the
2340** [FTS3] full-text search engine extension.
2341** There must be two additional arguments.
2342** The first argument is an integer which is 0 to disable fts3_tokenizer() or
2343** positive to enable fts3_tokenizer() or negative to leave the setting
2344** unchanged.
2345** The second parameter is a pointer to an integer into which
2346** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled
2347** following this call. The second parameter may be a NULL pointer, in
2348** which case the new setting is not reported back. </dd>
2349**
2350** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]]
2351** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt>
2352** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()]
2353** interface independently of the [load_extension()] SQL function.
2354** The [sqlite3_enable_load_extension()] API enables or disables both the
2355** C-API [sqlite3_load_extension()] and the SQL function [load_extension()].
2356** There must be two additional arguments.
2357** When the first argument to this interface is 1, then only the C-API is
2358** enabled and the SQL function remains disabled. If the first argument to
2359** this interface is 0, then both the C-API and the SQL function are disabled.
2360** If the first argument is -1, then no changes are made to state of either the
2361** C-API or the SQL function.
2362** The second parameter is a pointer to an integer into which
2363** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface
2364** is disabled or enabled following this call. The second parameter may
2365** be a NULL pointer, in which case the new setting is not reported back.
2366** </dd>
2367**
2368** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt>
2369** <dd> ^This option is used to change the name of the "main" database
2370** schema. This option does not follow the
2371** [DBCONFIG arguments|usual SQLITE_DBCONFIG argument format].
2372** This option takes exactly one additional argument so that the
2373** [sqlite3_db_config()] call has a total of three parameters. The
2374** extra argument must be a pointer to a constant UTF8 string which
2375** will become the new schema name in place of "main". ^SQLite does
2376** not make a copy of the new main schema name string, so the application
2377** must ensure that the argument passed into SQLITE_DBCONFIG MAINDBNAME
2378** is unchanged until after the database connection closes.
2379** </dd>
2380**
2381** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]]
2382** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt>
2383** <dd> Usually, when a database in [WAL mode] is closed or detached from a
2384** database handle, SQLite checks if if there are other connections to the
2385** same database, and if there are no other database connection (if the
2386** connection being closed is the last open connection to the database),
2387** then SQLite performs a [checkpoint] before closing the connection and
2388** deletes the WAL file. The SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE option can
2389** be used to override that behavior. The first argument passed to this
2390** operation (the third parameter to [sqlite3_db_config()]) is an integer
2391** which is positive to disable checkpoints-on-close, or zero (the default)
2392** to enable them, and negative to leave the setting unchanged.
2393** The second argument (the fourth parameter) is a pointer to an integer
2394** into which is written 0 or 1 to indicate whether checkpoints-on-close
2395** have been disabled - 0 if they are not disabled, 1 if they are.
2396** </dd>
2397**
2398** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt>
2399** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates
2400** the [query planner stability guarantee] (QPSG). When the QPSG is active,
2401** a single SQL query statement will always use the same algorithm regardless
2402** of values of [bound parameters].)^ The QPSG disables some query optimizations
2403** that look at the values of bound parameters, which can make some queries
2404** slower. But the QPSG has the advantage of more predictable behavior. With
2405** the QPSG active, SQLite will always use the same query plan in the field as
2406** was used during testing in the lab.
2407** The first argument to this setting is an integer which is 0 to disable
2408** the QPSG, positive to enable QPSG, or negative to leave the setting
2409** unchanged. The second parameter is a pointer to an integer into which
2410** is written 0 or 1 to indicate whether the QPSG is disabled or enabled
2411** following this call.
2412** </dd>
2413**
2414** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt>
2415** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not
2416** include output for any operations performed by trigger programs. This
2417** option is used to set or clear (the default) a flag that governs this
2418** behavior. The first parameter passed to this operation is an integer -
2419** positive to enable output for trigger programs, or zero to disable it,
2420** or negative to leave the setting unchanged.
2421** The second parameter is a pointer to an integer into which is written
2422** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if
2423** it is not disabled, 1 if it is.
2424** </dd>
2425**
2426** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt>
2427** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run
2428** [VACUUM] in order to reset a database back to an empty database
2429** with no schema and no content. The following process works even for
2430** a badly corrupted database file:
2431** <ol>
2432** <li> If the database connection is newly opened, make sure it has read the
2433** database schema by preparing then discarding some query against the
2434** database, or calling sqlite3_table_column_metadata(), ignoring any
2435** errors. This step is only necessary if the application desires to keep
2436** the database in WAL mode after the reset if it was in WAL mode before
2437** the reset.
2438** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0);
2439** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0);
2440** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0);
2441** </ol>
2442** Because resetting a database is destructive and irreversible, the
2443** process requires the use of this obscure API and multiple steps to
2444** help ensure that it does not happen by accident. Because this
2445** feature must be capable of resetting corrupt databases, and
2446** shutting down virtual tables may require access to that corrupt
2447** storage, the library must abandon any installed virtual tables
2448** without calling their xDestroy() methods.
2449**
2450** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt>
2451** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the
2452** "defensive" flag for a database connection. When the defensive
2453** flag is enabled, language features that allow ordinary SQL to
2454** deliberately corrupt the database file are disabled. The disabled
2455** features include but are not limited to the following:
2456** <ul>
2457** <li> The [PRAGMA writable_schema=ON] statement.
2458** <li> The [PRAGMA journal_mode=OFF] statement.
2459** <li> The [PRAGMA schema_version=N] statement.
2460** <li> Writes to the [sqlite_dbpage] virtual table.
2461** <li> Direct writes to [shadow tables].
2462** </ul>
2463** </dd>
2464**
2465** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt>
2466** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the
2467** "writable_schema" flag. This has the same effect and is logically equivalent
2468** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF].
2469** The first argument to this setting is an integer which is 0 to disable
2470** the writable_schema, positive to enable writable_schema, or negative to
2471** leave the setting unchanged. The second parameter is a pointer to an
2472** integer into which is written 0 or 1 to indicate whether the writable_schema
2473** is enabled or disabled following this call.
2474** </dd>
2475**
2476** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]]
2477** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt>
2478** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates
2479** the legacy behavior of the [ALTER TABLE RENAME] command such it
2480** behaves as it did prior to [version 3.24.0] (2018-06-04). See the
2481** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for
2482** additional information. This feature can also be turned on and off
2483** using the [PRAGMA legacy_alter_table] statement.
2484** </dd>
2485**
2486** [[SQLITE_DBCONFIG_DQS_DML]]
2487** <dt>SQLITE_DBCONFIG_DQS_DML</dt>
2488** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates
2489** the legacy [double-quoted string literal] misfeature for DML statements
2490** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The
2491** default value of this setting is determined by the [-DSQLITE_DQS]
2492** compile-time option.
2493** </dd>
2494**
2495** [[SQLITE_DBCONFIG_DQS_DDL]]
2496** <dt>SQLITE_DBCONFIG_DQS_DDL</dt>
2497** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates
2498** the legacy [double-quoted string literal] misfeature for DDL statements,
2499** such as CREATE TABLE and CREATE INDEX. The
2500** default value of this setting is determined by the [-DSQLITE_DQS]
2501** compile-time option.
2502** </dd>
2503**
2504** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]]
2505** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</dt>
2506** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to
2507** assume that database schemas are untainted by malicious content.
2508** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite
2509** takes additional defensive steps to protect the application from harm
2510** including:
2511** <ul>
2512** <li> Prohibit the use of SQL functions inside triggers, views,
2513** CHECK constraints, DEFAULT clauses, expression indexes,
2514** partial indexes, or generated columns
2515** unless those functions are tagged with [SQLITE_INNOCUOUS].
2516** <li> Prohibit the use of virtual tables inside of triggers or views
2517** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS].
2518** </ul>
2519** This setting defaults to "on" for legacy compatibility, however
2520** all applications are advised to turn it off if possible. This setting
2521** can also be controlled using the [PRAGMA trusted_schema] statement.
2522** </dd>
2523**
2524** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]]
2525** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</dt>
2526** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates
2527** the legacy file format flag. When activated, this flag causes all newly
2528** created database file to have a schema format version number (the 4-byte
2529** integer found at offset 44 into the database header) of 1. This in turn
2530** means that the resulting database file will be readable and writable by
2531** any SQLite version back to 3.0.0 ([dateof:3.0.0]). Without this setting,
2532** newly created databases are generally not understandable by SQLite versions
2533** prior to 3.3.0 ([dateof:3.3.0]). As these words are written, there
2534** is now scarcely any need to generate database files that are compatible
2535** all the way back to version 3.0.0, and so this setting is of little
2536** practical use, but is provided so that SQLite can continue to claim the
2537** ability to generate new database files that are compatible with version
2538** 3.0.0.
2539** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on,
2540** the [VACUUM] command will fail with an obscure error when attempting to
2541** process a table with generated columns and a descending index. This is
2542** not considered a bug since SQLite versions 3.3.0 and earlier do not support
2543** either generated columns or descending indexes.
2544** </dd>
2545**
2546** [[SQLITE_DBCONFIG_STMT_SCANSTATUS]]
2547** <dt>SQLITE_DBCONFIG_STMT_SCANSTATUS</dt>
2548** <dd>The SQLITE_DBCONFIG_STMT_SCANSTATUS option is only useful in
2549** SQLITE_ENABLE_STMT_SCANSTATUS builds. In this case, it sets or clears
2550** a flag that enables collection of the sqlite3_stmt_scanstatus_v2()
2551** statistics. For statistics to be collected, the flag must be set on
2552** the database handle both when the SQL statement is prepared and when it
2553** is stepped. The flag is set (collection of statistics is enabled)
2554** by default. <p>This option takes two arguments: an integer and a pointer to
2555** an integer.. The first argument is 1, 0, or -1 to enable, disable, or
2556** leave unchanged the statement scanstatus option. If the second argument
2557** is not NULL, then the value of the statement scanstatus setting after
2558** processing the first argument is written into the integer that the second
2559** argument points to.
2560** </dd>
2561**
2562** [[SQLITE_DBCONFIG_REVERSE_SCANORDER]]
2563** <dt>SQLITE_DBCONFIG_REVERSE_SCANORDER</dt>
2564** <dd>The SQLITE_DBCONFIG_REVERSE_SCANORDER option changes the default order
2565** in which tables and indexes are scanned so that the scans start at the end
2566** and work toward the beginning rather than starting at the beginning and
2567** working toward the end. Setting SQLITE_DBCONFIG_REVERSE_SCANORDER is the
2568** same as setting [PRAGMA reverse_unordered_selects]. <p>This option takes
2569** two arguments which are an integer and a pointer to an integer. The first
2570** argument is 1, 0, or -1 to enable, disable, or leave unchanged the
2571** reverse scan order flag, respectively. If the second argument is not NULL,
2572** then 0 or 1 is written into the integer that the second argument points to
2573** depending on if the reverse scan order flag is set after processing the
2574** first argument.
2575** </dd>
2576**
2577** [[SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE]]
2578** <dt>SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE</dt>
2579** <dd>The SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE option enables or disables
2580** the ability of the [ATTACH DATABASE] SQL command to create a new database
2581** file if the database filed named in the ATTACH command does not already
2582** exist. This ability of ATTACH to create a new database is enabled by
2583** default. Applications can disable or reenable the ability for ATTACH to
2584** create new database files using this DBCONFIG option.<p>
2585** This option takes two arguments which are an integer and a pointer
2586** to an integer. The first argument is 1, 0, or -1 to enable, disable, or
2587** leave unchanged the attach-create flag, respectively. If the second
2588** argument is not NULL, then 0 or 1 is written into the integer that the
2589** second argument points to depending on if the attach-create flag is set
2590** after processing the first argument.
2591** </dd>
2592**
2593** [[SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE]]
2594** <dt>SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE</dt>
2595** <dd>The SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE option enables or disables the
2596** ability of the [ATTACH DATABASE] SQL command to open a database for writing.
2597** This capability is enabled by default. Applications can disable or
2598** reenable this capability using the current DBCONFIG option. If the
2599** the this capability is disabled, the [ATTACH] command will still work,
2600** but the database will be opened read-only. If this option is disabled,
2601** then the ability to create a new database using [ATTACH] is also disabled,
2602** regardless of the value of the [SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE]
2603** option.<p>
2604** This option takes two arguments which are an integer and a pointer
2605** to an integer. The first argument is 1, 0, or -1 to enable, disable, or
2606** leave unchanged the ability to ATTACH another database for writing,
2607** respectively. If the second argument is not NULL, then 0 or 1 is written
2608** into the integer to which the second argument points, depending on whether
2609** the ability to ATTACH a read/write database is enabled or disabled
2610** after processing the first argument.
2611** </dd>
2612**
2613** [[SQLITE_DBCONFIG_ENABLE_COMMENTS]]
2614** <dt>SQLITE_DBCONFIG_ENABLE_COMMENTS</dt>
2615** <dd>The SQLITE_DBCONFIG_ENABLE_COMMENTS option enables or disables the
2616** ability to include comments in SQL text. Comments are enabled by default.
2617** An application can disable or reenable comments in SQL text using this
2618** DBCONFIG option.<p>
2619** This option takes two arguments which are an integer and a pointer
2620** to an integer. The first argument is 1, 0, or -1 to enable, disable, or
2621** leave unchanged the ability to use comments in SQL text,
2622** respectively. If the second argument is not NULL, then 0 or 1 is written
2623** into the integer that the second argument points to depending on if
2624** comments are allowed in SQL text after processing the first argument.
2625** </dd>
2626**
2627** </dl>
2628**
2629** [[DBCONFIG arguments]] <h3>Arguments To SQLITE_DBCONFIG Options</h3>
2630**
2631** <p>Most of the SQLITE_DBCONFIG options take two arguments, so that the
2632** overall call to [sqlite3_db_config()] has a total of four parameters.
2633** The first argument (the third parameter to sqlite3_db_config()) is a integer.
2634** The second argument is a pointer to an integer. If the first argument is 1,
2635** then the option becomes enabled. If the first integer argument is 0, then the
2636** option is disabled. If the first argument is -1, then the option setting
2637** is unchanged. The second argument, the pointer to an integer, may be NULL.
2638** If the second argument is not NULL, then a value of 0 or 1 is written into
2639** the integer to which the second argument points, depending on whether the
2640** setting is disabled or enabled after applying any changes specified by
2641** the first argument.
2642**
2643** <p>While most SQLITE_DBCONFIG options use the argument format
2644** described in the previous paragraph, the [SQLITE_DBCONFIG_MAINDBNAME]
2645** and [SQLITE_DBCONFIG_LOOKASIDE] options are different. See the
2646** documentation of those exceptional options for details.
2647*/
2648#define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */
2649#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */
2650#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */
2651#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */
2652#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */
2653#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */
2654#define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */
2655#define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */
2656#define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */
2657#define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */
2658#define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */
2659#define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */
2660#define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */
2661#define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */
2662#define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */
2663#define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */
2664#define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT 1016 /* int int* */
2665#define SQLITE_DBCONFIG_TRUSTED_SCHEMA 1017 /* int int* */
2666#define SQLITE_DBCONFIG_STMT_SCANSTATUS 1018 /* int int* */
2667#define SQLITE_DBCONFIG_REVERSE_SCANORDER 1019 /* int int* */
2668#define SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE 1020 /* int int* */
2669#define SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE 1021 /* int int* */
2670#define SQLITE_DBCONFIG_ENABLE_COMMENTS 1022 /* int int* */
2671#define SQLITE_DBCONFIG_MAX 1022 /* Largest DBCONFIG */
2672
2673/*
2674** CAPI3REF: Enable Or Disable Extended Result Codes
2675** METHOD: sqlite3
2676**
2677** ^The sqlite3_extended_result_codes() routine enables or disables the
2678** [extended result codes] feature of SQLite. ^The extended result
2679** codes are disabled by default for historical compatibility.
2680*/
2681SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);
2682
2683/*
2684** CAPI3REF: Last Insert Rowid
2685** METHOD: sqlite3
2686**
2687** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables)
2688** has a unique 64-bit signed
2689** integer key called the [ROWID | "rowid"]. ^The rowid is always available
2690** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
2691** names are not also used by explicitly declared columns. ^If
2692** the table has a column of type [INTEGER PRIMARY KEY] then that column
2693** is another alias for the rowid.
2694**
2695** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of
2696** the most recent successful [INSERT] into a rowid table or [virtual table]
2697** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not
2698** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred
2699** on the database connection D, then sqlite3_last_insert_rowid(D) returns
2700** zero.
2701**
2702** As well as being set automatically as rows are inserted into database
2703** tables, the value returned by this function may be set explicitly by
2704** [sqlite3_set_last_insert_rowid()]
2705**
2706** Some virtual table implementations may INSERT rows into rowid tables as
2707** part of committing a transaction (e.g. to flush data accumulated in memory
2708** to disk). In this case subsequent calls to this function return the rowid
2709** associated with these internal INSERT operations, which leads to
2710** unintuitive results. Virtual table implementations that do write to rowid
2711** tables in this way can avoid this problem by restoring the original
2712** rowid value using [sqlite3_set_last_insert_rowid()] before returning
2713** control to the user.
2714**
2715** ^(If an [INSERT] occurs within a trigger then this routine will
2716** return the [rowid] of the inserted row as long as the trigger is
2717** running. Once the trigger program ends, the value returned
2718** by this routine reverts to what it was before the trigger was fired.)^
2719**
2720** ^An [INSERT] that fails due to a constraint violation is not a
2721** successful [INSERT] and does not change the value returned by this
2722** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
2723** and INSERT OR ABORT make no changes to the return value of this
2724** routine when their insertion fails. ^(When INSERT OR REPLACE
2725** encounters a constraint violation, it does not fail. The
2726** INSERT continues to completion after deleting rows that caused
2727** the constraint problem so INSERT OR REPLACE will always change
2728** the return value of this interface.)^
2729**
2730** ^For the purposes of this routine, an [INSERT] is considered to
2731** be successful even if it is subsequently rolled back.
2732**
2733** This function is accessible to SQL statements via the
2734** [last_insert_rowid() SQL function].
2735**
2736** If a separate thread performs a new [INSERT] on the same
2737** database connection while the [sqlite3_last_insert_rowid()]
2738** function is running and thus changes the last insert [rowid],
2739** then the value returned by [sqlite3_last_insert_rowid()] is
2740** unpredictable and might not equal either the old or the new
2741** last insert [rowid].
2742*/
2743SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);
2744
2745/*
2746** CAPI3REF: Set the Last Insert Rowid value.
2747** METHOD: sqlite3
2748**
2749** The sqlite3_set_last_insert_rowid(D, R) method allows the application to
2750** set the value returned by calling sqlite3_last_insert_rowid(D) to R
2751** without inserting a row into the database.
2752*/
2753SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64);
2754
2755/*
2756** CAPI3REF: Count The Number Of Rows Modified
2757** METHOD: sqlite3
2758**
2759** ^These functions return the number of rows modified, inserted or
2760** deleted by the most recently completed INSERT, UPDATE or DELETE
2761** statement on the database connection specified by the only parameter.
2762** The two functions are identical except for the type of the return value
2763** and that if the number of rows modified by the most recent INSERT, UPDATE,
2764** or DELETE is greater than the maximum value supported by type "int", then
2765** the return value of sqlite3_changes() is undefined. ^Executing any other
2766** type of SQL statement does not modify the value returned by these functions.
2767** For the purposes of this interface, a CREATE TABLE AS SELECT statement
2768** does not count as an INSERT, UPDATE or DELETE statement and hence the rows
2769** added to the new table by the CREATE TABLE AS SELECT statement are not
2770** counted.
2771**
2772** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are
2773** considered - auxiliary changes caused by [CREATE TRIGGER | triggers],
2774** [foreign key actions] or [REPLACE] constraint resolution are not counted.
2775**
2776** Changes to a view that are intercepted by
2777** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value
2778** returned by sqlite3_changes() immediately after an INSERT, UPDATE or
2779** DELETE statement run on a view is always zero. Only changes made to real
2780** tables are counted.
2781**
2782** Things are more complicated if the sqlite3_changes() function is
2783** executed while a trigger program is running. This may happen if the
2784** program uses the [changes() SQL function], or if some other callback
2785** function invokes sqlite3_changes() directly. Essentially:
2786**
2787** <ul>
2788** <li> ^(Before entering a trigger program the value returned by
2789** sqlite3_changes() function is saved. After the trigger program
2790** has finished, the original value is restored.)^
2791**
2792** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE
2793** statement sets the value returned by sqlite3_changes()
2794** upon completion as normal. Of course, this value will not include
2795** any changes performed by sub-triggers, as the sqlite3_changes()
2796** value will be saved and restored after each sub-trigger has run.)^
2797** </ul>
2798**
2799** ^This means that if the changes() SQL function (or similar) is used
2800** by the first INSERT, UPDATE or DELETE statement within a trigger, it
2801** returns the value as set when the calling statement began executing.
2802** ^If it is used by the second or subsequent such statement within a trigger
2803** program, the value returned reflects the number of rows modified by the
2804** previous INSERT, UPDATE or DELETE statement within the same trigger.
2805**
2806** If a separate thread makes changes on the same database connection
2807** while [sqlite3_changes()] is running then the value returned
2808** is unpredictable and not meaningful.
2809**
2810** See also:
2811** <ul>
2812** <li> the [sqlite3_total_changes()] interface
2813** <li> the [count_changes pragma]
2814** <li> the [changes() SQL function]
2815** <li> the [data_version pragma]
2816** </ul>
2817*/
2818SQLITE_API int sqlite3_changes(sqlite3*);
2819SQLITE_API sqlite3_int64 sqlite3_changes64(sqlite3*);
2820
2821/*
2822** CAPI3REF: Total Number Of Rows Modified
2823** METHOD: sqlite3
2824**
2825** ^These functions return the total number of rows inserted, modified or
2826** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed
2827** since the database connection was opened, including those executed as
2828** part of trigger programs. The two functions are identical except for the
2829** type of the return value and that if the number of rows modified by the
2830** connection exceeds the maximum value supported by type "int", then
2831** the return value of sqlite3_total_changes() is undefined. ^Executing
2832** any other type of SQL statement does not affect the value returned by
2833** sqlite3_total_changes().
2834**
2835** ^Changes made as part of [foreign key actions] are included in the
2836** count, but those made as part of REPLACE constraint resolution are
2837** not. ^Changes to a view that are intercepted by INSTEAD OF triggers
2838** are not counted.
2839**
2840** The [sqlite3_total_changes(D)] interface only reports the number
2841** of rows that changed due to SQL statement run against database
2842** connection D. Any changes by other database connections are ignored.
2843** To detect changes against a database file from other database
2844** connections use the [PRAGMA data_version] command or the
2845** [SQLITE_FCNTL_DATA_VERSION] [file control].
2846**
2847** If a separate thread makes changes on the same database connection
2848** while [sqlite3_total_changes()] is running then the value
2849** returned is unpredictable and not meaningful.
2850**
2851** See also:
2852** <ul>
2853** <li> the [sqlite3_changes()] interface
2854** <li> the [count_changes pragma]
2855** <li> the [changes() SQL function]
2856** <li> the [data_version pragma]
2857** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control]
2858** </ul>
2859*/
2860SQLITE_API int sqlite3_total_changes(sqlite3*);
2861SQLITE_API sqlite3_int64 sqlite3_total_changes64(sqlite3*);
2862
2863/*
2864** CAPI3REF: Interrupt A Long-Running Query
2865** METHOD: sqlite3
2866**
2867** ^This function causes any pending database operation to abort and
2868** return at its earliest opportunity. This routine is typically
2869** called in response to a user action such as pressing "Cancel"
2870** or Ctrl-C where the user wants a long query operation to halt
2871** immediately.
2872**
2873** ^It is safe to call this routine from a thread different from the
2874** thread that is currently running the database operation. But it
2875** is not safe to call this routine with a [database connection] that
2876** is closed or might close before sqlite3_interrupt() returns.
2877**
2878** ^If an SQL operation is very nearly finished at the time when
2879** sqlite3_interrupt() is called, then it might not have an opportunity
2880** to be interrupted and might continue to completion.
2881**
2882** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
2883** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
2884** that is inside an explicit transaction, then the entire transaction
2885** will be rolled back automatically.
2886**
2887** ^The sqlite3_interrupt(D) call is in effect until all currently running
2888** SQL statements on [database connection] D complete. ^Any new SQL statements
2889** that are started after the sqlite3_interrupt() call and before the
2890** running statement count reaches zero are interrupted as if they had been
2891** running prior to the sqlite3_interrupt() call. ^New SQL statements
2892** that are started after the running statement count reaches zero are
2893** not effected by the sqlite3_interrupt().
2894** ^A call to sqlite3_interrupt(D) that occurs when there are no running
2895** SQL statements is a no-op and has no effect on SQL statements
2896** that are started after the sqlite3_interrupt() call returns.
2897**
2898** ^The [sqlite3_is_interrupted(D)] interface can be used to determine whether
2899** or not an interrupt is currently in effect for [database connection] D.
2900** It returns 1 if an interrupt is currently in effect, or 0 otherwise.
2901*/
2902SQLITE_API void sqlite3_interrupt(sqlite3*);
2903SQLITE_API int sqlite3_is_interrupted(sqlite3*);
2904
2905/*
2906** CAPI3REF: Determine If An SQL Statement Is Complete
2907**
2908** These routines are useful during command-line input to determine if the
2909** currently entered text seems to form a complete SQL statement or
2910** if additional input is needed before sending the text into
2911** SQLite for parsing. ^These routines return 1 if the input string
2912** appears to be a complete SQL statement. ^A statement is judged to be
2913** complete if it ends with a semicolon token and is not a prefix of a
2914** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within
2915** string literals or quoted identifier names or comments are not
2916** independent tokens (they are part of the token in which they are
2917** embedded) and thus do not count as a statement terminator. ^Whitespace
2918** and comments that follow the final semicolon are ignored.
2919**
2920** ^These routines return 0 if the statement is incomplete. ^If a
2921** memory allocation fails, then SQLITE_NOMEM is returned.
2922**
2923** ^These routines do not parse the SQL statements thus
2924** will not detect syntactically incorrect SQL.
2925**
2926** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior
2927** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
2928** automatically by sqlite3_complete16(). If that initialization fails,
2929** then the return value from sqlite3_complete16() will be non-zero
2930** regardless of whether or not the input SQL is complete.)^
2931**
2932** The input to [sqlite3_complete()] must be a zero-terminated
2933** UTF-8 string.
2934**
2935** The input to [sqlite3_complete16()] must be a zero-terminated
2936** UTF-16 string in native byte order.
2937*/
2938SQLITE_API int sqlite3_complete(const char *sql);
2939SQLITE_API int sqlite3_complete16(const void *sql);
2940
2941/*
2942** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
2943** KEYWORDS: {busy-handler callback} {busy handler}
2944** METHOD: sqlite3
2945**
2946** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X
2947** that might be invoked with argument P whenever
2948** an attempt is made to access a database table associated with
2949** [database connection] D when another thread
2950** or process has the table locked.
2951** The sqlite3_busy_handler() interface is used to implement
2952** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout].
2953**
2954** ^If the busy callback is NULL, then [SQLITE_BUSY]
2955** is returned immediately upon encountering the lock. ^If the busy callback
2956** is not NULL, then the callback might be invoked with two arguments.
2957**
2958** ^The first argument to the busy handler is a copy of the void* pointer which
2959** is the third argument to sqlite3_busy_handler(). ^The second argument to
2960** the busy handler callback is the number of times that the busy handler has
2961** been invoked previously for the same locking event. ^If the
2962** busy callback returns 0, then no additional attempts are made to
2963** access the database and [SQLITE_BUSY] is returned
2964** to the application.
2965** ^If the callback returns non-zero, then another attempt
2966** is made to access the database and the cycle repeats.
2967**
2968** The presence of a busy handler does not guarantee that it will be invoked
2969** when there is lock contention. ^If SQLite determines that invoking the busy
2970** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
2971** to the application instead of invoking the
2972** busy handler.
2973** Consider a scenario where one process is holding a read lock that
2974** it is trying to promote to a reserved lock and
2975** a second process is holding a reserved lock that it is trying
2976** to promote to an exclusive lock. The first process cannot proceed
2977** because it is blocked by the second and the second process cannot
2978** proceed because it is blocked by the first. If both processes
2979** invoke the busy handlers, neither will make any progress. Therefore,
2980** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
2981** will induce the first process to release its read lock and allow
2982** the second process to proceed.
2983**
2984** ^The default busy callback is NULL.
2985**
2986** ^(There can only be a single busy handler defined for each
2987** [database connection]. Setting a new busy handler clears any
2988** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()]
2989** or evaluating [PRAGMA busy_timeout=N] will change the
2990** busy handler and thus clear any previously set busy handler.
2991**
2992** The busy callback should not take any actions which modify the
2993** database connection that invoked the busy handler. In other words,
2994** the busy handler is not reentrant. Any such actions
2995** result in undefined behavior.
2996**
2997** A busy handler must not close the database connection
2998** or [prepared statement] that invoked the busy handler.
2999*/
3000SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*);
3001
3002/*
3003** CAPI3REF: Set A Busy Timeout
3004** METHOD: sqlite3
3005**
3006** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
3007** for a specified amount of time when a table is locked. ^The handler
3008** will sleep multiple times until at least "ms" milliseconds of sleeping
3009** have accumulated. ^After at least "ms" milliseconds of sleeping,
3010** the handler returns 0 which causes [sqlite3_step()] to return
3011** [SQLITE_BUSY].
3012**
3013** ^Calling this routine with an argument less than or equal to zero
3014** turns off all busy handlers.
3015**
3016** ^(There can only be a single busy handler for a particular
3017** [database connection] at any given moment. If another busy handler
3018** was defined (using [sqlite3_busy_handler()]) prior to calling
3019** this routine, that other busy handler is cleared.)^
3020**
3021** See also: [PRAGMA busy_timeout]
3022*/
3023SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms);
3024
3025/*
3026** CAPI3REF: Set the Setlk Timeout
3027** METHOD: sqlite3
3028**
3029** This routine is only useful in SQLITE_ENABLE_SETLK_TIMEOUT builds. If
3030** the VFS supports blocking locks, it sets the timeout in ms used by
3031** eligible locks taken on wal mode databases by the specified database
3032** handle. In non-SQLITE_ENABLE_SETLK_TIMEOUT builds, or if the VFS does
3033** not support blocking locks, this function is a no-op.
3034**
3035** Passing 0 to this function disables blocking locks altogether. Passing
3036** -1 to this function requests that the VFS blocks for a long time -
3037** indefinitely if possible. The results of passing any other negative value
3038** are undefined.
3039**
3040** Internally, each SQLite database handle store two timeout values - the
3041** busy-timeout (used for rollback mode databases, or if the VFS does not
3042** support blocking locks) and the setlk-timeout (used for blocking locks
3043** on wal-mode databases). The sqlite3_busy_timeout() method sets both
3044** values, this function sets only the setlk-timeout value. Therefore,
3045** to configure separate busy-timeout and setlk-timeout values for a single
3046** database handle, call sqlite3_busy_timeout() followed by this function.
3047**
3048** Whenever the number of connections to a wal mode database falls from
3049** 1 to 0, the last connection takes an exclusive lock on the database,
3050** then checkpoints and deletes the wal file. While it is doing this, any
3051** new connection that tries to read from the database fails with an
3052** SQLITE_BUSY error. Or, if the SQLITE_SETLK_BLOCK_ON_CONNECT flag is
3053** passed to this API, the new connection blocks until the exclusive lock
3054** has been released.
3055*/
3056SQLITE_API int sqlite3_setlk_timeout(sqlite3*, int ms, int flags);
3057
3058/*
3059** CAPI3REF: Flags for sqlite3_setlk_timeout()
3060*/
3061#define SQLITE_SETLK_BLOCK_ON_CONNECT 0x01
3062
3063/*
3064** CAPI3REF: Convenience Routines For Running Queries
3065** METHOD: sqlite3
3066**
3067** This is a legacy interface that is preserved for backwards compatibility.
3068** Use of this interface is not recommended.
3069**
3070** Definition: A <b>result table</b> is memory data structure created by the
3071** [sqlite3_get_table()] interface. A result table records the
3072** complete query results from one or more queries.
3073**
3074** The table conceptually has a number of rows and columns. But
3075** these numbers are not part of the result table itself. These
3076** numbers are obtained separately. Let N be the number of rows
3077** and M be the number of columns.
3078**
3079** A result table is an array of pointers to zero-terminated UTF-8 strings.
3080** There are (N+1)*M elements in the array. The first M pointers point
3081** to zero-terminated strings that contain the names of the columns.
3082** The remaining entries all point to query results. NULL values result
3083** in NULL pointers. All other values are in their UTF-8 zero-terminated
3084** string representation as returned by [sqlite3_column_text()].
3085**
3086** A result table might consist of one or more memory allocations.
3087** It is not safe to pass a result table directly to [sqlite3_free()].
3088** A result table should be deallocated using [sqlite3_free_table()].
3089**
3090** ^(As an example of the result table format, suppose a query result
3091** is as follows:
3092**
3093** <blockquote><pre>
3094** Name | Age
3095** -----------------------
3096** Alice | 43
3097** Bob | 28
3098** Cindy | 21
3099** </pre></blockquote>
3100**
3101** There are two columns (M==2) and three rows (N==3). Thus the
3102** result table has 8 entries. Suppose the result table is stored
3103** in an array named azResult. Then azResult holds this content:
3104**
3105** <blockquote><pre>
3106** azResult[0] = "Name";
3107** azResult[1] = "Age";
3108** azResult[2] = "Alice";
3109** azResult[3] = "43";
3110** azResult[4] = "Bob";
3111** azResult[5] = "28";
3112** azResult[6] = "Cindy";
3113** azResult[7] = "21";
3114** </pre></blockquote>)^
3115**
3116** ^The sqlite3_get_table() function evaluates one or more
3117** semicolon-separated SQL statements in the zero-terminated UTF-8
3118** string of its 2nd parameter and returns a result table to the
3119** pointer given in its 3rd parameter.
3120**
3121** After the application has finished with the result from sqlite3_get_table(),
3122** it must pass the result table pointer to sqlite3_free_table() in order to
3123** release the memory that was malloced. Because of the way the
3124** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
3125** function must not try to call [sqlite3_free()] directly. Only
3126** [sqlite3_free_table()] is able to release the memory properly and safely.
3127**
3128** The sqlite3_get_table() interface is implemented as a wrapper around
3129** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access
3130** to any internal data structures of SQLite. It uses only the public
3131** interface defined here. As a consequence, errors that occur in the
3132** wrapper layer outside of the internal [sqlite3_exec()] call are not
3133** reflected in subsequent calls to [sqlite3_errcode()] or
3134** [sqlite3_errmsg()].
3135*/
3136SQLITE_API int sqlite3_get_table(
3137 sqlite3 *db, /* An open database */
3138 const char *zSql, /* SQL to be evaluated */
3139 char ***pazResult, /* Results of the query */
3140 int *pnRow, /* Number of result rows written here */
3141 int *pnColumn, /* Number of result columns written here */
3142 char **pzErrmsg /* Error msg written here */
3143);
3144SQLITE_API void sqlite3_free_table(char **result);
3145
3146/*
3147** CAPI3REF: Formatted String Printing Functions
3148**
3149** These routines are work-alikes of the "printf()" family of functions
3150** from the standard C library.
3151** These routines understand most of the common formatting options from
3152** the standard library printf()
3153** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]).
3154** See the [built-in printf()] documentation for details.
3155**
3156** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
3157** results into memory obtained from [sqlite3_malloc64()].
3158** The strings returned by these two routines should be
3159** released by [sqlite3_free()]. ^Both routines return a
3160** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough
3161** memory to hold the resulting string.
3162**
3163** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
3164** the standard C library. The result is written into the
3165** buffer supplied as the second parameter whose size is given by
3166** the first parameter. Note that the order of the
3167** first two parameters is reversed from snprintf().)^ This is an
3168** historical accident that cannot be fixed without breaking
3169** backwards compatibility. ^(Note also that sqlite3_snprintf()
3170** returns a pointer to its buffer instead of the number of
3171** characters actually written into the buffer.)^ We admit that
3172** the number of characters written would be a more useful return
3173** value but we cannot change the implementation of sqlite3_snprintf()
3174** now without breaking compatibility.
3175**
3176** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
3177** guarantees that the buffer is always zero-terminated. ^The first
3178** parameter "n" is the total size of the buffer, including space for
3179** the zero terminator. So the longest string that can be completely
3180** written will be n-1 characters.
3181**
3182** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
3183**
3184** See also: [built-in printf()], [printf() SQL function]
3185*/
3186SQLITE_API char *sqlite3_mprintf(const char*,...);
3187SQLITE_API char *sqlite3_vmprintf(const char*, va_list);
3188SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...);
3189SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list);
3190
3191/*
3192** CAPI3REF: Memory Allocation Subsystem
3193**
3194** The SQLite core uses these three routines for all of its own
3195** internal memory allocation needs. "Core" in the previous sentence
3196** does not include operating-system specific [VFS] implementation. The
3197** Windows VFS uses native malloc() and free() for some operations.
3198**
3199** ^The sqlite3_malloc() routine returns a pointer to a block
3200** of memory at least N bytes in length, where N is the parameter.
3201** ^If sqlite3_malloc() is unable to obtain sufficient free
3202** memory, it returns a NULL pointer. ^If the parameter N to
3203** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
3204** a NULL pointer.
3205**
3206** ^The sqlite3_malloc64(N) routine works just like
3207** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead
3208** of a signed 32-bit integer.
3209**
3210** ^Calling sqlite3_free() with a pointer previously returned
3211** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
3212** that it might be reused. ^The sqlite3_free() routine is
3213** a no-op if is called with a NULL pointer. Passing a NULL pointer
3214** to sqlite3_free() is harmless. After being freed, memory
3215** should neither be read nor written. Even reading previously freed
3216** memory might result in a segmentation fault or other severe error.
3217** Memory corruption, a segmentation fault, or other severe error
3218** might result if sqlite3_free() is called with a non-NULL pointer that
3219** was not obtained from sqlite3_malloc() or sqlite3_realloc().
3220**
3221** ^The sqlite3_realloc(X,N) interface attempts to resize a
3222** prior memory allocation X to be at least N bytes.
3223** ^If the X parameter to sqlite3_realloc(X,N)
3224** is a NULL pointer then its behavior is identical to calling
3225** sqlite3_malloc(N).
3226** ^If the N parameter to sqlite3_realloc(X,N) is zero or
3227** negative then the behavior is exactly the same as calling
3228** sqlite3_free(X).
3229** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation
3230** of at least N bytes in size or NULL if insufficient memory is available.
3231** ^If M is the size of the prior allocation, then min(N,M) bytes
3232** of the prior allocation are copied into the beginning of buffer returned
3233** by sqlite3_realloc(X,N) and the prior allocation is freed.
3234** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the
3235** prior allocation is not freed.
3236**
3237** ^The sqlite3_realloc64(X,N) interfaces works the same as
3238** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead
3239** of a 32-bit signed integer.
3240**
3241** ^If X is a memory allocation previously obtained from sqlite3_malloc(),
3242** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then
3243** sqlite3_msize(X) returns the size of that memory allocation in bytes.
3244** ^The value returned by sqlite3_msize(X) might be larger than the number
3245** of bytes requested when X was allocated. ^If X is a NULL pointer then
3246** sqlite3_msize(X) returns zero. If X points to something that is not
3247** the beginning of memory allocation, or if it points to a formerly
3248** valid memory allocation that has now been freed, then the behavior
3249** of sqlite3_msize(X) is undefined and possibly harmful.
3250**
3251** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(),
3252** sqlite3_malloc64(), and sqlite3_realloc64()
3253** is always aligned to at least an 8 byte boundary, or to a
3254** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
3255** option is used.
3256**
3257** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
3258** must be either NULL or else pointers obtained from a prior
3259** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
3260** not yet been released.
3261**
3262** The application must not read or write any part of
3263** a block of memory after it has been released using
3264** [sqlite3_free()] or [sqlite3_realloc()].
3265*/
3266SQLITE_API void *sqlite3_malloc(int);
3267SQLITE_API void *sqlite3_malloc64(sqlite3_uint64);
3268SQLITE_API void *sqlite3_realloc(void*, int);
3269SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64);
3270SQLITE_API void sqlite3_free(void*);
3271SQLITE_API sqlite3_uint64 sqlite3_msize(void*);
3272
3273/*
3274** CAPI3REF: Memory Allocator Statistics
3275**
3276** SQLite provides these two interfaces for reporting on the status
3277** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
3278** routines, which form the built-in memory allocation subsystem.
3279**
3280** ^The [sqlite3_memory_used()] routine returns the number of bytes
3281** of memory currently outstanding (malloced but not freed).
3282** ^The [sqlite3_memory_highwater()] routine returns the maximum
3283** value of [sqlite3_memory_used()] since the high-water mark
3284** was last reset. ^The values returned by [sqlite3_memory_used()] and
3285** [sqlite3_memory_highwater()] include any overhead
3286** added by SQLite in its implementation of [sqlite3_malloc()],
3287** but not overhead added by the any underlying system library
3288** routines that [sqlite3_malloc()] may call.
3289**
3290** ^The memory high-water mark is reset to the current value of
3291** [sqlite3_memory_used()] if and only if the parameter to
3292** [sqlite3_memory_highwater()] is true. ^The value returned
3293** by [sqlite3_memory_highwater(1)] is the high-water mark
3294** prior to the reset.
3295*/
3296SQLITE_API sqlite3_int64 sqlite3_memory_used(void);
3297SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
3298
3299/*
3300** CAPI3REF: Pseudo-Random Number Generator
3301**
3302** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
3303** select random [ROWID | ROWIDs] when inserting new records into a table that
3304** already uses the largest possible [ROWID]. The PRNG is also used for
3305** the built-in random() and randomblob() SQL functions. This interface allows
3306** applications to access the same PRNG for other purposes.
3307**
3308** ^A call to this routine stores N bytes of randomness into buffer P.
3309** ^The P parameter can be a NULL pointer.
3310**
3311** ^If this routine has not been previously called or if the previous
3312** call had N less than one or a NULL pointer for P, then the PRNG is
3313** seeded using randomness obtained from the xRandomness method of
3314** the default [sqlite3_vfs] object.
3315** ^If the previous call to this routine had an N of 1 or more and a
3316** non-NULL P then the pseudo-randomness is generated
3317** internally and without recourse to the [sqlite3_vfs] xRandomness
3318** method.
3319*/
3320SQLITE_API void sqlite3_randomness(int N, void *P);
3321
3322/*
3323** CAPI3REF: Compile-Time Authorization Callbacks
3324** METHOD: sqlite3
3325** KEYWORDS: {authorizer callback}
3326**
3327** ^This routine registers an authorizer callback with a particular
3328** [database connection], supplied in the first argument.
3329** ^The authorizer callback is invoked as SQL statements are being compiled
3330** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
3331** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()],
3332** and [sqlite3_prepare16_v3()]. ^At various
3333** points during the compilation process, as logic is being created
3334** to perform various actions, the authorizer callback is invoked to
3335** see if those actions are allowed. ^The authorizer callback should
3336** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
3337** specific action but allow the SQL statement to continue to be
3338** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
3339** rejected with an error. ^If the authorizer callback returns
3340** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
3341** then the [sqlite3_prepare_v2()] or equivalent call that triggered
3342** the authorizer will fail with an error message.
3343**
3344** When the callback returns [SQLITE_OK], that means the operation
3345** requested is ok. ^When the callback returns [SQLITE_DENY], the
3346** [sqlite3_prepare_v2()] or equivalent call that triggered the
3347** authorizer will fail with an error message explaining that
3348** access is denied.
3349**
3350** ^The first parameter to the authorizer callback is a copy of the third
3351** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
3352** to the callback is an integer [SQLITE_COPY | action code] that specifies
3353** the particular action to be authorized. ^The third through sixth parameters
3354** to the callback are either NULL pointers or zero-terminated strings
3355** that contain additional details about the action to be authorized.
3356** Applications must always be prepared to encounter a NULL pointer in any
3357** of the third through the sixth parameters of the authorization callback.
3358**
3359** ^If the action code is [SQLITE_READ]
3360** and the callback returns [SQLITE_IGNORE] then the
3361** [prepared statement] statement is constructed to substitute
3362** a NULL value in place of the table column that would have
3363** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE]
3364** return can be used to deny an untrusted user access to individual
3365** columns of a table.
3366** ^When a table is referenced by a [SELECT] but no column values are
3367** extracted from that table (for example in a query like
3368** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback
3369** is invoked once for that table with a column name that is an empty string.
3370** ^If the action code is [SQLITE_DELETE] and the callback returns
3371** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
3372** [truncate optimization] is disabled and all rows are deleted individually.
3373**
3374** An authorizer is used when [sqlite3_prepare | preparing]
3375** SQL statements from an untrusted source, to ensure that the SQL statements
3376** do not try to access data they are not allowed to see, or that they do not
3377** try to execute malicious statements that damage the database. For
3378** example, an application may allow a user to enter arbitrary
3379** SQL queries for evaluation by a database. But the application does
3380** not want the user to be able to make arbitrary changes to the
3381** database. An authorizer could then be put in place while the
3382** user-entered SQL is being [sqlite3_prepare | prepared] that
3383** disallows everything except [SELECT] statements.
3384**
3385** Applications that need to process SQL from untrusted sources
3386** might also consider lowering resource limits using [sqlite3_limit()]
3387** and limiting database size using the [max_page_count] [PRAGMA]
3388** in addition to using an authorizer.
3389**
3390** ^(Only a single authorizer can be in place on a database connection
3391** at a time. Each call to sqlite3_set_authorizer overrides the
3392** previous call.)^ ^Disable the authorizer by installing a NULL callback.
3393** The authorizer is disabled by default.
3394**
3395** The authorizer callback must not do anything that will modify
3396** the database connection that invoked the authorizer callback.
3397** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3398** database connections for the meaning of "modify" in this paragraph.
3399**
3400** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
3401** statement might be re-prepared during [sqlite3_step()] due to a
3402** schema change. Hence, the application should ensure that the
3403** correct authorizer callback remains in place during the [sqlite3_step()].
3404**
3405** ^Note that the authorizer callback is invoked only during
3406** [sqlite3_prepare()] or its variants. Authorization is not
3407** performed during statement evaluation in [sqlite3_step()], unless
3408** as stated in the previous paragraph, sqlite3_step() invokes
3409** sqlite3_prepare_v2() to reprepare a statement after a schema change.
3410*/
3411SQLITE_API int sqlite3_set_authorizer(
3412 sqlite3*,
3413 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
3414 void *pUserData
3415);
3416
3417/*
3418** CAPI3REF: Authorizer Return Codes
3419**
3420** The [sqlite3_set_authorizer | authorizer callback function] must
3421** return either [SQLITE_OK] or one of these two constants in order
3422** to signal SQLite whether or not the action is permitted. See the
3423** [sqlite3_set_authorizer | authorizer documentation] for additional
3424** information.
3425**
3426** Note that SQLITE_IGNORE is also used as a [conflict resolution mode]
3427** returned from the [sqlite3_vtab_on_conflict()] interface.
3428*/
3429#define SQLITE_DENY 1 /* Abort the SQL statement with an error */
3430#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */
3431
3432/*
3433** CAPI3REF: Authorizer Action Codes
3434**
3435** The [sqlite3_set_authorizer()] interface registers a callback function
3436** that is invoked to authorize certain SQL statement actions. The
3437** second parameter to the callback is an integer code that specifies
3438** what action is being authorized. These are the integer action codes that
3439** the authorizer callback may be passed.
3440**
3441** These action code values signify what kind of operation is to be
3442** authorized. The 3rd and 4th parameters to the authorization
3443** callback function will be parameters or NULL depending on which of these
3444** codes is used as the second parameter. ^(The 5th parameter to the
3445** authorizer callback is the name of the database ("main", "temp",
3446** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback
3447** is the name of the inner-most trigger or view that is responsible for
3448** the access attempt or NULL if this access attempt is directly from
3449** top-level SQL code.
3450*/
3451/******************************************* 3rd ************ 4th ***********/
3452#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */
3453#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */
3454#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */
3455#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */
3456#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */
3457#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */
3458#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */
3459#define SQLITE_CREATE_VIEW 8 /* View Name NULL */
3460#define SQLITE_DELETE 9 /* Table Name NULL */
3461#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */
3462#define SQLITE_DROP_TABLE 11 /* Table Name NULL */
3463#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */
3464#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */
3465#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */
3466#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */
3467#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */
3468#define SQLITE_DROP_VIEW 17 /* View Name NULL */
3469#define SQLITE_INSERT 18 /* Table Name NULL */
3470#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */
3471#define SQLITE_READ 20 /* Table Name Column Name */
3472#define SQLITE_SELECT 21 /* NULL NULL */
3473#define SQLITE_TRANSACTION 22 /* Operation NULL */
3474#define SQLITE_UPDATE 23 /* Table Name Column Name */
3475#define SQLITE_ATTACH 24 /* Filename NULL */
3476#define SQLITE_DETACH 25 /* Database Name NULL */
3477#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */
3478#define SQLITE_REINDEX 27 /* Index Name NULL */
3479#define SQLITE_ANALYZE 28 /* Table Name NULL */
3480#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */
3481#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */
3482#define SQLITE_FUNCTION 31 /* NULL Function Name */
3483#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */
3484#define SQLITE_COPY 0 /* No longer used */
3485#define SQLITE_RECURSIVE 33 /* NULL NULL */
3486
3487/*
3488** CAPI3REF: Deprecated Tracing And Profiling Functions
3489** DEPRECATED
3490**
3491** These routines are deprecated. Use the [sqlite3_trace_v2()] interface
3492** instead of the routines described here.
3493**
3494** These routines register callback functions that can be used for
3495** tracing and profiling the execution of SQL statements.
3496**
3497** ^The callback function registered by sqlite3_trace() is invoked at
3498** various times when an SQL statement is being run by [sqlite3_step()].
3499** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
3500** SQL statement text as the statement first begins executing.
3501** ^(Additional sqlite3_trace() callbacks might occur
3502** as each triggered subprogram is entered. The callbacks for triggers
3503** contain a UTF-8 SQL comment that identifies the trigger.)^
3504**
3505** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit
3506** the length of [bound parameter] expansion in the output of sqlite3_trace().
3507**
3508** ^The callback function registered by sqlite3_profile() is invoked
3509** as each SQL statement finishes. ^The profile callback contains
3510** the original statement text and an estimate of wall-clock time
3511** of how long that statement took to run. ^The profile callback
3512** time is in units of nanoseconds, however the current implementation
3513** is only capable of millisecond resolution so the six least significant
3514** digits in the time are meaningless. Future versions of SQLite
3515** might provide greater resolution on the profiler callback. Invoking
3516** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the
3517** profile callback.
3518*/
3519SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*,
3520 void(*xTrace)(void*,const char*), void*);
3521SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*,
3522 void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
3523
3524/*
3525** CAPI3REF: SQL Trace Event Codes
3526** KEYWORDS: SQLITE_TRACE
3527**
3528** These constants identify classes of events that can be monitored
3529** using the [sqlite3_trace_v2()] tracing logic. The M argument
3530** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of
3531** the following constants. ^The first argument to the trace callback
3532** is one of the following constants.
3533**
3534** New tracing constants may be added in future releases.
3535**
3536** ^A trace callback has four arguments: xCallback(T,C,P,X).
3537** ^The T argument is one of the integer type codes above.
3538** ^The C argument is a copy of the context pointer passed in as the
3539** fourth argument to [sqlite3_trace_v2()].
3540** The P and X arguments are pointers whose meanings depend on T.
3541**
3542** <dl>
3543** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt>
3544** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement
3545** first begins running and possibly at other times during the
3546** execution of the prepared statement, such as at the start of each
3547** trigger subprogram. ^The P argument is a pointer to the
3548** [prepared statement]. ^The X argument is a pointer to a string which
3549** is the unexpanded SQL text of the prepared statement or an SQL comment
3550** that indicates the invocation of a trigger. ^The callback can compute
3551** the same text that would have been returned by the legacy [sqlite3_trace()]
3552** interface by using the X argument when X begins with "--" and invoking
3553** [sqlite3_expanded_sql(P)] otherwise.
3554**
3555** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt>
3556** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same
3557** information as is provided by the [sqlite3_profile()] callback.
3558** ^The P argument is a pointer to the [prepared statement] and the
3559** X argument points to a 64-bit integer which is approximately
3560** the number of nanoseconds that the prepared statement took to run.
3561** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes.
3562**
3563** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt>
3564** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared
3565** statement generates a single row of result.
3566** ^The P argument is a pointer to the [prepared statement] and the
3567** X argument is unused.
3568**
3569** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt>
3570** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database
3571** connection closes.
3572** ^The P argument is a pointer to the [database connection] object
3573** and the X argument is unused.
3574** </dl>
3575*/
3576#define SQLITE_TRACE_STMT 0x01
3577#define SQLITE_TRACE_PROFILE 0x02
3578#define SQLITE_TRACE_ROW 0x04
3579#define SQLITE_TRACE_CLOSE 0x08
3580
3581/*
3582** CAPI3REF: SQL Trace Hook
3583** METHOD: sqlite3
3584**
3585** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback
3586** function X against [database connection] D, using property mask M
3587** and context pointer P. ^If the X callback is
3588** NULL or if the M mask is zero, then tracing is disabled. The
3589** M argument should be the bitwise OR-ed combination of
3590** zero or more [SQLITE_TRACE] constants.
3591**
3592** ^Each call to either sqlite3_trace(D,X,P) or sqlite3_trace_v2(D,M,X,P)
3593** overrides (cancels) all prior calls to sqlite3_trace(D,X,P) or
3594** sqlite3_trace_v2(D,M,X,P) for the [database connection] D. Each
3595** database connection may have at most one trace callback.
3596**
3597** ^The X callback is invoked whenever any of the events identified by
3598** mask M occur. ^The integer return value from the callback is currently
3599** ignored, though this may change in future releases. Callback
3600** implementations should return zero to ensure future compatibility.
3601**
3602** ^A trace callback is invoked with four arguments: callback(T,C,P,X).
3603** ^The T argument is one of the [SQLITE_TRACE]
3604** constants to indicate why the callback was invoked.
3605** ^The C argument is a copy of the context pointer.
3606** The P and X arguments are pointers whose meanings depend on T.
3607**
3608** The sqlite3_trace_v2() interface is intended to replace the legacy
3609** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which
3610** are deprecated.
3611*/
3612SQLITE_API int sqlite3_trace_v2(
3613 sqlite3*,
3614 unsigned uMask,
3615 int(*xCallback)(unsigned,void*,void*,void*),
3616 void *pCtx
3617);
3618
3619/*
3620** CAPI3REF: Query Progress Callbacks
3621** METHOD: sqlite3
3622**
3623** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
3624** function X to be invoked periodically during long running calls to
3625** [sqlite3_step()] and [sqlite3_prepare()] and similar for
3626** database connection D. An example use for this
3627** interface is to keep a GUI updated during a large query.
3628**
3629** ^The parameter P is passed through as the only parameter to the
3630** callback function X. ^The parameter N is the approximate number of
3631** [virtual machine instructions] that are evaluated between successive
3632** invocations of the callback X. ^If N is less than one then the progress
3633** handler is disabled.
3634**
3635** ^Only a single progress handler may be defined at one time per
3636** [database connection]; setting a new progress handler cancels the
3637** old one. ^Setting parameter X to NULL disables the progress handler.
3638** ^The progress handler is also disabled by setting N to a value less
3639** than 1.
3640**
3641** ^If the progress callback returns non-zero, the operation is
3642** interrupted. This feature can be used to implement a
3643** "Cancel" button on a GUI progress dialog box.
3644**
3645** The progress handler callback must not do anything that will modify
3646** the database connection that invoked the progress handler.
3647** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3648** database connections for the meaning of "modify" in this paragraph.
3649**
3650** The progress handler callback would originally only be invoked from the
3651** bytecode engine. It still might be invoked during [sqlite3_prepare()]
3652** and similar because those routines might force a reparse of the schema
3653** which involves running the bytecode engine. However, beginning with
3654** SQLite version 3.41.0, the progress handler callback might also be
3655** invoked directly from [sqlite3_prepare()] while analyzing and generating
3656** code for complex queries.
3657*/
3658SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
3659
3660/*
3661** CAPI3REF: Opening A New Database Connection
3662** CONSTRUCTOR: sqlite3
3663**
3664** ^These routines open an SQLite database file as specified by the
3665** filename argument. ^The filename argument is interpreted as UTF-8 for
3666** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
3667** order for sqlite3_open16(). ^(A [database connection] handle is usually
3668** returned in *ppDb, even if an error occurs. The only exception is that
3669** if SQLite is unable to allocate memory to hold the [sqlite3] object,
3670** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
3671** object.)^ ^(If the database is opened (and/or created) successfully, then
3672** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The
3673** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
3674** an English language description of the error following a failure of any
3675** of the sqlite3_open() routines.
3676**
3677** ^The default encoding will be UTF-8 for databases created using
3678** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases
3679** created using sqlite3_open16() will be UTF-16 in the native byte order.
3680**
3681** Whether or not an error occurs when it is opened, resources
3682** associated with the [database connection] handle should be released by
3683** passing it to [sqlite3_close()] when it is no longer required.
3684**
3685** The sqlite3_open_v2() interface works like sqlite3_open()
3686** except that it accepts two additional parameters for additional control
3687** over the new database connection. ^(The flags parameter to
3688** sqlite3_open_v2() must include, at a minimum, one of the following
3689** three flag combinations:)^
3690**
3691** <dl>
3692** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
3693** <dd>The database is opened in read-only mode. If the database does
3694** not already exist, an error is returned.</dd>)^
3695**
3696** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
3697** <dd>The database is opened for reading and writing if possible, or
3698** reading only if the file is write protected by the operating
3699** system. In either case the database must already exist, otherwise
3700** an error is returned. For historical reasons, if opening in
3701** read-write mode fails due to OS-level permissions, an attempt is
3702** made to open it in read-only mode. [sqlite3_db_readonly()] can be
3703** used to determine whether the database is actually
3704** read-write.</dd>)^
3705**
3706** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
3707** <dd>The database is opened for reading and writing, and is created if
3708** it does not already exist. This is the behavior that is always used for
3709** sqlite3_open() and sqlite3_open16().</dd>)^
3710** </dl>
3711**
3712** In addition to the required flags, the following optional flags are
3713** also supported:
3714**
3715** <dl>
3716** ^(<dt>[SQLITE_OPEN_URI]</dt>
3717** <dd>The filename can be interpreted as a URI if this flag is set.</dd>)^
3718**
3719** ^(<dt>[SQLITE_OPEN_MEMORY]</dt>
3720** <dd>The database will be opened as an in-memory database. The database
3721** is named by the "filename" argument for the purposes of cache-sharing,
3722** if shared cache mode is enabled, but the "filename" is otherwise ignored.
3723** </dd>)^
3724**
3725** ^(<dt>[SQLITE_OPEN_NOMUTEX]</dt>
3726** <dd>The new database connection will use the "multi-thread"
3727** [threading mode].)^ This means that separate threads are allowed
3728** to use SQLite at the same time, as long as each thread is using
3729** a different [database connection].
3730**
3731** ^(<dt>[SQLITE_OPEN_FULLMUTEX]</dt>
3732** <dd>The new database connection will use the "serialized"
3733** [threading mode].)^ This means the multiple threads can safely
3734** attempt to use the same database connection at the same time.
3735** (Mutexes will block any actual concurrency, but in this mode
3736** there is no harm in trying.)
3737**
3738** ^(<dt>[SQLITE_OPEN_SHAREDCACHE]</dt>
3739** <dd>The database is opened [shared cache] enabled, overriding
3740** the default shared cache setting provided by
3741** [sqlite3_enable_shared_cache()].)^
3742** The [use of shared cache mode is discouraged] and hence shared cache
3743** capabilities may be omitted from many builds of SQLite. In such cases,
3744** this option is a no-op.
3745**
3746** ^(<dt>[SQLITE_OPEN_PRIVATECACHE]</dt>
3747** <dd>The database is opened [shared cache] disabled, overriding
3748** the default shared cache setting provided by
3749** [sqlite3_enable_shared_cache()].)^
3750**
3751** [[OPEN_EXRESCODE]] ^(<dt>[SQLITE_OPEN_EXRESCODE]</dt>
3752** <dd>The database connection comes up in "extended result code mode".
3753** In other words, the database behaves as if
3754** [sqlite3_extended_result_codes(db,1)] were called on the database
3755** connection as soon as the connection is created. In addition to setting
3756** the extended result code mode, this flag also causes [sqlite3_open_v2()]
3757** to return an extended result code.</dd>
3758**
3759** [[OPEN_NOFOLLOW]] ^(<dt>[SQLITE_OPEN_NOFOLLOW]</dt>
3760** <dd>The database filename is not allowed to contain a symbolic link</dd>
3761** </dl>)^
3762**
3763** If the 3rd parameter to sqlite3_open_v2() is not one of the
3764** required combinations shown above optionally combined with other
3765** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits]
3766** then the behavior is undefined. Historic versions of SQLite
3767** have silently ignored surplus bits in the flags parameter to
3768** sqlite3_open_v2(), however that behavior might not be carried through
3769** into future versions of SQLite and so applications should not rely
3770** upon it. Note in particular that the SQLITE_OPEN_EXCLUSIVE flag is a no-op
3771** for sqlite3_open_v2(). The SQLITE_OPEN_EXCLUSIVE does *not* cause
3772** the open to fail if the database already exists. The SQLITE_OPEN_EXCLUSIVE
3773** flag is intended for use by the [sqlite3_vfs|VFS interface] only, and not
3774** by sqlite3_open_v2().
3775**
3776** ^The fourth parameter to sqlite3_open_v2() is the name of the
3777** [sqlite3_vfs] object that defines the operating system interface that
3778** the new database connection should use. ^If the fourth parameter is
3779** a NULL pointer then the default [sqlite3_vfs] object is used.
3780**
3781** ^If the filename is ":memory:", then a private, temporary in-memory database
3782** is created for the connection. ^This in-memory database will vanish when
3783** the database connection is closed. Future versions of SQLite might
3784** make use of additional special filenames that begin with the ":" character.
3785** It is recommended that when a database filename actually does begin with
3786** a ":" character you should prefix the filename with a pathname such as
3787** "./" to avoid ambiguity.
3788**
3789** ^If the filename is an empty string, then a private, temporary
3790** on-disk database will be created. ^This private database will be
3791** automatically deleted as soon as the database connection is closed.
3792**
3793** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
3794**
3795** ^If [URI filename] interpretation is enabled, and the filename argument
3796** begins with "file:", then the filename is interpreted as a URI. ^URI
3797** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
3798** set in the third argument to sqlite3_open_v2(), or if it has
3799** been enabled globally using the [SQLITE_CONFIG_URI] option with the
3800** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
3801** URI filename interpretation is turned off
3802** by default, but future releases of SQLite might enable URI filename
3803** interpretation by default. See "[URI filenames]" for additional
3804** information.
3805**
3806** URI filenames are parsed according to RFC 3986. ^If the URI contains an
3807** authority, then it must be either an empty string or the string
3808** "localhost". ^If the authority is not an empty string or "localhost", an
3809** error is returned to the caller. ^The fragment component of a URI, if
3810** present, is ignored.
3811**
3812** ^SQLite uses the path component of the URI as the name of the disk file
3813** which contains the database. ^If the path begins with a '/' character,
3814** then it is interpreted as an absolute path. ^If the path does not begin
3815** with a '/' (meaning that the authority section is omitted from the URI)
3816** then the path is interpreted as a relative path.
3817** ^(On windows, the first component of an absolute path
3818** is a drive specification (e.g. "C:").)^
3819**
3820** [[core URI query parameters]]
3821** The query component of a URI may contain parameters that are interpreted
3822** either by SQLite itself, or by a [VFS | custom VFS implementation].
3823** SQLite and its built-in [VFSes] interpret the
3824** following query parameters:
3825**
3826** <ul>
3827** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
3828** a VFS object that provides the operating system interface that should
3829** be used to access the database file on disk. ^If this option is set to
3830** an empty string the default VFS object is used. ^Specifying an unknown
3831** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
3832** present, then the VFS specified by the option takes precedence over
3833** the value passed as the fourth parameter to sqlite3_open_v2().
3834**
3835** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw",
3836** "rwc", or "memory". Attempting to set it to any other value is
3837** an error)^.
3838** ^If "ro" is specified, then the database is opened for read-only
3839** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the
3840** third argument to sqlite3_open_v2(). ^If the mode option is set to
3841** "rw", then the database is opened for read-write (but not create)
3842** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had
3843** been set. ^Value "rwc" is equivalent to setting both
3844** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is
3845** set to "memory" then a pure [in-memory database] that never reads
3846** or writes from disk is used. ^It is an error to specify a value for
3847** the mode parameter that is less restrictive than that specified by
3848** the flags passed in the third parameter to sqlite3_open_v2().
3849**
3850** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
3851** "private". ^Setting it to "shared" is equivalent to setting the
3852** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
3853** sqlite3_open_v2(). ^Setting the cache parameter to "private" is
3854** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
3855** ^If sqlite3_open_v2() is used and the "cache" parameter is present in
3856** a URI filename, its value overrides any behavior requested by setting
3857** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
3858**
3859** <li> <b>psow</b>: ^The psow parameter indicates whether or not the
3860** [powersafe overwrite] property does or does not apply to the
3861** storage media on which the database file resides.
3862**
3863** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter
3864** which if set disables file locking in rollback journal modes. This
3865** is useful for accessing a database on a filesystem that does not
3866** support locking. Caution: Database corruption might result if two
3867** or more processes write to the same database and any one of those
3868** processes uses nolock=1.
3869**
3870** <li> <b>immutable</b>: ^The immutable parameter is a boolean query
3871** parameter that indicates that the database file is stored on
3872** read-only media. ^When immutable is set, SQLite assumes that the
3873** database file cannot be changed, even by a process with higher
3874** privilege, and so the database is opened read-only and all locking
3875** and change detection is disabled. Caution: Setting the immutable
3876** property on a database file that does in fact change can result
3877** in incorrect query results and/or [SQLITE_CORRUPT] errors.
3878** See also: [SQLITE_IOCAP_IMMUTABLE].
3879**
3880** </ul>
3881**
3882** ^Specifying an unknown parameter in the query component of a URI is not an
3883** error. Future versions of SQLite might understand additional query
3884** parameters. See "[query parameters with special meaning to SQLite]" for
3885** additional information.
3886**
3887** [[URI filename examples]] <h3>URI filename examples</h3>
3888**
3889** <table border="1" align=center cellpadding=5>
3890** <tr><th> URI filenames <th> Results
3891** <tr><td> file:data.db <td>
3892** Open the file "data.db" in the current directory.
3893** <tr><td> file:/home/fred/data.db<br>
3894** file:///home/fred/data.db <br>
3895** file://localhost/home/fred/data.db <br> <td>
3896** Open the database file "/home/fred/data.db".
3897** <tr><td> file://darkstar/home/fred/data.db <td>
3898** An error. "darkstar" is not a recognized authority.
3899** <tr><td style="white-space:nowrap">
3900** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
3901** <td> Windows only: Open the file "data.db" on fred's desktop on drive
3902** C:. Note that the %20 escaping in this example is not strictly
3903** necessary - space characters can be used literally
3904** in URI filenames.
3905** <tr><td> file:data.db?mode=ro&cache=private <td>
3906** Open file "data.db" in the current directory for read-only access.
3907** Regardless of whether or not shared-cache mode is enabled by
3908** default, use a private cache.
3909** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td>
3910** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile"
3911** that uses dot-files in place of posix advisory locking.
3912** <tr><td> file:data.db?mode=readonly <td>
3913** An error. "readonly" is not a valid option for the "mode" parameter.
3914** Use "ro" instead: "file:data.db?mode=ro".
3915** </table>
3916**
3917** ^URI hexadecimal escape sequences (%HH) are supported within the path and
3918** query components of a URI. A hexadecimal escape sequence consists of a
3919** percent sign - "%" - followed by exactly two hexadecimal digits
3920** specifying an octet value. ^Before the path or query components of a
3921** URI filename are interpreted, they are encoded using UTF-8 and all
3922** hexadecimal escape sequences replaced by a single byte containing the
3923** corresponding octet. If this process generates an invalid UTF-8 encoding,
3924** the results are undefined.
3925**
3926** <b>Note to Windows users:</b> The encoding used for the filename argument
3927** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
3928** codepage is currently defined. Filenames containing international
3929** characters must be converted to UTF-8 prior to passing them into
3930** sqlite3_open() or sqlite3_open_v2().
3931**
3932** <b>Note to Windows Runtime users:</b> The temporary directory must be set
3933** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various
3934** features that require the use of temporary files may fail.
3935**
3936** See also: [sqlite3_temp_directory]
3937*/
3938SQLITE_API int sqlite3_open(
3939 const char *filename, /* Database filename (UTF-8) */
3940 sqlite3 **ppDb /* OUT: SQLite db handle */
3941);
3942SQLITE_API int sqlite3_open16(
3943 const void *filename, /* Database filename (UTF-16) */
3944 sqlite3 **ppDb /* OUT: SQLite db handle */
3945);
3946SQLITE_API int sqlite3_open_v2(
3947 const char *filename, /* Database filename (UTF-8) */
3948 sqlite3 **ppDb, /* OUT: SQLite db handle */
3949 int flags, /* Flags */
3950 const char *zVfs /* Name of VFS module to use */
3951);
3952
3953/*
3954** CAPI3REF: Obtain Values For URI Parameters
3955**
3956** These are utility routines, useful to [VFS|custom VFS implementations],
3957** that check if a database file was a URI that contained a specific query
3958** parameter, and if so obtains the value of that query parameter.
3959**
3960** The first parameter to these interfaces (hereafter referred to
3961** as F) must be one of:
3962** <ul>
3963** <li> A database filename pointer created by the SQLite core and
3964** passed into the xOpen() method of a VFS implementation, or
3965** <li> A filename obtained from [sqlite3_db_filename()], or
3966** <li> A new filename constructed using [sqlite3_create_filename()].
3967** </ul>
3968** If the F parameter is not one of the above, then the behavior is
3969** undefined and probably undesirable. Older versions of SQLite were
3970** more tolerant of invalid F parameters than newer versions.
3971**
3972** If F is a suitable filename (as described in the previous paragraph)
3973** and if P is the name of the query parameter, then
3974** sqlite3_uri_parameter(F,P) returns the value of the P
3975** parameter if it exists or a NULL pointer if P does not appear as a
3976** query parameter on F. If P is a query parameter of F and it
3977** has no explicit value, then sqlite3_uri_parameter(F,P) returns
3978** a pointer to an empty string.
3979**
3980** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean
3981** parameter and returns true (1) or false (0) according to the value
3982** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the
3983** value of query parameter P is one of "yes", "true", or "on" in any
3984** case or if the value begins with a non-zero number. The
3985** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of
3986** query parameter P is one of "no", "false", or "off" in any case or
3987** if the value begins with a numeric zero. If P is not a query
3988** parameter on F or if the value of P does not match any of the
3989** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0).
3990**
3991** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a
3992** 64-bit signed integer and returns that integer, or D if P does not
3993** exist. If the value of P is something other than an integer, then
3994** zero is returned.
3995**
3996** The sqlite3_uri_key(F,N) returns a pointer to the name (not
3997** the value) of the N-th query parameter for filename F, or a NULL
3998** pointer if N is less than zero or greater than the number of query
3999** parameters minus 1. The N value is zero-based so N should be 0 to obtain
4000** the name of the first query parameter, 1 for the second parameter, and
4001** so forth.
4002**
4003** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and
4004** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and
4005** is not a database file pathname pointer that the SQLite core passed
4006** into the xOpen VFS method, then the behavior of this routine is undefined
4007** and probably undesirable.
4008**
4009** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F
4010** parameter can also be the name of a rollback journal file or WAL file
4011** in addition to the main database file. Prior to version 3.31.0, these
4012** routines would only work if F was the name of the main database file.
4013** When the F parameter is the name of the rollback journal or WAL file,
4014** it has access to all the same query parameters as were found on the
4015** main database file.
4016**
4017** See the [URI filename] documentation for additional information.
4018*/
4019SQLITE_API const char *sqlite3_uri_parameter(sqlite3_filename z, const char *zParam);
4020SQLITE_API int sqlite3_uri_boolean(sqlite3_filename z, const char *zParam, int bDefault);
4021SQLITE_API sqlite3_int64 sqlite3_uri_int64(sqlite3_filename, const char*, sqlite3_int64);
4022SQLITE_API const char *sqlite3_uri_key(sqlite3_filename z, int N);
4023
4024/*
4025** CAPI3REF: Translate filenames
4026**
4027** These routines are available to [VFS|custom VFS implementations] for
4028** translating filenames between the main database file, the journal file,
4029** and the WAL file.
4030**
4031** If F is the name of an sqlite database file, journal file, or WAL file
4032** passed by the SQLite core into the VFS, then sqlite3_filename_database(F)
4033** returns the name of the corresponding database file.
4034**
4035** If F is the name of an sqlite database file, journal file, or WAL file
4036** passed by the SQLite core into the VFS, or if F is a database filename
4037** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F)
4038** returns the name of the corresponding rollback journal file.
4039**
4040** If F is the name of an sqlite database file, journal file, or WAL file
4041** that was passed by the SQLite core into the VFS, or if F is a database
4042** filename obtained from [sqlite3_db_filename()], then
4043** sqlite3_filename_wal(F) returns the name of the corresponding
4044** WAL file.
4045**
4046** In all of the above, if F is not the name of a database, journal or WAL
4047** filename passed into the VFS from the SQLite core and F is not the
4048** return value from [sqlite3_db_filename()], then the result is
4049** undefined and is likely a memory access violation.
4050*/
4051SQLITE_API const char *sqlite3_filename_database(sqlite3_filename);
4052SQLITE_API const char *sqlite3_filename_journal(sqlite3_filename);
4053SQLITE_API const char *sqlite3_filename_wal(sqlite3_filename);
4054
4055/*
4056** CAPI3REF: Database File Corresponding To A Journal
4057**
4058** ^If X is the name of a rollback or WAL-mode journal file that is
4059** passed into the xOpen method of [sqlite3_vfs], then
4060** sqlite3_database_file_object(X) returns a pointer to the [sqlite3_file]
4061** object that represents the main database file.
4062**
4063** This routine is intended for use in custom [VFS] implementations
4064** only. It is not a general-purpose interface.
4065** The argument sqlite3_file_object(X) must be a filename pointer that
4066** has been passed into [sqlite3_vfs].xOpen method where the
4067** flags parameter to xOpen contains one of the bits
4068** [SQLITE_OPEN_MAIN_JOURNAL] or [SQLITE_OPEN_WAL]. Any other use
4069** of this routine results in undefined and probably undesirable
4070** behavior.
4071*/
4072SQLITE_API sqlite3_file *sqlite3_database_file_object(const char*);
4073
4074/*
4075** CAPI3REF: Create and Destroy VFS Filenames
4076**
4077** These interfaces are provided for use by [VFS shim] implementations and
4078** are not useful outside of that context.
4079**
4080** The sqlite3_create_filename(D,J,W,N,P) allocates memory to hold a version of
4081** database filename D with corresponding journal file J and WAL file W and
4082** an array P of N URI Key/Value pairs. The result from
4083** sqlite3_create_filename(D,J,W,N,P) is a pointer to a database filename that
4084** is safe to pass to routines like:
4085** <ul>
4086** <li> [sqlite3_uri_parameter()],
4087** <li> [sqlite3_uri_boolean()],
4088** <li> [sqlite3_uri_int64()],
4089** <li> [sqlite3_uri_key()],
4090** <li> [sqlite3_filename_database()],
4091** <li> [sqlite3_filename_journal()], or
4092** <li> [sqlite3_filename_wal()].
4093** </ul>
4094** If a memory allocation error occurs, sqlite3_create_filename() might
4095** return a NULL pointer. The memory obtained from sqlite3_create_filename(X)
4096** must be released by a corresponding call to sqlite3_free_filename(Y).
4097**
4098** The P parameter in sqlite3_create_filename(D,J,W,N,P) should be an array
4099** of 2*N pointers to strings. Each pair of pointers in this array corresponds
4100** to a key and value for a query parameter. The P parameter may be a NULL
4101** pointer if N is zero. None of the 2*N pointers in the P array may be
4102** NULL pointers and key pointers should not be empty strings.
4103** None of the D, J, or W parameters to sqlite3_create_filename(D,J,W,N,P) may
4104** be NULL pointers, though they can be empty strings.
4105**
4106** The sqlite3_free_filename(Y) routine releases a memory allocation
4107** previously obtained from sqlite3_create_filename(). Invoking
4108** sqlite3_free_filename(Y) where Y is a NULL pointer is a harmless no-op.
4109**
4110** If the Y parameter to sqlite3_free_filename(Y) is anything other
4111** than a NULL pointer or a pointer previously acquired from
4112** sqlite3_create_filename(), then bad things such as heap
4113** corruption or segfaults may occur. The value Y should not be
4114** used again after sqlite3_free_filename(Y) has been called. This means
4115** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y,
4116** then the corresponding [sqlite3_module.xClose() method should also be
4117** invoked prior to calling sqlite3_free_filename(Y).
4118*/
4119SQLITE_API sqlite3_filename sqlite3_create_filename(
4120 const char *zDatabase,
4121 const char *zJournal,
4122 const char *zWal,
4123 int nParam,
4124 const char **azParam
4125);
4126SQLITE_API void sqlite3_free_filename(sqlite3_filename);
4127
4128/*
4129** CAPI3REF: Error Codes And Messages
4130** METHOD: sqlite3
4131**
4132** ^If the most recent sqlite3_* API call associated with
4133** [database connection] D failed, then the sqlite3_errcode(D) interface
4134** returns the numeric [result code] or [extended result code] for that
4135** API call.
4136** ^The sqlite3_extended_errcode()
4137** interface is the same except that it always returns the
4138** [extended result code] even when extended result codes are
4139** disabled.
4140**
4141** The values returned by sqlite3_errcode() and/or
4142** sqlite3_extended_errcode() might change with each API call.
4143** Except, there are some interfaces that are guaranteed to never
4144** change the value of the error code. The error-code preserving
4145** interfaces include the following:
4146**
4147** <ul>
4148** <li> sqlite3_errcode()
4149** <li> sqlite3_extended_errcode()
4150** <li> sqlite3_errmsg()
4151** <li> sqlite3_errmsg16()
4152** <li> sqlite3_error_offset()
4153** </ul>
4154**
4155** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
4156** text that describes the error, as either UTF-8 or UTF-16 respectively,
4157** or NULL if no error message is available.
4158** (See how SQLite handles [invalid UTF] for exceptions to this rule.)
4159** ^(Memory to hold the error message string is managed internally.
4160** The application does not need to worry about freeing the result.
4161** However, the error string might be overwritten or deallocated by
4162** subsequent calls to other SQLite interface functions.)^
4163**
4164** ^The sqlite3_errstr(E) interface returns the English-language text
4165** that describes the [result code] E, as UTF-8, or NULL if E is not an
4166** result code for which a text error message is available.
4167** ^(Memory to hold the error message string is managed internally
4168** and must not be freed by the application)^.
4169**
4170** ^If the most recent error references a specific token in the input
4171** SQL, the sqlite3_error_offset() interface returns the byte offset
4172** of the start of that token. ^The byte offset returned by
4173** sqlite3_error_offset() assumes that the input SQL is UTF8.
4174** ^If the most recent error does not reference a specific token in the input
4175** SQL, then the sqlite3_error_offset() function returns -1.
4176**
4177** When the serialized [threading mode] is in use, it might be the
4178** case that a second error occurs on a separate thread in between
4179** the time of the first error and the call to these interfaces.
4180** When that happens, the second error will be reported since these
4181** interfaces always report the most recent result. To avoid
4182** this, each thread can obtain exclusive use of the [database connection] D
4183** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
4184** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
4185** all calls to the interfaces listed here are completed.
4186**
4187** If an interface fails with SQLITE_MISUSE, that means the interface
4188** was invoked incorrectly by the application. In that case, the
4189** error code and message may or may not be set.
4190*/
4191SQLITE_API int sqlite3_errcode(sqlite3 *db);
4192SQLITE_API int sqlite3_extended_errcode(sqlite3 *db);
4193SQLITE_API const char *sqlite3_errmsg(sqlite3*);
4194SQLITE_API const void *sqlite3_errmsg16(sqlite3*);
4195SQLITE_API const char *sqlite3_errstr(int);
4196SQLITE_API int sqlite3_error_offset(sqlite3 *db);
4197
4198/*
4199** CAPI3REF: Prepared Statement Object
4200** KEYWORDS: {prepared statement} {prepared statements}
4201**
4202** An instance of this object represents a single SQL statement that
4203** has been compiled into binary form and is ready to be evaluated.
4204**
4205** Think of each SQL statement as a separate computer program. The
4206** original SQL text is source code. A prepared statement object
4207** is the compiled object code. All SQL must be converted into a
4208** prepared statement before it can be run.
4209**
4210** The life-cycle of a prepared statement object usually goes like this:
4211**
4212** <ol>
4213** <li> Create the prepared statement object using [sqlite3_prepare_v2()].
4214** <li> Bind values to [parameters] using the sqlite3_bind_*()
4215** interfaces.
4216** <li> Run the SQL by calling [sqlite3_step()] one or more times.
4217** <li> Reset the prepared statement using [sqlite3_reset()] then go back
4218** to step 2. Do this zero or more times.
4219** <li> Destroy the object using [sqlite3_finalize()].
4220** </ol>
4221*/
4222typedef struct sqlite3_stmt sqlite3_stmt;
4223
4224/*
4225** CAPI3REF: Run-time Limits
4226** METHOD: sqlite3
4227**
4228** ^(This interface allows the size of various constructs to be limited
4229** on a connection by connection basis. The first parameter is the
4230** [database connection] whose limit is to be set or queried. The
4231** second parameter is one of the [limit categories] that define a
4232** class of constructs to be size limited. The third parameter is the
4233** new limit for that construct.)^
4234**
4235** ^If the new limit is a negative number, the limit is unchanged.
4236** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a
4237** [limits | hard upper bound]
4238** set at compile-time by a C preprocessor macro called
4239** [limits | SQLITE_MAX_<i>NAME</i>].
4240** (The "_LIMIT_" in the name is changed to "_MAX_".))^
4241** ^Attempts to increase a limit above its hard upper bound are
4242** silently truncated to the hard upper bound.
4243**
4244** ^Regardless of whether or not the limit was changed, the
4245** [sqlite3_limit()] interface returns the prior value of the limit.
4246** ^Hence, to find the current value of a limit without changing it,
4247** simply invoke this interface with the third parameter set to -1.
4248**
4249** Run-time limits are intended for use in applications that manage
4250** both their own internal database and also databases that are controlled
4251** by untrusted external sources. An example application might be a
4252** web browser that has its own databases for storing history and
4253** separate databases controlled by JavaScript applications downloaded
4254** off the Internet. The internal databases can be given the
4255** large, default limits. Databases managed by external sources can
4256** be given much smaller limits designed to prevent a denial of service
4257** attack. Developers might also want to use the [sqlite3_set_authorizer()]
4258** interface to further control untrusted SQL. The size of the database
4259** created by an untrusted script can be contained using the
4260** [max_page_count] [PRAGMA].
4261**
4262** New run-time limit categories may be added in future releases.
4263*/
4264SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
4265
4266/*
4267** CAPI3REF: Run-Time Limit Categories
4268** KEYWORDS: {limit category} {*limit categories}
4269**
4270** These constants define various performance limits
4271** that can be lowered at run-time using [sqlite3_limit()].
4272** The synopsis of the meanings of the various limits is shown below.
4273** Additional information is available at [limits | Limits in SQLite].
4274**
4275** <dl>
4276** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
4277** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
4278**
4279** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
4280** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
4281**
4282** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt>
4283** <dd>The maximum number of columns in a table definition or in the
4284** result set of a [SELECT] or the maximum number of columns in an index
4285** or in an ORDER BY or GROUP BY clause.</dd>)^
4286**
4287** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
4288** <dd>The maximum depth of the parse tree on any expression.</dd>)^
4289**
4290** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
4291** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
4292**
4293** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
4294** <dd>The maximum number of instructions in a virtual machine program
4295** used to implement an SQL statement. If [sqlite3_prepare_v2()] or
4296** the equivalent tries to allocate space for more than this many opcodes
4297** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^
4298**
4299** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
4300** <dd>The maximum number of arguments on a function.</dd>)^
4301**
4302** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
4303** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
4304**
4305** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]]
4306** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
4307** <dd>The maximum length of the pattern argument to the [LIKE] or
4308** [GLOB] operators.</dd>)^
4309**
4310** [[SQLITE_LIMIT_VARIABLE_NUMBER]]
4311** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
4312** <dd>The maximum index number of any [parameter] in an SQL statement.)^
4313**
4314** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
4315** <dd>The maximum depth of recursion for triggers.</dd>)^
4316**
4317** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt>
4318** <dd>The maximum number of auxiliary worker threads that a single
4319** [prepared statement] may start.</dd>)^
4320** </dl>
4321*/
4322#define SQLITE_LIMIT_LENGTH 0
4323#define SQLITE_LIMIT_SQL_LENGTH 1
4324#define SQLITE_LIMIT_COLUMN 2
4325#define SQLITE_LIMIT_EXPR_DEPTH 3
4326#define SQLITE_LIMIT_COMPOUND_SELECT 4
4327#define SQLITE_LIMIT_VDBE_OP 5
4328#define SQLITE_LIMIT_FUNCTION_ARG 6
4329#define SQLITE_LIMIT_ATTACHED 7
4330#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8
4331#define SQLITE_LIMIT_VARIABLE_NUMBER 9
4332#define SQLITE_LIMIT_TRIGGER_DEPTH 10
4333#define SQLITE_LIMIT_WORKER_THREADS 11
4334
4335/*
4336** CAPI3REF: Prepare Flags
4337**
4338** These constants define various flags that can be passed into
4339** "prepFlags" parameter of the [sqlite3_prepare_v3()] and
4340** [sqlite3_prepare16_v3()] interfaces.
4341**
4342** New flags may be added in future releases of SQLite.
4343**
4344** <dl>
4345** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt>
4346** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner
4347** that the prepared statement will be retained for a long time and
4348** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()]
4349** and [sqlite3_prepare16_v3()] assume that the prepared statement will
4350** be used just once or at most a few times and then destroyed using
4351** [sqlite3_finalize()] relatively soon. The current implementation acts
4352** on this hint by avoiding the use of [lookaside memory] so as not to
4353** deplete the limited store of lookaside memory. Future versions of
4354** SQLite may act on this hint differently.
4355**
4356** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt>
4357** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used
4358** to be required for any prepared statement that wanted to use the
4359** [sqlite3_normalized_sql()] interface. However, the
4360** [sqlite3_normalized_sql()] interface is now available to all
4361** prepared statements, regardless of whether or not they use this
4362** flag.
4363**
4364** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt>
4365** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler
4366** to return an error (error code SQLITE_ERROR) if the statement uses
4367** any virtual tables.
4368**
4369** [[SQLITE_PREPARE_DONT_LOG]] <dt>SQLITE_PREPARE_DONT_LOG</dt>
4370** <dd>The SQLITE_PREPARE_DONT_LOG flag prevents SQL compiler
4371** errors from being sent to the error log defined by
4372** [SQLITE_CONFIG_LOG]. This can be used, for example, to do test
4373** compiles to see if some SQL syntax is well-formed, without generating
4374** messages on the global error log when it is not. If the test compile
4375** fails, the sqlite3_prepare_v3() call returns the same error indications
4376** with or without this flag; it just omits the call to [sqlite3_log()] that
4377** logs the error.
4378** </dl>
4379*/
4380#define SQLITE_PREPARE_PERSISTENT 0x01
4381#define SQLITE_PREPARE_NORMALIZE 0x02
4382#define SQLITE_PREPARE_NO_VTAB 0x04
4383#define SQLITE_PREPARE_DONT_LOG 0x10
4384
4385/*
4386** CAPI3REF: Compiling An SQL Statement
4387** KEYWORDS: {SQL statement compiler}
4388** METHOD: sqlite3
4389** CONSTRUCTOR: sqlite3_stmt
4390**
4391** To execute an SQL statement, it must first be compiled into a byte-code
4392** program using one of these routines. Or, in other words, these routines
4393** are constructors for the [prepared statement] object.
4394**
4395** The preferred routine to use is [sqlite3_prepare_v2()]. The
4396** [sqlite3_prepare()] interface is legacy and should be avoided.
4397** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used
4398** for special purposes.
4399**
4400** The use of the UTF-8 interfaces is preferred, as SQLite currently
4401** does all parsing using UTF-8. The UTF-16 interfaces are provided
4402** as a convenience. The UTF-16 interfaces work by converting the
4403** input text into UTF-8, then invoking the corresponding UTF-8 interface.
4404**
4405** The first argument, "db", is a [database connection] obtained from a
4406** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
4407** [sqlite3_open16()]. The database connection must not have been closed.
4408**
4409** The second argument, "zSql", is the statement to be compiled, encoded
4410** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(),
4411** and sqlite3_prepare_v3()
4412** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(),
4413** and sqlite3_prepare16_v3() use UTF-16.
4414**
4415** ^If the nByte argument is negative, then zSql is read up to the
4416** first zero terminator. ^If nByte is positive, then it is the maximum
4417** number of bytes read from zSql. When nByte is positive, zSql is read
4418** up to the first zero terminator or until the nByte bytes have been read,
4419** whichever comes first. ^If nByte is zero, then no prepared
4420** statement is generated.
4421** If the caller knows that the supplied string is nul-terminated, then
4422** there is a small performance advantage to passing an nByte parameter that
4423** is the number of bytes in the input string <i>including</i>
4424** the nul-terminator.
4425** Note that nByte measure the length of the input in bytes, not
4426** characters, even for the UTF-16 interfaces.
4427**
4428** ^If pzTail is not NULL then *pzTail is made to point to the first byte
4429** past the end of the first SQL statement in zSql. These routines only
4430** compile the first statement in zSql, so *pzTail is left pointing to
4431** what remains uncompiled.
4432**
4433** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
4434** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set
4435** to NULL. ^If the input text contains no SQL (if the input is an empty
4436** string or a comment) then *ppStmt is set to NULL.
4437** The calling procedure is responsible for deleting the compiled
4438** SQL statement using [sqlite3_finalize()] after it has finished with it.
4439** ppStmt may not be NULL.
4440**
4441** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
4442** otherwise an [error code] is returned.
4443**
4444** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(),
4445** and sqlite3_prepare16_v3() interfaces are recommended for all new programs.
4446** The older interfaces (sqlite3_prepare() and sqlite3_prepare16())
4447** are retained for backwards compatibility, but their use is discouraged.
4448** ^In the "vX" interfaces, the prepared statement
4449** that is returned (the [sqlite3_stmt] object) contains a copy of the
4450** original SQL text. This causes the [sqlite3_step()] interface to
4451** behave differently in three ways:
4452**
4453** <ol>
4454** <li>
4455** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
4456** always used to do, [sqlite3_step()] will automatically recompile the SQL
4457** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY]
4458** retries will occur before sqlite3_step() gives up and returns an error.
4459** </li>
4460**
4461** <li>
4462** ^When an error occurs, [sqlite3_step()] will return one of the detailed
4463** [error codes] or [extended error codes]. ^The legacy behavior was that
4464** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
4465** and the application would have to make a second call to [sqlite3_reset()]
4466** in order to find the underlying cause of the problem. With the "v2" prepare
4467** interfaces, the underlying reason for the error is returned immediately.
4468** </li>
4469**
4470** <li>
4471** ^If the specific value bound to a [parameter | host parameter] in the
4472** WHERE clause might influence the choice of query plan for a statement,
4473** then the statement will be automatically recompiled, as if there had been
4474** a schema change, on the first [sqlite3_step()] call following any change
4475** to the [sqlite3_bind_text | bindings] of that [parameter].
4476** ^The specific value of a WHERE-clause [parameter] might influence the
4477** choice of query plan if the parameter is the left-hand side of a [LIKE]
4478** or [GLOB] operator or if the parameter is compared to an indexed column
4479** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled.
4480** </li>
4481** </ol>
4482**
4483** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having
4484** the extra prepFlags parameter, which is a bit array consisting of zero or
4485** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The
4486** sqlite3_prepare_v2() interface works exactly the same as
4487** sqlite3_prepare_v3() with a zero prepFlags parameter.
4488*/
4489SQLITE_API int sqlite3_prepare(
4490 sqlite3 *db, /* Database handle */
4491 const char *zSql, /* SQL statement, UTF-8 encoded */
4492 int nByte, /* Maximum length of zSql in bytes. */
4493 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4494 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4495);
4496SQLITE_API int sqlite3_prepare_v2(
4497 sqlite3 *db, /* Database handle */
4498 const char *zSql, /* SQL statement, UTF-8 encoded */
4499 int nByte, /* Maximum length of zSql in bytes. */
4500 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4501 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4502);
4503SQLITE_API int sqlite3_prepare_v3(
4504 sqlite3 *db, /* Database handle */
4505 const char *zSql, /* SQL statement, UTF-8 encoded */
4506 int nByte, /* Maximum length of zSql in bytes. */
4507 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
4508 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4509 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4510);
4511SQLITE_API int sqlite3_prepare16(
4512 sqlite3 *db, /* Database handle */
4513 const void *zSql, /* SQL statement, UTF-16 encoded */
4514 int nByte, /* Maximum length of zSql in bytes. */
4515 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4516 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4517);
4518SQLITE_API int sqlite3_prepare16_v2(
4519 sqlite3 *db, /* Database handle */
4520 const void *zSql, /* SQL statement, UTF-16 encoded */
4521 int nByte, /* Maximum length of zSql in bytes. */
4522 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4523 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4524);
4525SQLITE_API int sqlite3_prepare16_v3(
4526 sqlite3 *db, /* Database handle */
4527 const void *zSql, /* SQL statement, UTF-16 encoded */
4528 int nByte, /* Maximum length of zSql in bytes. */
4529 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
4530 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4531 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4532);
4533
4534/*
4535** CAPI3REF: Retrieving Statement SQL
4536** METHOD: sqlite3_stmt
4537**
4538** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8
4539** SQL text used to create [prepared statement] P if P was
4540** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()],
4541** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
4542** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8
4543** string containing the SQL text of prepared statement P with
4544** [bound parameters] expanded.
4545** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8
4546** string containing the normalized SQL text of prepared statement P. The
4547** semantics used to normalize a SQL statement are unspecified and subject
4548** to change. At a minimum, literal values will be replaced with suitable
4549** placeholders.
4550**
4551** ^(For example, if a prepared statement is created using the SQL
4552** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345
4553** and parameter :xyz is unbound, then sqlite3_sql() will return
4554** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql()
4555** will return "SELECT 2345,NULL".)^
4556**
4557** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory
4558** is available to hold the result, or if the result would exceed the
4559** the maximum string length determined by the [SQLITE_LIMIT_LENGTH].
4560**
4561** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of
4562** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time
4563** option causes sqlite3_expanded_sql() to always return NULL.
4564**
4565** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P)
4566** are managed by SQLite and are automatically freed when the prepared
4567** statement is finalized.
4568** ^The string returned by sqlite3_expanded_sql(P), on the other hand,
4569** is obtained from [sqlite3_malloc()] and must be freed by the application
4570** by passing it to [sqlite3_free()].
4571**
4572** ^The sqlite3_normalized_sql() interface is only available if
4573** the [SQLITE_ENABLE_NORMALIZE] compile-time option is defined.
4574*/
4575SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt);
4576SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt);
4577#ifdef SQLITE_ENABLE_NORMALIZE
4578SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt);
4579#endif
4580
4581/*
4582** CAPI3REF: Determine If An SQL Statement Writes The Database
4583** METHOD: sqlite3_stmt
4584**
4585** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
4586** and only if the [prepared statement] X makes no direct changes to
4587** the content of the database file.
4588**
4589** Note that [application-defined SQL functions] or
4590** [virtual tables] might change the database indirectly as a side effect.
4591** ^(For example, if an application defines a function "eval()" that
4592** calls [sqlite3_exec()], then the following SQL statement would
4593** change the database file through side-effects:
4594**
4595** <blockquote><pre>
4596** SELECT eval('DELETE FROM t1') FROM t2;
4597** </pre></blockquote>
4598**
4599** But because the [SELECT] statement does not change the database file
4600** directly, sqlite3_stmt_readonly() would still return true.)^
4601**
4602** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
4603** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
4604** since the statements themselves do not actually modify the database but
4605** rather they control the timing of when other statements modify the
4606** database. ^The [ATTACH] and [DETACH] statements also cause
4607** sqlite3_stmt_readonly() to return true since, while those statements
4608** change the configuration of a database connection, they do not make
4609** changes to the content of the database files on disk.
4610** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since
4611** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and
4612** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so
4613** sqlite3_stmt_readonly() returns false for those commands.
4614**
4615** ^This routine returns false if there is any possibility that the
4616** statement might change the database file. ^A false return does
4617** not guarantee that the statement will change the database file.
4618** ^For example, an UPDATE statement might have a WHERE clause that
4619** makes it a no-op, but the sqlite3_stmt_readonly() result would still
4620** be false. ^Similarly, a CREATE TABLE IF NOT EXISTS statement is a
4621** read-only no-op if the table already exists, but
4622** sqlite3_stmt_readonly() still returns false for such a statement.
4623**
4624** ^If prepared statement X is an [EXPLAIN] or [EXPLAIN QUERY PLAN]
4625** statement, then sqlite3_stmt_readonly(X) returns the same value as
4626** if the EXPLAIN or EXPLAIN QUERY PLAN prefix were omitted.
4627*/
4628SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
4629
4630/*
4631** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement
4632** METHOD: sqlite3_stmt
4633**
4634** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the
4635** prepared statement S is an EXPLAIN statement, or 2 if the
4636** statement S is an EXPLAIN QUERY PLAN.
4637** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is
4638** an ordinary statement or a NULL pointer.
4639*/
4640SQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt);
4641
4642/*
4643** CAPI3REF: Change The EXPLAIN Setting For A Prepared Statement
4644** METHOD: sqlite3_stmt
4645**
4646** The sqlite3_stmt_explain(S,E) interface changes the EXPLAIN
4647** setting for [prepared statement] S. If E is zero, then S becomes
4648** a normal prepared statement. If E is 1, then S behaves as if
4649** its SQL text began with "[EXPLAIN]". If E is 2, then S behaves as if
4650** its SQL text began with "[EXPLAIN QUERY PLAN]".
4651**
4652** Calling sqlite3_stmt_explain(S,E) might cause S to be reprepared.
4653** SQLite tries to avoid a reprepare, but a reprepare might be necessary
4654** on the first transition into EXPLAIN or EXPLAIN QUERY PLAN mode.
4655**
4656** Because of the potential need to reprepare, a call to
4657** sqlite3_stmt_explain(S,E) will fail with SQLITE_ERROR if S cannot be
4658** reprepared because it was created using [sqlite3_prepare()] instead of
4659** the newer [sqlite3_prepare_v2()] or [sqlite3_prepare_v3()] interfaces and
4660** hence has no saved SQL text with which to reprepare.
4661**
4662** Changing the explain setting for a prepared statement does not change
4663** the original SQL text for the statement. Hence, if the SQL text originally
4664** began with EXPLAIN or EXPLAIN QUERY PLAN, but sqlite3_stmt_explain(S,0)
4665** is called to convert the statement into an ordinary statement, the EXPLAIN
4666** or EXPLAIN QUERY PLAN keywords will still appear in the sqlite3_sql(S)
4667** output, even though the statement now acts like a normal SQL statement.
4668**
4669** This routine returns SQLITE_OK if the explain mode is successfully
4670** changed, or an error code if the explain mode could not be changed.
4671** The explain mode cannot be changed while a statement is active.
4672** Hence, it is good practice to call [sqlite3_reset(S)]
4673** immediately prior to calling sqlite3_stmt_explain(S,E).
4674*/
4675SQLITE_API int sqlite3_stmt_explain(sqlite3_stmt *pStmt, int eMode);
4676
4677/*
4678** CAPI3REF: Determine If A Prepared Statement Has Been Reset
4679** METHOD: sqlite3_stmt
4680**
4681** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the
4682** [prepared statement] S has been stepped at least once using
4683** [sqlite3_step(S)] but has neither run to completion (returned
4684** [SQLITE_DONE] from [sqlite3_step(S)]) nor
4685** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S)
4686** interface returns false if S is a NULL pointer. If S is not a
4687** NULL pointer and is not a pointer to a valid [prepared statement]
4688** object, then the behavior is undefined and probably undesirable.
4689**
4690** This interface can be used in combination [sqlite3_next_stmt()]
4691** to locate all prepared statements associated with a database
4692** connection that are in need of being reset. This can be used,
4693** for example, in diagnostic routines to search for prepared
4694** statements that are holding a transaction open.
4695*/
4696SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*);
4697
4698/*
4699** CAPI3REF: Dynamically Typed Value Object
4700** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
4701**
4702** SQLite uses the sqlite3_value object to represent all values
4703** that can be stored in a database table. SQLite uses dynamic typing
4704** for the values it stores. ^Values stored in sqlite3_value objects
4705** can be integers, floating point values, strings, BLOBs, or NULL.
4706**
4707** An sqlite3_value object may be either "protected" or "unprotected".
4708** Some interfaces require a protected sqlite3_value. Other interfaces
4709** will accept either a protected or an unprotected sqlite3_value.
4710** Every interface that accepts sqlite3_value arguments specifies
4711** whether or not it requires a protected sqlite3_value. The
4712** [sqlite3_value_dup()] interface can be used to construct a new
4713** protected sqlite3_value from an unprotected sqlite3_value.
4714**
4715** The terms "protected" and "unprotected" refer to whether or not
4716** a mutex is held. An internal mutex is held for a protected
4717** sqlite3_value object but no mutex is held for an unprotected
4718** sqlite3_value object. If SQLite is compiled to be single-threaded
4719** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
4720** or if SQLite is run in one of reduced mutex modes
4721** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
4722** then there is no distinction between protected and unprotected
4723** sqlite3_value objects and they can be used interchangeably. However,
4724** for maximum code portability it is recommended that applications
4725** still make the distinction between protected and unprotected
4726** sqlite3_value objects even when not strictly required.
4727**
4728** ^The sqlite3_value objects that are passed as parameters into the
4729** implementation of [application-defined SQL functions] are protected.
4730** ^The sqlite3_value objects returned by [sqlite3_vtab_rhs_value()]
4731** are protected.
4732** ^The sqlite3_value object returned by
4733** [sqlite3_column_value()] is unprotected.
4734** Unprotected sqlite3_value objects may only be used as arguments
4735** to [sqlite3_result_value()], [sqlite3_bind_value()], and
4736** [sqlite3_value_dup()].
4737** The [sqlite3_value_blob | sqlite3_value_type()] family of
4738** interfaces require protected sqlite3_value objects.
4739*/
4740typedef struct sqlite3_value sqlite3_value;
4741
4742/*
4743** CAPI3REF: SQL Function Context Object
4744**
4745** The context in which an SQL function executes is stored in an
4746** sqlite3_context object. ^A pointer to an sqlite3_context object
4747** is always first parameter to [application-defined SQL functions].
4748** The application-defined SQL function implementation will pass this
4749** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
4750** [sqlite3_aggregate_context()], [sqlite3_user_data()],
4751** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
4752** and/or [sqlite3_set_auxdata()].
4753*/
4754typedef struct sqlite3_context sqlite3_context;
4755
4756/*
4757** CAPI3REF: Binding Values To Prepared Statements
4758** KEYWORDS: {host parameter} {host parameters} {host parameter name}
4759** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
4760** METHOD: sqlite3_stmt
4761**
4762** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
4763** literals may be replaced by a [parameter] that matches one of the following
4764** templates:
4765**
4766** <ul>
4767** <li> ?
4768** <li> ?NNN
4769** <li> :VVV
4770** <li> @VVV
4771** <li> $VVV
4772** </ul>
4773**
4774** In the templates above, NNN represents an integer literal,
4775** and VVV represents an alphanumeric identifier.)^ ^The values of these
4776** parameters (also called "host parameter names" or "SQL parameters")
4777** can be set using the sqlite3_bind_*() routines defined here.
4778**
4779** ^The first argument to the sqlite3_bind_*() routines is always
4780** a pointer to the [sqlite3_stmt] object returned from
4781** [sqlite3_prepare_v2()] or its variants.
4782**
4783** ^The second argument is the index of the SQL parameter to be set.
4784** ^The leftmost SQL parameter has an index of 1. ^When the same named
4785** SQL parameter is used more than once, second and subsequent
4786** occurrences have the same index as the first occurrence.
4787** ^The index for named parameters can be looked up using the
4788** [sqlite3_bind_parameter_index()] API if desired. ^The index
4789** for "?NNN" parameters is the value of NNN.
4790** ^The NNN value must be between 1 and the [sqlite3_limit()]
4791** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 32766).
4792**
4793** ^The third argument is the value to bind to the parameter.
4794** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16()
4795** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter
4796** is ignored and the end result is the same as sqlite3_bind_null().
4797** ^If the third parameter to sqlite3_bind_text() is not NULL, then
4798** it should be a pointer to well-formed UTF8 text.
4799** ^If the third parameter to sqlite3_bind_text16() is not NULL, then
4800** it should be a pointer to well-formed UTF16 text.
4801** ^If the third parameter to sqlite3_bind_text64() is not NULL, then
4802** it should be a pointer to a well-formed unicode string that is
4803** either UTF8 if the sixth parameter is SQLITE_UTF8, or UTF16
4804** otherwise.
4805**
4806** [[byte-order determination rules]] ^The byte-order of
4807** UTF16 input text is determined by the byte-order mark (BOM, U+FEFF)
4808** found in the first character, which is removed, or in the absence of a BOM
4809** the byte order is the native byte order of the host
4810** machine for sqlite3_bind_text16() or the byte order specified in
4811** the 6th parameter for sqlite3_bind_text64().)^
4812** ^If UTF16 input text contains invalid unicode
4813** characters, then SQLite might change those invalid characters
4814** into the unicode replacement character: U+FFFD.
4815**
4816** ^(In those routines that have a fourth argument, its value is the
4817** number of bytes in the parameter. To be clear: the value is the
4818** number of <u>bytes</u> in the value, not the number of characters.)^
4819** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16()
4820** is negative, then the length of the string is
4821** the number of bytes up to the first zero terminator.
4822** If the fourth parameter to sqlite3_bind_blob() is negative, then
4823** the behavior is undefined.
4824** If a non-negative fourth parameter is provided to sqlite3_bind_text()
4825** or sqlite3_bind_text16() or sqlite3_bind_text64() then
4826** that parameter must be the byte offset
4827** where the NUL terminator would occur assuming the string were NUL
4828** terminated. If any NUL characters occur at byte offsets less than
4829** the value of the fourth parameter then the resulting string value will
4830** contain embedded NULs. The result of expressions involving strings
4831** with embedded NULs is undefined.
4832**
4833** ^The fifth argument to the BLOB and string binding interfaces controls
4834** or indicates the lifetime of the object referenced by the third parameter.
4835** These three options exist:
4836** ^ (1) A destructor to dispose of the BLOB or string after SQLite has finished
4837** with it may be passed. ^It is called to dispose of the BLOB or string even
4838** if the call to the bind API fails, except the destructor is not called if
4839** the third parameter is a NULL pointer or the fourth parameter is negative.
4840** ^ (2) The special constant, [SQLITE_STATIC], may be passed to indicate that
4841** the application remains responsible for disposing of the object. ^In this
4842** case, the object and the provided pointer to it must remain valid until
4843** either the prepared statement is finalized or the same SQL parameter is
4844** bound to something else, whichever occurs sooner.
4845** ^ (3) The constant, [SQLITE_TRANSIENT], may be passed to indicate that the
4846** object is to be copied prior to the return from sqlite3_bind_*(). ^The
4847** object and pointer to it must remain valid until then. ^SQLite will then
4848** manage the lifetime of its private copy.
4849**
4850** ^The sixth argument to sqlite3_bind_text64() must be one of
4851** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]
4852** to specify the encoding of the text in the third parameter. If
4853** the sixth argument to sqlite3_bind_text64() is not one of the
4854** allowed values shown above, or if the text encoding is different
4855** from the encoding specified by the sixth parameter, then the behavior
4856** is undefined.
4857**
4858** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
4859** is filled with zeroes. ^A zeroblob uses a fixed amount of memory
4860** (just an integer to hold its size) while it is being processed.
4861** Zeroblobs are intended to serve as placeholders for BLOBs whose
4862** content is later written using
4863** [sqlite3_blob_open | incremental BLOB I/O] routines.
4864** ^A negative value for the zeroblob results in a zero-length BLOB.
4865**
4866** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in
4867** [prepared statement] S to have an SQL value of NULL, but to also be
4868** associated with the pointer P of type T. ^D is either a NULL pointer or
4869** a pointer to a destructor function for P. ^SQLite will invoke the
4870** destructor D with a single argument of P when it is finished using
4871** P. The T parameter should be a static string, preferably a string
4872** literal. The sqlite3_bind_pointer() routine is part of the
4873** [pointer passing interface] added for SQLite 3.20.0.
4874**
4875** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
4876** for the [prepared statement] or with a prepared statement for which
4877** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
4878** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_()
4879** routine is passed a [prepared statement] that has been finalized, the
4880** result is undefined and probably harmful.
4881**
4882** ^Bindings are not cleared by the [sqlite3_reset()] routine.
4883** ^Unbound parameters are interpreted as NULL.
4884**
4885** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
4886** [error code] if anything goes wrong.
4887** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB
4888** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or
4889** [SQLITE_MAX_LENGTH].
4890** ^[SQLITE_RANGE] is returned if the parameter
4891** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails.
4892**
4893** See also: [sqlite3_bind_parameter_count()],
4894** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
4895*/
4896SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
4897SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64,
4898 void(*)(void*));
4899SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double);
4900SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int);
4901SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
4902SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int);
4903SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*));
4904SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
4905SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64,
4906 void(*)(void*), unsigned char encoding);
4907SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
4908SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*));
4909SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
4910SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64);
4911
4912/*
4913** CAPI3REF: Number Of SQL Parameters
4914** METHOD: sqlite3_stmt
4915**
4916** ^This routine can be used to find the number of [SQL parameters]
4917** in a [prepared statement]. SQL parameters are tokens of the
4918** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
4919** placeholders for values that are [sqlite3_bind_blob | bound]
4920** to the parameters at a later time.
4921**
4922** ^(This routine actually returns the index of the largest (rightmost)
4923** parameter. For all forms except ?NNN, this will correspond to the
4924** number of unique parameters. If parameters of the ?NNN form are used,
4925** there may be gaps in the list.)^
4926**
4927** See also: [sqlite3_bind_blob|sqlite3_bind()],
4928** [sqlite3_bind_parameter_name()], and
4929** [sqlite3_bind_parameter_index()].
4930*/
4931SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);
4932
4933/*
4934** CAPI3REF: Name Of A Host Parameter
4935** METHOD: sqlite3_stmt
4936**
4937** ^The sqlite3_bind_parameter_name(P,N) interface returns
4938** the name of the N-th [SQL parameter] in the [prepared statement] P.
4939** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
4940** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
4941** respectively.
4942** In other words, the initial ":" or "$" or "@" or "?"
4943** is included as part of the name.)^
4944** ^Parameters of the form "?" without a following integer have no name
4945** and are referred to as "nameless" or "anonymous parameters".
4946**
4947** ^The first host parameter has an index of 1, not 0.
4948**
4949** ^If the value N is out of range or if the N-th parameter is
4950** nameless, then NULL is returned. ^The returned string is
4951** always in UTF-8 encoding even if the named parameter was
4952** originally specified as UTF-16 in [sqlite3_prepare16()],
4953** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
4954**
4955** See also: [sqlite3_bind_blob|sqlite3_bind()],
4956** [sqlite3_bind_parameter_count()], and
4957** [sqlite3_bind_parameter_index()].
4958*/
4959SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
4960
4961/*
4962** CAPI3REF: Index Of A Parameter With A Given Name
4963** METHOD: sqlite3_stmt
4964**
4965** ^Return the index of an SQL parameter given its name. ^The
4966** index value returned is suitable for use as the second
4967** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero
4968** is returned if no matching parameter is found. ^The parameter
4969** name must be given in UTF-8 even if the original statement
4970** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or
4971** [sqlite3_prepare16_v3()].
4972**
4973** See also: [sqlite3_bind_blob|sqlite3_bind()],
4974** [sqlite3_bind_parameter_count()], and
4975** [sqlite3_bind_parameter_name()].
4976*/
4977SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
4978
4979/*
4980** CAPI3REF: Reset All Bindings On A Prepared Statement
4981** METHOD: sqlite3_stmt
4982**
4983** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
4984** the [sqlite3_bind_blob | bindings] on a [prepared statement].
4985** ^Use this routine to reset all host parameters to NULL.
4986*/
4987SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);
4988
4989/*
4990** CAPI3REF: Number Of Columns In A Result Set
4991** METHOD: sqlite3_stmt
4992**
4993** ^Return the number of columns in the result set returned by the
4994** [prepared statement]. ^If this routine returns 0, that means the
4995** [prepared statement] returns no data (for example an [UPDATE]).
4996** ^However, just because this routine returns a positive number does not
4997** mean that one or more rows of data will be returned. ^A SELECT statement
4998** will always have a positive sqlite3_column_count() but depending on the
4999** WHERE clause constraints and the table content, it might return no rows.
5000**
5001** See also: [sqlite3_data_count()]
5002*/
5003SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt);
5004
5005/*
5006** CAPI3REF: Column Names In A Result Set
5007** METHOD: sqlite3_stmt
5008**
5009** ^These routines return the name assigned to a particular column
5010** in the result set of a [SELECT] statement. ^The sqlite3_column_name()
5011** interface returns a pointer to a zero-terminated UTF-8 string
5012** and sqlite3_column_name16() returns a pointer to a zero-terminated
5013** UTF-16 string. ^The first parameter is the [prepared statement]
5014** that implements the [SELECT] statement. ^The second parameter is the
5015** column number. ^The leftmost column is number 0.
5016**
5017** ^The returned string pointer is valid until either the [prepared statement]
5018** is destroyed by [sqlite3_finalize()] or until the statement is automatically
5019** reprepared by the first call to [sqlite3_step()] for a particular run
5020** or until the next call to
5021** sqlite3_column_name() or sqlite3_column_name16() on the same column.
5022**
5023** ^If sqlite3_malloc() fails during the processing of either routine
5024** (for example during a conversion from UTF-8 to UTF-16) then a
5025** NULL pointer is returned.
5026**
5027** ^The name of a result column is the value of the "AS" clause for
5028** that column, if there is an AS clause. If there is no AS clause
5029** then the name of the column is unspecified and may change from
5030** one release of SQLite to the next.
5031*/
5032SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N);
5033SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N);
5034
5035/*
5036** CAPI3REF: Source Of Data In A Query Result
5037** METHOD: sqlite3_stmt
5038**
5039** ^These routines provide a means to determine the database, table, and
5040** table column that is the origin of a particular result column in a
5041** [SELECT] statement.
5042** ^The name of the database or table or column can be returned as
5043** either a UTF-8 or UTF-16 string. ^The _database_ routines return
5044** the database name, the _table_ routines return the table name, and
5045** the origin_ routines return the column name.
5046** ^The returned string is valid until the [prepared statement] is destroyed
5047** using [sqlite3_finalize()] or until the statement is automatically
5048** reprepared by the first call to [sqlite3_step()] for a particular run
5049** or until the same information is requested
5050** again in a different encoding.
5051**
5052** ^The names returned are the original un-aliased names of the
5053** database, table, and column.
5054**
5055** ^The first argument to these interfaces is a [prepared statement].
5056** ^These functions return information about the Nth result column returned by
5057** the statement, where N is the second function argument.
5058** ^The left-most column is column 0 for these routines.
5059**
5060** ^If the Nth column returned by the statement is an expression or
5061** subquery and is not a column value, then all of these functions return
5062** NULL. ^These routines might also return NULL if a memory allocation error
5063** occurs. ^Otherwise, they return the name of the attached database, table,
5064** or column that query result column was extracted from.
5065**
5066** ^As with all other SQLite APIs, those whose names end with "16" return
5067** UTF-16 encoded strings and the other functions return UTF-8.
5068**
5069** ^These APIs are only available if the library was compiled with the
5070** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
5071**
5072** If two or more threads call one or more
5073** [sqlite3_column_database_name | column metadata interfaces]
5074** for the same [prepared statement] and result column
5075** at the same time then the results are undefined.
5076*/
5077SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int);
5078SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
5079SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int);
5080SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
5081SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
5082SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
5083
5084/*
5085** CAPI3REF: Declared Datatype Of A Query Result
5086** METHOD: sqlite3_stmt
5087**
5088** ^(The first parameter is a [prepared statement].
5089** If this statement is a [SELECT] statement and the Nth column of the
5090** returned result set of that [SELECT] is a table column (not an
5091** expression or subquery) then the declared type of the table
5092** column is returned.)^ ^If the Nth column of the result set is an
5093** expression or subquery, then a NULL pointer is returned.
5094** ^The returned string is always UTF-8 encoded.
5095**
5096** ^(For example, given the database schema:
5097**
5098** CREATE TABLE t1(c1 VARIANT);
5099**
5100** and the following statement to be compiled:
5101**
5102** SELECT c1 + 1, c1 FROM t1;
5103**
5104** this routine would return the string "VARIANT" for the second result
5105** column (i==1), and a NULL pointer for the first result column (i==0).)^
5106**
5107** ^SQLite uses dynamic run-time typing. ^So just because a column
5108** is declared to contain a particular type does not mean that the
5109** data stored in that column is of the declared type. SQLite is
5110** strongly typed, but the typing is dynamic not static. ^Type
5111** is associated with individual values, not with the containers
5112** used to hold those values.
5113*/
5114SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int);
5115SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
5116
5117/*
5118** CAPI3REF: Evaluate An SQL Statement
5119** METHOD: sqlite3_stmt
5120**
5121** After a [prepared statement] has been prepared using any of
5122** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()],
5123** or [sqlite3_prepare16_v3()] or one of the legacy
5124** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
5125** must be called one or more times to evaluate the statement.
5126**
5127** The details of the behavior of the sqlite3_step() interface depend
5128** on whether the statement was prepared using the newer "vX" interfaces
5129** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()],
5130** [sqlite3_prepare16_v2()] or the older legacy
5131** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the
5132** new "vX" interface is recommended for new applications but the legacy
5133** interface will continue to be supported.
5134**
5135** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
5136** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
5137** ^With the "v2" interface, any of the other [result codes] or
5138** [extended result codes] might be returned as well.
5139**
5140** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
5141** database locks it needs to do its job. ^If the statement is a [COMMIT]
5142** or occurs outside of an explicit transaction, then you can retry the
5143** statement. If the statement is not a [COMMIT] and occurs within an
5144** explicit transaction then you should rollback the transaction before
5145** continuing.
5146**
5147** ^[SQLITE_DONE] means that the statement has finished executing
5148** successfully. sqlite3_step() should not be called again on this virtual
5149** machine without first calling [sqlite3_reset()] to reset the virtual
5150** machine back to its initial state.
5151**
5152** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
5153** is returned each time a new row of data is ready for processing by the
5154** caller. The values may be accessed using the [column access functions].
5155** sqlite3_step() is called again to retrieve the next row of data.
5156**
5157** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
5158** violation) has occurred. sqlite3_step() should not be called again on
5159** the VM. More information may be found by calling [sqlite3_errmsg()].
5160** ^With the legacy interface, a more specific error code (for example,
5161** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
5162** can be obtained by calling [sqlite3_reset()] on the
5163** [prepared statement]. ^In the "v2" interface,
5164** the more specific error code is returned directly by sqlite3_step().
5165**
5166** [SQLITE_MISUSE] means that the this routine was called inappropriately.
5167** Perhaps it was called on a [prepared statement] that has
5168** already been [sqlite3_finalize | finalized] or on one that had
5169** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could
5170** be the case that the same database connection is being used by two or
5171** more threads at the same moment in time.
5172**
5173** For all versions of SQLite up to and including 3.6.23.1, a call to
5174** [sqlite3_reset()] was required after sqlite3_step() returned anything
5175** other than [SQLITE_ROW] before any subsequent invocation of
5176** sqlite3_step(). Failure to reset the prepared statement using
5177** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
5178** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1]),
5179** sqlite3_step() began
5180** calling [sqlite3_reset()] automatically in this circumstance rather
5181** than returning [SQLITE_MISUSE]. This is not considered a compatibility
5182** break because any application that ever receives an SQLITE_MISUSE error
5183** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option
5184** can be used to restore the legacy behavior.
5185**
5186** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
5187** API always returns a generic error code, [SQLITE_ERROR], following any
5188** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call
5189** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
5190** specific [error codes] that better describes the error.
5191** We admit that this is a goofy design. The problem has been fixed
5192** with the "v2" interface. If you prepare all of your SQL statements
5193** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()]
5194** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead
5195** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
5196** then the more specific [error codes] are returned directly
5197** by sqlite3_step(). The use of the "vX" interfaces is recommended.
5198*/
5199SQLITE_API int sqlite3_step(sqlite3_stmt*);
5200
5201/*
5202** CAPI3REF: Number of columns in a result set
5203** METHOD: sqlite3_stmt
5204**
5205** ^The sqlite3_data_count(P) interface returns the number of columns in the
5206** current row of the result set of [prepared statement] P.
5207** ^If prepared statement P does not have results ready to return
5208** (via calls to the [sqlite3_column_int | sqlite3_column()] family of
5209** interfaces) then sqlite3_data_count(P) returns 0.
5210** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.
5211** ^The sqlite3_data_count(P) routine returns 0 if the previous call to
5212** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P)
5213** will return non-zero if previous call to [sqlite3_step](P) returned
5214** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum]
5215** where it always returns zero since each step of that multi-step
5216** pragma returns 0 columns of data.
5217**
5218** See also: [sqlite3_column_count()]
5219*/
5220SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
5221
5222/*
5223** CAPI3REF: Fundamental Datatypes
5224** KEYWORDS: SQLITE_TEXT
5225**
5226** ^(Every value in SQLite has one of five fundamental datatypes:
5227**
5228** <ul>
5229** <li> 64-bit signed integer
5230** <li> 64-bit IEEE floating point number
5231** <li> string
5232** <li> BLOB
5233** <li> NULL
5234** </ul>)^
5235**
5236** These constants are codes for each of those types.
5237**
5238** Note that the SQLITE_TEXT constant was also used in SQLite version 2
5239** for a completely different meaning. Software that links against both
5240** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
5241** SQLITE_TEXT.
5242*/
5243#define SQLITE_INTEGER 1
5244#define SQLITE_FLOAT 2
5245#define SQLITE_BLOB 4
5246#define SQLITE_NULL 5
5247#ifdef SQLITE_TEXT
5248# undef SQLITE_TEXT
5249#else
5250# define SQLITE_TEXT 3
5251#endif
5252#define SQLITE3_TEXT 3
5253
5254/*
5255** CAPI3REF: Result Values From A Query
5256** KEYWORDS: {column access functions}
5257** METHOD: sqlite3_stmt
5258**
5259** <b>Summary:</b>
5260** <blockquote><table border=0 cellpadding=0 cellspacing=0>
5261** <tr><td><b>sqlite3_column_blob</b><td>→<td>BLOB result
5262** <tr><td><b>sqlite3_column_double</b><td>→<td>REAL result
5263** <tr><td><b>sqlite3_column_int</b><td>→<td>32-bit INTEGER result
5264** <tr><td><b>sqlite3_column_int64</b><td>→<td>64-bit INTEGER result
5265** <tr><td><b>sqlite3_column_text</b><td>→<td>UTF-8 TEXT result
5266** <tr><td><b>sqlite3_column_text16</b><td>→<td>UTF-16 TEXT result
5267** <tr><td><b>sqlite3_column_value</b><td>→<td>The result as an
5268** [sqlite3_value|unprotected sqlite3_value] object.
5269** <tr><td> <td> <td>
5270** <tr><td><b>sqlite3_column_bytes</b><td>→<td>Size of a BLOB
5271** or a UTF-8 TEXT result in bytes
5272** <tr><td><b>sqlite3_column_bytes16 </b>
5273** <td>→ <td>Size of UTF-16
5274** TEXT in bytes
5275** <tr><td><b>sqlite3_column_type</b><td>→<td>Default
5276** datatype of the result
5277** </table></blockquote>
5278**
5279** <b>Details:</b>
5280**
5281** ^These routines return information about a single column of the current
5282** result row of a query. ^In every case the first argument is a pointer
5283** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
5284** that was returned from [sqlite3_prepare_v2()] or one of its variants)
5285** and the second argument is the index of the column for which information
5286** should be returned. ^The leftmost column of the result set has the index 0.
5287** ^The number of columns in the result can be determined using
5288** [sqlite3_column_count()].
5289**
5290** If the SQL statement does not currently point to a valid row, or if the
5291** column index is out of range, the result is undefined.
5292** These routines may only be called when the most recent call to
5293** [sqlite3_step()] has returned [SQLITE_ROW] and neither
5294** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
5295** If any of these routines are called after [sqlite3_reset()] or
5296** [sqlite3_finalize()] or after [sqlite3_step()] has returned
5297** something other than [SQLITE_ROW], the results are undefined.
5298** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
5299** are called from a different thread while any of these routines
5300** are pending, then the results are undefined.
5301**
5302** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16)
5303** each return the value of a result column in a specific data format. If
5304** the result column is not initially in the requested format (for example,
5305** if the query returns an integer but the sqlite3_column_text() interface
5306** is used to extract the value) then an automatic type conversion is performed.
5307**
5308** ^The sqlite3_column_type() routine returns the
5309** [SQLITE_INTEGER | datatype code] for the initial data type
5310** of the result column. ^The returned value is one of [SQLITE_INTEGER],
5311** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].
5312** The return value of sqlite3_column_type() can be used to decide which
5313** of the first six interface should be used to extract the column value.
5314** The value returned by sqlite3_column_type() is only meaningful if no
5315** automatic type conversions have occurred for the value in question.
5316** After a type conversion, the result of calling sqlite3_column_type()
5317** is undefined, though harmless. Future
5318** versions of SQLite may change the behavior of sqlite3_column_type()
5319** following a type conversion.
5320**
5321** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes()
5322** or sqlite3_column_bytes16() interfaces can be used to determine the size
5323** of that BLOB or string.
5324**
5325** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
5326** routine returns the number of bytes in that BLOB or string.
5327** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
5328** the string to UTF-8 and then returns the number of bytes.
5329** ^If the result is a numeric value then sqlite3_column_bytes() uses
5330** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
5331** the number of bytes in that string.
5332** ^If the result is NULL, then sqlite3_column_bytes() returns zero.
5333**
5334** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()
5335** routine returns the number of bytes in that BLOB or string.
5336** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts
5337** the string to UTF-16 and then returns the number of bytes.
5338** ^If the result is a numeric value then sqlite3_column_bytes16() uses
5339** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns
5340** the number of bytes in that string.
5341** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.
5342**
5343** ^The values returned by [sqlite3_column_bytes()] and
5344** [sqlite3_column_bytes16()] do not include the zero terminators at the end
5345** of the string. ^For clarity: the values returned by
5346** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of
5347** bytes in the string, not the number of characters.
5348**
5349** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
5350** even empty strings, are always zero-terminated. ^The return
5351** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
5352**
5353** ^Strings returned by sqlite3_column_text16() always have the endianness
5354** which is native to the platform, regardless of the text encoding set
5355** for the database.
5356**
5357** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an
5358** [unprotected sqlite3_value] object. In a multithreaded environment,
5359** an unprotected sqlite3_value object may only be used safely with
5360** [sqlite3_bind_value()] and [sqlite3_result_value()].
5361** If the [unprotected sqlite3_value] object returned by
5362** [sqlite3_column_value()] is used in any other way, including calls
5363** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
5364** or [sqlite3_value_bytes()], the behavior is not threadsafe.
5365** Hence, the sqlite3_column_value() interface
5366** is normally only useful within the implementation of
5367** [application-defined SQL functions] or [virtual tables], not within
5368** top-level application code.
5369**
5370** These routines may attempt to convert the datatype of the result.
5371** ^For example, if the internal representation is FLOAT and a text result
5372** is requested, [sqlite3_snprintf()] is used internally to perform the
5373** conversion automatically. ^(The following table details the conversions
5374** that are applied:
5375**
5376** <blockquote>
5377** <table border="1">
5378** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion
5379**
5380** <tr><td> NULL <td> INTEGER <td> Result is 0
5381** <tr><td> NULL <td> FLOAT <td> Result is 0.0
5382** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer
5383** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer
5384** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float
5385** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer
5386** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT
5387** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER
5388** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float
5389** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB
5390** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER
5391** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL
5392** <tr><td> TEXT <td> BLOB <td> No change
5393** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER
5394** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL
5395** <tr><td> BLOB <td> TEXT <td> [CAST] to TEXT, ensure zero terminator
5396** </table>
5397** </blockquote>)^
5398**
5399** Note that when type conversions occur, pointers returned by prior
5400** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
5401** sqlite3_column_text16() may be invalidated.
5402** Type conversions and pointer invalidations might occur
5403** in the following cases:
5404**
5405** <ul>
5406** <li> The initial content is a BLOB and sqlite3_column_text() or
5407** sqlite3_column_text16() is called. A zero-terminator might
5408** need to be added to the string.</li>
5409** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
5410** sqlite3_column_text16() is called. The content must be converted
5411** to UTF-16.</li>
5412** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
5413** sqlite3_column_text() is called. The content must be converted
5414** to UTF-8.</li>
5415** </ul>
5416**
5417** ^Conversions between UTF-16be and UTF-16le are always done in place and do
5418** not invalidate a prior pointer, though of course the content of the buffer
5419** that the prior pointer references will have been modified. Other kinds
5420** of conversion are done in place when it is possible, but sometimes they
5421** are not possible and in those cases prior pointers are invalidated.
5422**
5423** The safest policy is to invoke these routines
5424** in one of the following ways:
5425**
5426** <ul>
5427** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
5428** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
5429** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
5430** </ul>
5431**
5432** In other words, you should call sqlite3_column_text(),
5433** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
5434** into the desired format, then invoke sqlite3_column_bytes() or
5435** sqlite3_column_bytes16() to find the size of the result. Do not mix calls
5436** to sqlite3_column_text() or sqlite3_column_blob() with calls to
5437** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
5438** with calls to sqlite3_column_bytes().
5439**
5440** ^The pointers returned are valid until a type conversion occurs as
5441** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
5442** [sqlite3_finalize()] is called. ^The memory space used to hold strings
5443** and BLOBs is freed automatically. Do not pass the pointers returned
5444** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
5445** [sqlite3_free()].
5446**
5447** As long as the input parameters are correct, these routines will only
5448** fail if an out-of-memory error occurs during a format conversion.
5449** Only the following subset of interfaces are subject to out-of-memory
5450** errors:
5451**
5452** <ul>
5453** <li> sqlite3_column_blob()
5454** <li> sqlite3_column_text()
5455** <li> sqlite3_column_text16()
5456** <li> sqlite3_column_bytes()
5457** <li> sqlite3_column_bytes16()
5458** </ul>
5459**
5460** If an out-of-memory error occurs, then the return value from these
5461** routines is the same as if the column had contained an SQL NULL value.
5462** Valid SQL NULL returns can be distinguished from out-of-memory errors
5463** by invoking the [sqlite3_errcode()] immediately after the suspect
5464** return value is obtained and before any
5465** other SQLite interface is called on the same [database connection].
5466*/
5467SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
5468SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol);
5469SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol);
5470SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
5471SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
5472SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
5473SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
5474SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
5475SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
5476SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol);
5477
5478/*
5479** CAPI3REF: Destroy A Prepared Statement Object
5480** DESTRUCTOR: sqlite3_stmt
5481**
5482** ^The sqlite3_finalize() function is called to delete a [prepared statement].
5483** ^If the most recent evaluation of the statement encountered no errors
5484** or if the statement is never been evaluated, then sqlite3_finalize() returns
5485** SQLITE_OK. ^If the most recent evaluation of statement S failed, then
5486** sqlite3_finalize(S) returns the appropriate [error code] or
5487** [extended error code].
5488**
5489** ^The sqlite3_finalize(S) routine can be called at any point during
5490** the life cycle of [prepared statement] S:
5491** before statement S is ever evaluated, after
5492** one or more calls to [sqlite3_reset()], or after any call
5493** to [sqlite3_step()] regardless of whether or not the statement has
5494** completed execution.
5495**
5496** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.
5497**
5498** The application must finalize every [prepared statement] in order to avoid
5499** resource leaks. It is a grievous error for the application to try to use
5500** a prepared statement after it has been finalized. Any use of a prepared
5501** statement after it has been finalized can result in undefined and
5502** undesirable behavior such as segfaults and heap corruption.
5503*/
5504SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt);
5505
5506/*
5507** CAPI3REF: Reset A Prepared Statement Object
5508** METHOD: sqlite3_stmt
5509**
5510** The sqlite3_reset() function is called to reset a [prepared statement]
5511** object back to its initial state, ready to be re-executed.
5512** ^Any SQL statement variables that had values bound to them using
5513** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
5514** Use [sqlite3_clear_bindings()] to reset the bindings.
5515**
5516** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
5517** back to the beginning of its program.
5518**
5519** ^The return code from [sqlite3_reset(S)] indicates whether or not
5520** the previous evaluation of prepared statement S completed successfully.
5521** ^If [sqlite3_step(S)] has never before been called on S or if
5522** [sqlite3_step(S)] has not been called since the previous call
5523** to [sqlite3_reset(S)], then [sqlite3_reset(S)] will return
5524** [SQLITE_OK].
5525**
5526** ^If the most recent call to [sqlite3_step(S)] for the
5527** [prepared statement] S indicated an error, then
5528** [sqlite3_reset(S)] returns an appropriate [error code].
5529** ^The [sqlite3_reset(S)] interface might also return an [error code]
5530** if there were no prior errors but the process of resetting
5531** the prepared statement caused a new error. ^For example, if an
5532** [INSERT] statement with a [RETURNING] clause is only stepped one time,
5533** that one call to [sqlite3_step(S)] might return SQLITE_ROW but
5534** the overall statement might still fail and the [sqlite3_reset(S)] call
5535** might return SQLITE_BUSY if locking constraints prevent the
5536** database change from committing. Therefore, it is important that
5537** applications check the return code from [sqlite3_reset(S)] even if
5538** no prior call to [sqlite3_step(S)] indicated a problem.
5539**
5540** ^The [sqlite3_reset(S)] interface does not change the values
5541** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
5542*/
5543SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);
5544
5545
5546/*
5547** CAPI3REF: Create Or Redefine SQL Functions
5548** KEYWORDS: {function creation routines}
5549** METHOD: sqlite3
5550**
5551** ^These functions (collectively known as "function creation routines")
5552** are used to add SQL functions or aggregates or to redefine the behavior
5553** of existing SQL functions or aggregates. The only differences between
5554** the three "sqlite3_create_function*" routines are the text encoding
5555** expected for the second parameter (the name of the function being
5556** created) and the presence or absence of a destructor callback for
5557** the application data pointer. Function sqlite3_create_window_function()
5558** is similar, but allows the user to supply the extra callback functions
5559** needed by [aggregate window functions].
5560**
5561** ^The first parameter is the [database connection] to which the SQL
5562** function is to be added. ^If an application uses more than one database
5563** connection then application-defined SQL functions must be added
5564** to each database connection separately.
5565**
5566** ^The second parameter is the name of the SQL function to be created or
5567** redefined. ^The length of the name is limited to 255 bytes in a UTF-8
5568** representation, exclusive of the zero-terminator. ^Note that the name
5569** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.
5570** ^Any attempt to create a function with a longer name
5571** will result in [SQLITE_MISUSE] being returned.
5572**
5573** ^The third parameter (nArg)
5574** is the number of arguments that the SQL function or
5575** aggregate takes. ^If this parameter is -1, then the SQL function or
5576** aggregate may take any number of arguments between 0 and the limit
5577** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third
5578** parameter is less than -1 or greater than 127 then the behavior is
5579** undefined.
5580**
5581** ^The fourth parameter, eTextRep, specifies what
5582** [SQLITE_UTF8 | text encoding] this SQL function prefers for
5583** its parameters. The application should set this parameter to
5584** [SQLITE_UTF16LE] if the function implementation invokes
5585** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the
5586** implementation invokes [sqlite3_value_text16be()] on an input, or
5587** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8]
5588** otherwise. ^The same SQL function may be registered multiple times using
5589** different preferred text encodings, with different implementations for
5590** each encoding.
5591** ^When multiple implementations of the same function are available, SQLite
5592** will pick the one that involves the least amount of data conversion.
5593**
5594** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC]
5595** to signal that the function will always return the same result given
5596** the same inputs within a single SQL statement. Most SQL functions are
5597** deterministic. The built-in [random()] SQL function is an example of a
5598** function that is not deterministic. The SQLite query planner is able to
5599** perform additional optimizations on deterministic functions, so use
5600** of the [SQLITE_DETERMINISTIC] flag is recommended where possible.
5601**
5602** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY]
5603** flag, which if present prevents the function from being invoked from
5604** within VIEWs, TRIGGERs, CHECK constraints, generated column expressions,
5605** index expressions, or the WHERE clause of partial indexes.
5606**
5607** For best security, the [SQLITE_DIRECTONLY] flag is recommended for
5608** all application-defined SQL functions that do not need to be
5609** used inside of triggers, views, CHECK constraints, or other elements of
5610** the database schema. This flag is especially recommended for SQL
5611** functions that have side effects or reveal internal application state.
5612** Without this flag, an attacker might be able to modify the schema of
5613** a database file to include invocations of the function with parameters
5614** chosen by the attacker, which the application will then execute when
5615** the database file is opened and read.
5616**
5617** ^(The fifth parameter is an arbitrary pointer. The implementation of the
5618** function can gain access to this pointer using [sqlite3_user_data()].)^
5619**
5620** ^The sixth, seventh and eighth parameters passed to the three
5621** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are
5622** pointers to C-language functions that implement the SQL function or
5623** aggregate. ^A scalar SQL function requires an implementation of the xFunc
5624** callback only; NULL pointers must be passed as the xStep and xFinal
5625** parameters. ^An aggregate SQL function requires an implementation of xStep
5626** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
5627** SQL function or aggregate, pass NULL pointers for all three function
5628** callbacks.
5629**
5630** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue
5631** and xInverse) passed to sqlite3_create_window_function are pointers to
5632** C-language callbacks that implement the new function. xStep and xFinal
5633** must both be non-NULL. xValue and xInverse may either both be NULL, in
5634** which case a regular aggregate function is created, or must both be
5635** non-NULL, in which case the new function may be used as either an aggregate
5636** or aggregate window function. More details regarding the implementation
5637** of aggregate window functions are
5638** [user-defined window functions|available here].
5639**
5640** ^(If the final parameter to sqlite3_create_function_v2() or
5641** sqlite3_create_window_function() is not NULL, then it is the destructor for
5642** the application data pointer. The destructor is invoked when the function
5643** is deleted, either by being overloaded or when the database connection
5644** closes.)^ ^The destructor is also invoked if the call to
5645** sqlite3_create_function_v2() fails. ^When the destructor callback is
5646** invoked, it is passed a single argument which is a copy of the application
5647** data pointer which was the fifth parameter to sqlite3_create_function_v2().
5648**
5649** ^It is permitted to register multiple implementations of the same
5650** functions with the same name but with either differing numbers of
5651** arguments or differing preferred text encodings. ^SQLite will use
5652** the implementation that most closely matches the way in which the
5653** SQL function is used. ^A function implementation with a non-negative
5654** nArg parameter is a better match than a function implementation with
5655** a negative nArg. ^A function where the preferred text encoding
5656** matches the database encoding is a better
5657** match than a function where the encoding is different.
5658** ^A function where the encoding difference is between UTF16le and UTF16be
5659** is a closer match than a function where the encoding difference is
5660** between UTF8 and UTF16.
5661**
5662** ^Built-in functions may be overloaded by new application-defined functions.
5663**
5664** ^An application-defined function is permitted to call other
5665** SQLite interfaces. However, such calls must not
5666** close the database connection nor finalize or reset the prepared
5667** statement in which the function is running.
5668*/
5669SQLITE_API int sqlite3_create_function(
5670 sqlite3 *db,
5671 const char *zFunctionName,
5672 int nArg,
5673 int eTextRep,
5674 void *pApp,
5675 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5676 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5677 void (*xFinal)(sqlite3_context*)
5678);
5679SQLITE_API int sqlite3_create_function16(
5680 sqlite3 *db,
5681 const void *zFunctionName,
5682 int nArg,
5683 int eTextRep,
5684 void *pApp,
5685 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5686 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5687 void (*xFinal)(sqlite3_context*)
5688);
5689SQLITE_API int sqlite3_create_function_v2(
5690 sqlite3 *db,
5691 const char *zFunctionName,
5692 int nArg,
5693 int eTextRep,
5694 void *pApp,
5695 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5696 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5697 void (*xFinal)(sqlite3_context*),
5698 void(*xDestroy)(void*)
5699);
5700SQLITE_API int sqlite3_create_window_function(
5701 sqlite3 *db,
5702 const char *zFunctionName,
5703 int nArg,
5704 int eTextRep,
5705 void *pApp,
5706 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5707 void (*xFinal)(sqlite3_context*),
5708 void (*xValue)(sqlite3_context*),
5709 void (*xInverse)(sqlite3_context*,int,sqlite3_value**),
5710 void(*xDestroy)(void*)
5711);
5712
5713/*
5714** CAPI3REF: Text Encodings
5715**
5716** These constant define integer codes that represent the various
5717** text encodings supported by SQLite.
5718*/
5719#define SQLITE_UTF8 1 /* IMP: R-37514-35566 */
5720#define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */
5721#define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */
5722#define SQLITE_UTF16 4 /* Use native byte order */
5723#define SQLITE_ANY 5 /* Deprecated */
5724#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */
5725
5726/*
5727** CAPI3REF: Function Flags
5728**
5729** These constants may be ORed together with the
5730** [SQLITE_UTF8 | preferred text encoding] as the fourth argument
5731** to [sqlite3_create_function()], [sqlite3_create_function16()], or
5732** [sqlite3_create_function_v2()].
5733**
5734** <dl>
5735** [[SQLITE_DETERMINISTIC]] <dt>SQLITE_DETERMINISTIC</dt><dd>
5736** The SQLITE_DETERMINISTIC flag means that the new function always gives
5737** the same output when the input parameters are the same.
5738** The [abs|abs() function] is deterministic, for example, but
5739** [randomblob|randomblob()] is not. Functions must
5740** be deterministic in order to be used in certain contexts such as
5741** with the WHERE clause of [partial indexes] or in [generated columns].
5742** SQLite might also optimize deterministic functions by factoring them
5743** out of inner loops.
5744** </dd>
5745**
5746** [[SQLITE_DIRECTONLY]] <dt>SQLITE_DIRECTONLY</dt><dd>
5747** The SQLITE_DIRECTONLY flag means that the function may only be invoked
5748** from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in
5749** schema structures such as [CHECK constraints], [DEFAULT clauses],
5750** [expression indexes], [partial indexes], or [generated columns].
5751** <p>
5752** The SQLITE_DIRECTONLY flag is recommended for any
5753** [application-defined SQL function]
5754** that has side-effects or that could potentially leak sensitive information.
5755** This will prevent attacks in which an application is tricked
5756** into using a database file that has had its schema surreptitiously
5757** modified to invoke the application-defined function in ways that are
5758** harmful.
5759** <p>
5760** Some people say it is good practice to set SQLITE_DIRECTONLY on all
5761** [application-defined SQL functions], regardless of whether or not they
5762** are security sensitive, as doing so prevents those functions from being used
5763** inside of the database schema, and thus ensures that the database
5764** can be inspected and modified using generic tools (such as the [CLI])
5765** that do not have access to the application-defined functions.
5766** </dd>
5767**
5768** [[SQLITE_INNOCUOUS]] <dt>SQLITE_INNOCUOUS</dt><dd>
5769** The SQLITE_INNOCUOUS flag means that the function is unlikely
5770** to cause problems even if misused. An innocuous function should have
5771** no side effects and should not depend on any values other than its
5772** input parameters. The [abs|abs() function] is an example of an
5773** innocuous function.
5774** The [load_extension() SQL function] is not innocuous because of its
5775** side effects.
5776** <p> SQLITE_INNOCUOUS is similar to SQLITE_DETERMINISTIC, but is not
5777** exactly the same. The [random|random() function] is an example of a
5778** function that is innocuous but not deterministic.
5779** <p>Some heightened security settings
5780** ([SQLITE_DBCONFIG_TRUSTED_SCHEMA] and [PRAGMA trusted_schema=OFF])
5781** disable the use of SQL functions inside views and triggers and in
5782** schema structures such as [CHECK constraints], [DEFAULT clauses],
5783** [expression indexes], [partial indexes], and [generated columns] unless
5784** the function is tagged with SQLITE_INNOCUOUS. Most built-in functions
5785** are innocuous. Developers are advised to avoid using the
5786** SQLITE_INNOCUOUS flag for application-defined functions unless the
5787** function has been carefully audited and found to be free of potentially
5788** security-adverse side-effects and information-leaks.
5789** </dd>
5790**
5791** [[SQLITE_SUBTYPE]] <dt>SQLITE_SUBTYPE</dt><dd>
5792** The SQLITE_SUBTYPE flag indicates to SQLite that a function might call
5793** [sqlite3_value_subtype()] to inspect the sub-types of its arguments.
5794** This flag instructs SQLite to omit some corner-case optimizations that
5795** might disrupt the operation of the [sqlite3_value_subtype()] function,
5796** causing it to return zero rather than the correct subtype().
5797** All SQL functions that invoke [sqlite3_value_subtype()] should have this
5798** property. If the SQLITE_SUBTYPE property is omitted, then the return
5799** value from [sqlite3_value_subtype()] might sometimes be zero even though
5800** a non-zero subtype was specified by the function argument expression.
5801**
5802** [[SQLITE_RESULT_SUBTYPE]] <dt>SQLITE_RESULT_SUBTYPE</dt><dd>
5803** The SQLITE_RESULT_SUBTYPE flag indicates to SQLite that a function might call
5804** [sqlite3_result_subtype()] to cause a sub-type to be associated with its
5805** result.
5806** Every function that invokes [sqlite3_result_subtype()] should have this
5807** property. If it does not, then the call to [sqlite3_result_subtype()]
5808** might become a no-op if the function is used as term in an
5809** [expression index]. On the other hand, SQL functions that never invoke
5810** [sqlite3_result_subtype()] should avoid setting this property, as the
5811** purpose of this property is to disable certain optimizations that are
5812** incompatible with subtypes.
5813**
5814** [[SQLITE_SELFORDER1]] <dt>SQLITE_SELFORDER1</dt><dd>
5815** The SQLITE_SELFORDER1 flag indicates that the function is an aggregate
5816** that internally orders the values provided to the first argument. The
5817** ordered-set aggregate SQL notation with a single ORDER BY term can be
5818** used to invoke this function. If the ordered-set aggregate notation is
5819** used on a function that lacks this flag, then an error is raised. Note
5820** that the ordered-set aggregate syntax is only available if SQLite is
5821** built using the -DSQLITE_ENABLE_ORDERED_SET_AGGREGATES compile-time option.
5822** </dd>
5823** </dl>
5824*/
5825#define SQLITE_DETERMINISTIC 0x000000800
5826#define SQLITE_DIRECTONLY 0x000080000
5827#define SQLITE_SUBTYPE 0x000100000
5828#define SQLITE_INNOCUOUS 0x000200000
5829#define SQLITE_RESULT_SUBTYPE 0x001000000
5830#define SQLITE_SELFORDER1 0x002000000
5831
5832/*
5833** CAPI3REF: Deprecated Functions
5834** DEPRECATED
5835**
5836** These functions are [deprecated]. In order to maintain
5837** backwards compatibility with older code, these functions continue
5838** to be supported. However, new applications should avoid
5839** the use of these functions. To encourage programmers to avoid
5840** these functions, we will not explain what they do.
5841*/
5842#ifndef SQLITE_OMIT_DEPRECATED
5843SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*);
5844SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);
5845SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
5846SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void);
5847SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);
5848SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),
5849 void*,sqlite3_int64);
5850#endif
5851
5852/*
5853** CAPI3REF: Obtaining SQL Values
5854** METHOD: sqlite3_value
5855**
5856** <b>Summary:</b>
5857** <blockquote><table border=0 cellpadding=0 cellspacing=0>
5858** <tr><td><b>sqlite3_value_blob</b><td>→<td>BLOB value
5859** <tr><td><b>sqlite3_value_double</b><td>→<td>REAL value
5860** <tr><td><b>sqlite3_value_int</b><td>→<td>32-bit INTEGER value
5861** <tr><td><b>sqlite3_value_int64</b><td>→<td>64-bit INTEGER value
5862** <tr><td><b>sqlite3_value_pointer</b><td>→<td>Pointer value
5863** <tr><td><b>sqlite3_value_text</b><td>→<td>UTF-8 TEXT value
5864** <tr><td><b>sqlite3_value_text16</b><td>→<td>UTF-16 TEXT value in
5865** the native byteorder
5866** <tr><td><b>sqlite3_value_text16be</b><td>→<td>UTF-16be TEXT value
5867** <tr><td><b>sqlite3_value_text16le</b><td>→<td>UTF-16le TEXT value
5868** <tr><td> <td> <td>
5869** <tr><td><b>sqlite3_value_bytes</b><td>→<td>Size of a BLOB
5870** or a UTF-8 TEXT in bytes
5871** <tr><td><b>sqlite3_value_bytes16 </b>
5872** <td>→ <td>Size of UTF-16
5873** TEXT in bytes
5874** <tr><td><b>sqlite3_value_type</b><td>→<td>Default
5875** datatype of the value
5876** <tr><td><b>sqlite3_value_numeric_type </b>
5877** <td>→ <td>Best numeric datatype of the value
5878** <tr><td><b>sqlite3_value_nochange </b>
5879** <td>→ <td>True if the column is unchanged in an UPDATE
5880** against a virtual table.
5881** <tr><td><b>sqlite3_value_frombind </b>
5882** <td>→ <td>True if value originated from a [bound parameter]
5883** </table></blockquote>
5884**
5885** <b>Details:</b>
5886**
5887** These routines extract type, size, and content information from
5888** [protected sqlite3_value] objects. Protected sqlite3_value objects
5889** are used to pass parameter information into the functions that
5890** implement [application-defined SQL functions] and [virtual tables].
5891**
5892** These routines work only with [protected sqlite3_value] objects.
5893** Any attempt to use these routines on an [unprotected sqlite3_value]
5894** is not threadsafe.
5895**
5896** ^These routines work just like the corresponding [column access functions]
5897** except that these routines take a single [protected sqlite3_value] object
5898** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
5899**
5900** ^The sqlite3_value_text16() interface extracts a UTF-16 string
5901** in the native byte-order of the host machine. ^The
5902** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
5903** extract UTF-16 strings as big-endian and little-endian respectively.
5904**
5905** ^If [sqlite3_value] object V was initialized
5906** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)]
5907** and if X and Y are strings that compare equal according to strcmp(X,Y),
5908** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise,
5909** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer()
5910** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
5911**
5912** ^(The sqlite3_value_type(V) interface returns the
5913** [SQLITE_INTEGER | datatype code] for the initial datatype of the
5914** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER],
5915** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^
5916** Other interfaces might change the datatype for an sqlite3_value object.
5917** For example, if the datatype is initially SQLITE_INTEGER and
5918** sqlite3_value_text(V) is called to extract a text value for that
5919** integer, then subsequent calls to sqlite3_value_type(V) might return
5920** SQLITE_TEXT. Whether or not a persistent internal datatype conversion
5921** occurs is undefined and may change from one release of SQLite to the next.
5922**
5923** ^(The sqlite3_value_numeric_type() interface attempts to apply
5924** numeric affinity to the value. This means that an attempt is
5925** made to convert the value to an integer or floating point. If
5926** such a conversion is possible without loss of information (in other
5927** words, if the value is a string that looks like a number)
5928** then the conversion is performed. Otherwise no conversion occurs.
5929** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
5930**
5931** ^Within the [xUpdate] method of a [virtual table], the
5932** sqlite3_value_nochange(X) interface returns true if and only if
5933** the column corresponding to X is unchanged by the UPDATE operation
5934** that the xUpdate method call was invoked to implement and if
5935** and the prior [xColumn] method call that was invoked to extracted
5936** the value for that column returned without setting a result (probably
5937** because it queried [sqlite3_vtab_nochange()] and found that the column
5938** was unchanging). ^Within an [xUpdate] method, any value for which
5939** sqlite3_value_nochange(X) is true will in all other respects appear
5940** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other
5941** than within an [xUpdate] method call for an UPDATE statement, then
5942** the return value is arbitrary and meaningless.
5943**
5944** ^The sqlite3_value_frombind(X) interface returns non-zero if the
5945** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()]
5946** interfaces. ^If X comes from an SQL literal value, or a table column,
5947** or an expression, then sqlite3_value_frombind(X) returns zero.
5948**
5949** Please pay particular attention to the fact that the pointer returned
5950** from [sqlite3_value_blob()], [sqlite3_value_text()], or
5951** [sqlite3_value_text16()] can be invalidated by a subsequent call to
5952** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
5953** or [sqlite3_value_text16()].
5954**
5955** These routines must be called from the same thread as
5956** the SQL function that supplied the [sqlite3_value*] parameters.
5957**
5958** As long as the input parameter is correct, these routines can only
5959** fail if an out-of-memory error occurs during a format conversion.
5960** Only the following subset of interfaces are subject to out-of-memory
5961** errors:
5962**
5963** <ul>
5964** <li> sqlite3_value_blob()
5965** <li> sqlite3_value_text()
5966** <li> sqlite3_value_text16()
5967** <li> sqlite3_value_text16le()
5968** <li> sqlite3_value_text16be()
5969** <li> sqlite3_value_bytes()
5970** <li> sqlite3_value_bytes16()
5971** </ul>
5972**
5973** If an out-of-memory error occurs, then the return value from these
5974** routines is the same as if the column had contained an SQL NULL value.
5975** Valid SQL NULL returns can be distinguished from out-of-memory errors
5976** by invoking the [sqlite3_errcode()] immediately after the suspect
5977** return value is obtained and before any
5978** other SQLite interface is called on the same [database connection].
5979*/
5980SQLITE_API const void *sqlite3_value_blob(sqlite3_value*);
5981SQLITE_API double sqlite3_value_double(sqlite3_value*);
5982SQLITE_API int sqlite3_value_int(sqlite3_value*);
5983SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
5984SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*);
5985SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*);
5986SQLITE_API const void *sqlite3_value_text16(sqlite3_value*);
5987SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*);
5988SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*);
5989SQLITE_API int sqlite3_value_bytes(sqlite3_value*);
5990SQLITE_API int sqlite3_value_bytes16(sqlite3_value*);
5991SQLITE_API int sqlite3_value_type(sqlite3_value*);
5992SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*);
5993SQLITE_API int sqlite3_value_nochange(sqlite3_value*);
5994SQLITE_API int sqlite3_value_frombind(sqlite3_value*);
5995
5996/*
5997** CAPI3REF: Report the internal text encoding state of an sqlite3_value object
5998** METHOD: sqlite3_value
5999**
6000** ^(The sqlite3_value_encoding(X) interface returns one of [SQLITE_UTF8],
6001** [SQLITE_UTF16BE], or [SQLITE_UTF16LE] according to the current text encoding
6002** of the value X, assuming that X has type TEXT.)^ If sqlite3_value_type(X)
6003** returns something other than SQLITE_TEXT, then the return value from
6004** sqlite3_value_encoding(X) is meaningless. ^Calls to
6005** [sqlite3_value_text(X)], [sqlite3_value_text16(X)], [sqlite3_value_text16be(X)],
6006** [sqlite3_value_text16le(X)], [sqlite3_value_bytes(X)], or
6007** [sqlite3_value_bytes16(X)] might change the encoding of the value X and
6008** thus change the return from subsequent calls to sqlite3_value_encoding(X).
6009**
6010** This routine is intended for used by applications that test and validate
6011** the SQLite implementation. This routine is inquiring about the opaque
6012** internal state of an [sqlite3_value] object. Ordinary applications should
6013** not need to know what the internal state of an sqlite3_value object is and
6014** hence should not need to use this interface.
6015*/
6016SQLITE_API int sqlite3_value_encoding(sqlite3_value*);
6017
6018/*
6019** CAPI3REF: Finding The Subtype Of SQL Values
6020** METHOD: sqlite3_value
6021**
6022** The sqlite3_value_subtype(V) function returns the subtype for
6023** an [application-defined SQL function] argument V. The subtype
6024** information can be used to pass a limited amount of context from
6025** one SQL function to another. Use the [sqlite3_result_subtype()]
6026** routine to set the subtype for the return value of an SQL function.
6027**
6028** Every [application-defined SQL function] that invokes this interface
6029** should include the [SQLITE_SUBTYPE] property in the text
6030** encoding argument when the function is [sqlite3_create_function|registered].
6031** If the [SQLITE_SUBTYPE] property is omitted, then sqlite3_value_subtype()
6032** might return zero instead of the upstream subtype in some corner cases.
6033*/
6034SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*);
6035
6036/*
6037** CAPI3REF: Copy And Free SQL Values
6038** METHOD: sqlite3_value
6039**
6040** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value]
6041** object V and returns a pointer to that copy. ^The [sqlite3_value] returned
6042** is a [protected sqlite3_value] object even if the input is not.
6043** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a
6044** memory allocation fails. ^If V is a [pointer value], then the result
6045** of sqlite3_value_dup(V) is a NULL value.
6046**
6047** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object
6048** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer
6049** then sqlite3_value_free(V) is a harmless no-op.
6050*/
6051SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*);
6052SQLITE_API void sqlite3_value_free(sqlite3_value*);
6053
6054/*
6055** CAPI3REF: Obtain Aggregate Function Context
6056** METHOD: sqlite3_context
6057**
6058** Implementations of aggregate SQL functions use this
6059** routine to allocate memory for storing their state.
6060**
6061** ^The first time the sqlite3_aggregate_context(C,N) routine is called
6062** for a particular aggregate function, SQLite allocates
6063** N bytes of memory, zeroes out that memory, and returns a pointer
6064** to the new memory. ^On second and subsequent calls to
6065** sqlite3_aggregate_context() for the same aggregate function instance,
6066** the same buffer is returned. Sqlite3_aggregate_context() is normally
6067** called once for each invocation of the xStep callback and then one
6068** last time when the xFinal callback is invoked. ^(When no rows match
6069** an aggregate query, the xStep() callback of the aggregate function
6070** implementation is never called and xFinal() is called exactly once.
6071** In those cases, sqlite3_aggregate_context() might be called for the
6072** first time from within xFinal().)^
6073**
6074** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer
6075** when first called if N is less than or equal to zero or if a memory
6076** allocation error occurs.
6077**
6078** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
6079** determined by the N parameter on the first successful call. Changing the
6080** value of N in any subsequent call to sqlite3_aggregate_context() within
6081** the same aggregate function instance will not resize the memory
6082** allocation.)^ Within the xFinal callback, it is customary to set
6083** N=0 in calls to sqlite3_aggregate_context(C,N) so that no
6084** pointless memory allocations occur.
6085**
6086** ^SQLite automatically frees the memory allocated by
6087** sqlite3_aggregate_context() when the aggregate query concludes.
6088**
6089** The first parameter must be a copy of the
6090** [sqlite3_context | SQL function context] that is the first parameter
6091** to the xStep or xFinal callback routine that implements the aggregate
6092** function.
6093**
6094** This routine must be called from the same thread in which
6095** the aggregate SQL function is running.
6096*/
6097SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
6098
6099/*
6100** CAPI3REF: User Data For Functions
6101** METHOD: sqlite3_context
6102**
6103** ^The sqlite3_user_data() interface returns a copy of
6104** the pointer that was the pUserData parameter (the 5th parameter)
6105** of the [sqlite3_create_function()]
6106** and [sqlite3_create_function16()] routines that originally
6107** registered the application defined function.
6108**
6109** This routine must be called from the same thread in which
6110** the application-defined function is running.
6111*/
6112SQLITE_API void *sqlite3_user_data(sqlite3_context*);
6113
6114/*
6115** CAPI3REF: Database Connection For Functions
6116** METHOD: sqlite3_context
6117**
6118** ^The sqlite3_context_db_handle() interface returns a copy of
6119** the pointer to the [database connection] (the 1st parameter)
6120** of the [sqlite3_create_function()]
6121** and [sqlite3_create_function16()] routines that originally
6122** registered the application defined function.
6123*/
6124SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*);
6125
6126/*
6127** CAPI3REF: Function Auxiliary Data
6128** METHOD: sqlite3_context
6129**
6130** These functions may be used by (non-aggregate) SQL functions to
6131** associate auxiliary data with argument values. If the same argument
6132** value is passed to multiple invocations of the same SQL function during
6133** query execution, under some circumstances the associated auxiliary data
6134** might be preserved. An example of where this might be useful is in a
6135** regular-expression matching function. The compiled version of the regular
6136** expression can be stored as auxiliary data associated with the pattern string.
6137** Then as long as the pattern string remains the same,
6138** the compiled regular expression can be reused on multiple
6139** invocations of the same function.
6140**
6141** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the auxiliary data
6142** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument
6143** value to the application-defined function. ^N is zero for the left-most
6144** function argument. ^If there is no auxiliary data
6145** associated with the function argument, the sqlite3_get_auxdata(C,N) interface
6146** returns a NULL pointer.
6147**
6148** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as auxiliary data for the
6149** N-th argument of the application-defined function. ^Subsequent
6150** calls to sqlite3_get_auxdata(C,N) return P from the most recent
6151** sqlite3_set_auxdata(C,N,P,X) call if the auxiliary data is still valid or
6152** NULL if the auxiliary data has been discarded.
6153** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL,
6154** SQLite will invoke the destructor function X with parameter P exactly
6155** once, when the auxiliary data is discarded.
6156** SQLite is free to discard the auxiliary data at any time, including: <ul>
6157** <li> ^(when the corresponding function parameter changes)^, or
6158** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the
6159** SQL statement)^, or
6160** <li> ^(when sqlite3_set_auxdata() is invoked again on the same
6161** parameter)^, or
6162** <li> ^(during the original sqlite3_set_auxdata() call when a memory
6163** allocation error occurs.)^
6164** <li> ^(during the original sqlite3_set_auxdata() call if the function
6165** is evaluated during query planning instead of during query execution,
6166** as sometimes happens with [SQLITE_ENABLE_STAT4].)^ </ul>
6167**
6168** Note the last two bullets in particular. The destructor X in
6169** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the
6170** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata()
6171** should be called near the end of the function implementation and the
6172** function implementation should not make any use of P after
6173** sqlite3_set_auxdata() has been called. Furthermore, a call to
6174** sqlite3_get_auxdata() that occurs immediately after a corresponding call
6175** to sqlite3_set_auxdata() might still return NULL if an out-of-memory
6176** condition occurred during the sqlite3_set_auxdata() call or if the
6177** function is being evaluated during query planning rather than during
6178** query execution.
6179**
6180** ^(In practice, auxiliary data is preserved between function calls for
6181** function parameters that are compile-time constants, including literal
6182** values and [parameters] and expressions composed from the same.)^
6183**
6184** The value of the N parameter to these interfaces should be non-negative.
6185** Future enhancements may make use of negative N values to define new
6186** kinds of function caching behavior.
6187**
6188** These routines must be called from the same thread in which
6189** the SQL function is running.
6190**
6191** See also: [sqlite3_get_clientdata()] and [sqlite3_set_clientdata()].
6192*/
6193SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N);
6194SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
6195
6196/*
6197** CAPI3REF: Database Connection Client Data
6198** METHOD: sqlite3
6199**
6200** These functions are used to associate one or more named pointers
6201** with a [database connection].
6202** A call to sqlite3_set_clientdata(D,N,P,X) causes the pointer P
6203** to be attached to [database connection] D using name N. Subsequent
6204** calls to sqlite3_get_clientdata(D,N) will return a copy of pointer P
6205** or a NULL pointer if there were no prior calls to
6206** sqlite3_set_clientdata() with the same values of D and N.
6207** Names are compared using strcmp() and are thus case sensitive.
6208**
6209** If P and X are both non-NULL, then the destructor X is invoked with
6210** argument P on the first of the following occurrences:
6211** <ul>
6212** <li> An out-of-memory error occurs during the call to
6213** sqlite3_set_clientdata() which attempts to register pointer P.
6214** <li> A subsequent call to sqlite3_set_clientdata(D,N,P,X) is made
6215** with the same D and N parameters.
6216** <li> The database connection closes. SQLite does not make any guarantees
6217** about the order in which destructors are called, only that all
6218** destructors will be called exactly once at some point during the
6219** database connection closing process.
6220** </ul>
6221**
6222** SQLite does not do anything with client data other than invoke
6223** destructors on the client data at the appropriate time. The intended
6224** use for client data is to provide a mechanism for wrapper libraries
6225** to store additional information about an SQLite database connection.
6226**
6227** There is no limit (other than available memory) on the number of different
6228** client data pointers (with different names) that can be attached to a
6229** single database connection. However, the implementation is optimized
6230** for the case of having only one or two different client data names.
6231** Applications and wrapper libraries are discouraged from using more than
6232** one client data name each.
6233**
6234** There is no way to enumerate the client data pointers
6235** associated with a database connection. The N parameter can be thought
6236** of as a secret key such that only code that knows the secret key is able
6237** to access the associated data.
6238**
6239** Security Warning: These interfaces should not be exposed in scripting
6240** languages or in other circumstances where it might be possible for an
6241** attacker to invoke them. Any agent that can invoke these interfaces
6242** can probably also take control of the process.
6243**
6244** Database connection client data is only available for SQLite
6245** version 3.44.0 ([dateof:3.44.0]) and later.
6246**
6247** See also: [sqlite3_set_auxdata()] and [sqlite3_get_auxdata()].
6248*/
6249SQLITE_API void *sqlite3_get_clientdata(sqlite3*,const char*);
6250SQLITE_API int sqlite3_set_clientdata(sqlite3*, const char*, void*, void(*)(void*));
6251
6252/*
6253** CAPI3REF: Constants Defining Special Destructor Behavior
6254**
6255** These are special values for the destructor that is passed in as the
6256** final argument to routines like [sqlite3_result_blob()]. ^If the destructor
6257** argument is SQLITE_STATIC, it means that the content pointer is constant
6258** and will never change. It does not need to be destroyed. ^The
6259** SQLITE_TRANSIENT value means that the content will likely change in
6260** the near future and that SQLite should make its own private copy of
6261** the content before returning.
6262**
6263** The typedef is necessary to work around problems in certain
6264** C++ compilers.
6265*/
6266typedef void (*sqlite3_destructor_type)(void*);
6267#define SQLITE_STATIC ((sqlite3_destructor_type)0)
6268#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1)
6269
6270/*
6271** CAPI3REF: Setting The Result Of An SQL Function
6272** METHOD: sqlite3_context
6273**
6274** These routines are used by the xFunc or xFinal callbacks that
6275** implement SQL functions and aggregates. See
6276** [sqlite3_create_function()] and [sqlite3_create_function16()]
6277** for additional information.
6278**
6279** These functions work very much like the [parameter binding] family of
6280** functions used to bind values to host parameters in prepared statements.
6281** Refer to the [SQL parameter] documentation for additional information.
6282**
6283** ^The sqlite3_result_blob() interface sets the result from
6284** an application-defined function to be the BLOB whose content is pointed
6285** to by the second parameter and which is N bytes long where N is the
6286** third parameter.
6287**
6288** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N)
6289** interfaces set the result of the application-defined function to be
6290** a BLOB containing all zero bytes and N bytes in size.
6291**
6292** ^The sqlite3_result_double() interface sets the result from
6293** an application-defined function to be a floating point value specified
6294** by its 2nd argument.
6295**
6296** ^The sqlite3_result_error() and sqlite3_result_error16() functions
6297** cause the implemented SQL function to throw an exception.
6298** ^SQLite uses the string pointed to by the
6299** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
6300** as the text of an error message. ^SQLite interprets the error
6301** message string from sqlite3_result_error() as UTF-8. ^SQLite
6302** interprets the string from sqlite3_result_error16() as UTF-16 using
6303** the same [byte-order determination rules] as [sqlite3_bind_text16()].
6304** ^If the third parameter to sqlite3_result_error()
6305** or sqlite3_result_error16() is negative then SQLite takes as the error
6306** message all text up through the first zero character.
6307** ^If the third parameter to sqlite3_result_error() or
6308** sqlite3_result_error16() is non-negative then SQLite takes that many
6309** bytes (not characters) from the 2nd parameter as the error message.
6310** ^The sqlite3_result_error() and sqlite3_result_error16()
6311** routines make a private copy of the error message text before
6312** they return. Hence, the calling function can deallocate or
6313** modify the text after they return without harm.
6314** ^The sqlite3_result_error_code() function changes the error code
6315** returned by SQLite as a result of an error in a function. ^By default,
6316** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error()
6317** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
6318**
6319** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an
6320** error indicating that a string or BLOB is too long to represent.
6321**
6322** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an
6323** error indicating that a memory allocation failed.
6324**
6325** ^The sqlite3_result_int() interface sets the return value
6326** of the application-defined function to be the 32-bit signed integer
6327** value given in the 2nd argument.
6328** ^The sqlite3_result_int64() interface sets the return value
6329** of the application-defined function to be the 64-bit signed integer
6330** value given in the 2nd argument.
6331**
6332** ^The sqlite3_result_null() interface sets the return value
6333** of the application-defined function to be NULL.
6334**
6335** ^The sqlite3_result_text(), sqlite3_result_text16(),
6336** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
6337** set the return value of the application-defined function to be
6338** a text string which is represented as UTF-8, UTF-16 native byte order,
6339** UTF-16 little endian, or UTF-16 big endian, respectively.
6340** ^The sqlite3_result_text64() interface sets the return value of an
6341** application-defined function to be a text string in an encoding
6342** specified by the fifth (and last) parameter, which must be one
6343** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE].
6344** ^SQLite takes the text result from the application from
6345** the 2nd parameter of the sqlite3_result_text* interfaces.
6346** ^If the 3rd parameter to any of the sqlite3_result_text* interfaces
6347** other than sqlite3_result_text64() is negative, then SQLite computes
6348** the string length itself by searching the 2nd parameter for the first
6349** zero character.
6350** ^If the 3rd parameter to the sqlite3_result_text* interfaces
6351** is non-negative, then as many bytes (not characters) of the text
6352** pointed to by the 2nd parameter are taken as the application-defined
6353** function result. If the 3rd parameter is non-negative, then it
6354** must be the byte offset into the string where the NUL terminator would
6355** appear if the string were NUL terminated. If any NUL characters occur
6356** in the string at a byte offset that is less than the value of the 3rd
6357** parameter, then the resulting string will contain embedded NULs and the
6358** result of expressions operating on strings with embedded NULs is undefined.
6359** ^If the 4th parameter to the sqlite3_result_text* interfaces
6360** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
6361** function as the destructor on the text or BLOB result when it has
6362** finished using that result.
6363** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
6364** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
6365** assumes that the text or BLOB result is in constant space and does not
6366** copy the content of the parameter nor call a destructor on the content
6367** when it has finished using that result.
6368** ^If the 4th parameter to the sqlite3_result_text* interfaces
6369** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
6370** then SQLite makes a copy of the result into space obtained
6371** from [sqlite3_malloc()] before it returns.
6372**
6373** ^For the sqlite3_result_text16(), sqlite3_result_text16le(), and
6374** sqlite3_result_text16be() routines, and for sqlite3_result_text64()
6375** when the encoding is not UTF8, if the input UTF16 begins with a
6376** byte-order mark (BOM, U+FEFF) then the BOM is removed from the
6377** string and the rest of the string is interpreted according to the
6378** byte-order specified by the BOM. ^The byte-order specified by
6379** the BOM at the beginning of the text overrides the byte-order
6380** specified by the interface procedure. ^So, for example, if
6381** sqlite3_result_text16le() is invoked with text that begins
6382** with bytes 0xfe, 0xff (a big-endian byte-order mark) then the
6383** first two bytes of input are skipped and the remaining input
6384** is interpreted as UTF16BE text.
6385**
6386** ^For UTF16 input text to the sqlite3_result_text16(),
6387** sqlite3_result_text16be(), sqlite3_result_text16le(), and
6388** sqlite3_result_text64() routines, if the text contains invalid
6389** UTF16 characters, the invalid characters might be converted
6390** into the unicode replacement character, U+FFFD.
6391**
6392** ^The sqlite3_result_value() interface sets the result of
6393** the application-defined function to be a copy of the
6394** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The
6395** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
6396** so that the [sqlite3_value] specified in the parameter may change or
6397** be deallocated after sqlite3_result_value() returns without harm.
6398** ^A [protected sqlite3_value] object may always be used where an
6399** [unprotected sqlite3_value] object is required, so either
6400** kind of [sqlite3_value] object can be used with this interface.
6401**
6402** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an
6403** SQL NULL value, just like [sqlite3_result_null(C)], except that it
6404** also associates the host-language pointer P or type T with that
6405** NULL value such that the pointer can be retrieved within an
6406** [application-defined SQL function] using [sqlite3_value_pointer()].
6407** ^If the D parameter is not NULL, then it is a pointer to a destructor
6408** for the P parameter. ^SQLite invokes D with P as its only argument
6409** when SQLite is finished with P. The T parameter should be a static
6410** string and preferably a string literal. The sqlite3_result_pointer()
6411** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
6412**
6413** If these routines are called from within a different thread
6414** than the one containing the application-defined function that received
6415** the [sqlite3_context] pointer, the results are undefined.
6416*/
6417SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
6418SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*,
6419 sqlite3_uint64,void(*)(void*));
6420SQLITE_API void sqlite3_result_double(sqlite3_context*, double);
6421SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int);
6422SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int);
6423SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*);
6424SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*);
6425SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int);
6426SQLITE_API void sqlite3_result_int(sqlite3_context*, int);
6427SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
6428SQLITE_API void sqlite3_result_null(sqlite3_context*);
6429SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
6430SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64,
6431 void(*)(void*), unsigned char encoding);
6432SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
6433SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
6434SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
6435SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
6436SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*));
6437SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n);
6438SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n);
6439
6440
6441/*
6442** CAPI3REF: Setting The Subtype Of An SQL Function
6443** METHOD: sqlite3_context
6444**
6445** The sqlite3_result_subtype(C,T) function causes the subtype of
6446** the result from the [application-defined SQL function] with
6447** [sqlite3_context] C to be the value T. Only the lower 8 bits
6448** of the subtype T are preserved in current versions of SQLite;
6449** higher order bits are discarded.
6450** The number of subtype bytes preserved by SQLite might increase
6451** in future releases of SQLite.
6452**
6453** Every [application-defined SQL function] that invokes this interface
6454** should include the [SQLITE_RESULT_SUBTYPE] property in its
6455** text encoding argument when the SQL function is
6456** [sqlite3_create_function|registered]. If the [SQLITE_RESULT_SUBTYPE]
6457** property is omitted from the function that invokes sqlite3_result_subtype(),
6458** then in some cases the sqlite3_result_subtype() might fail to set
6459** the result subtype.
6460**
6461** If SQLite is compiled with -DSQLITE_STRICT_SUBTYPE=1, then any
6462** SQL function that invokes the sqlite3_result_subtype() interface
6463** and that does not have the SQLITE_RESULT_SUBTYPE property will raise
6464** an error. Future versions of SQLite might enable -DSQLITE_STRICT_SUBTYPE=1
6465** by default.
6466*/
6467SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int);
6468
6469/*
6470** CAPI3REF: Define New Collating Sequences
6471** METHOD: sqlite3
6472**
6473** ^These functions add, remove, or modify a [collation] associated
6474** with the [database connection] specified as the first argument.
6475**
6476** ^The name of the collation is a UTF-8 string
6477** for sqlite3_create_collation() and sqlite3_create_collation_v2()
6478** and a UTF-16 string in native byte order for sqlite3_create_collation16().
6479** ^Collation names that compare equal according to [sqlite3_strnicmp()] are
6480** considered to be the same name.
6481**
6482** ^(The third argument (eTextRep) must be one of the constants:
6483** <ul>
6484** <li> [SQLITE_UTF8],
6485** <li> [SQLITE_UTF16LE],
6486** <li> [SQLITE_UTF16BE],
6487** <li> [SQLITE_UTF16], or
6488** <li> [SQLITE_UTF16_ALIGNED].
6489** </ul>)^
6490** ^The eTextRep argument determines the encoding of strings passed
6491** to the collating function callback, xCompare.
6492** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
6493** force strings to be UTF16 with native byte order.
6494** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
6495** on an even byte address.
6496**
6497** ^The fourth argument, pArg, is an application data pointer that is passed
6498** through as the first argument to the collating function callback.
6499**
6500** ^The fifth argument, xCompare, is a pointer to the collating function.
6501** ^Multiple collating functions can be registered using the same name but
6502** with different eTextRep parameters and SQLite will use whichever
6503** function requires the least amount of data transformation.
6504** ^If the xCompare argument is NULL then the collating function is
6505** deleted. ^When all collating functions having the same name are deleted,
6506** that collation is no longer usable.
6507**
6508** ^The collating function callback is invoked with a copy of the pArg
6509** application data pointer and with two strings in the encoding specified
6510** by the eTextRep argument. The two integer parameters to the collating
6511** function callback are the length of the two strings, in bytes. The collating
6512** function must return an integer that is negative, zero, or positive
6513** if the first string is less than, equal to, or greater than the second,
6514** respectively. A collating function must always return the same answer
6515** given the same inputs. If two or more collating functions are registered
6516** to the same collation name (using different eTextRep values) then all
6517** must give an equivalent answer when invoked with equivalent strings.
6518** The collating function must obey the following properties for all
6519** strings A, B, and C:
6520**
6521** <ol>
6522** <li> If A==B then B==A.
6523** <li> If A==B and B==C then A==C.
6524** <li> If A<B THEN B>A.
6525** <li> If A<B and B<C then A<C.
6526** </ol>
6527**
6528** If a collating function fails any of the above constraints and that
6529** collating function is registered and used, then the behavior of SQLite
6530** is undefined.
6531**
6532** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
6533** with the addition that the xDestroy callback is invoked on pArg when
6534** the collating function is deleted.
6535** ^Collating functions are deleted when they are overridden by later
6536** calls to the collation creation functions or when the
6537** [database connection] is closed using [sqlite3_close()].
6538**
6539** ^The xDestroy callback is <u>not</u> called if the
6540** sqlite3_create_collation_v2() function fails. Applications that invoke
6541** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should
6542** check the return code and dispose of the application data pointer
6543** themselves rather than expecting SQLite to deal with it for them.
6544** This is different from every other SQLite interface. The inconsistency
6545** is unfortunate but cannot be changed without breaking backwards
6546** compatibility.
6547**
6548** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
6549*/
6550SQLITE_API int sqlite3_create_collation(
6551 sqlite3*,
6552 const char *zName,
6553 int eTextRep,
6554 void *pArg,
6555 int(*xCompare)(void*,int,const void*,int,const void*)
6556);
6557SQLITE_API int sqlite3_create_collation_v2(
6558 sqlite3*,
6559 const char *zName,
6560 int eTextRep,
6561 void *pArg,
6562 int(*xCompare)(void*,int,const void*,int,const void*),
6563 void(*xDestroy)(void*)
6564);
6565SQLITE_API int sqlite3_create_collation16(
6566 sqlite3*,
6567 const void *zName,
6568 int eTextRep,
6569 void *pArg,
6570 int(*xCompare)(void*,int,const void*,int,const void*)
6571);
6572
6573/*
6574** CAPI3REF: Collation Needed Callbacks
6575** METHOD: sqlite3
6576**
6577** ^To avoid having to register all collation sequences before a database
6578** can be used, a single callback function may be registered with the
6579** [database connection] to be invoked whenever an undefined collation
6580** sequence is required.
6581**
6582** ^If the function is registered using the sqlite3_collation_needed() API,
6583** then it is passed the names of undefined collation sequences as strings
6584** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
6585** the names are passed as UTF-16 in machine native byte order.
6586** ^A call to either function replaces the existing collation-needed callback.
6587**
6588** ^(When the callback is invoked, the first argument passed is a copy
6589** of the second argument to sqlite3_collation_needed() or
6590** sqlite3_collation_needed16(). The second argument is the database
6591** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
6592** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
6593** sequence function required. The fourth parameter is the name of the
6594** required collation sequence.)^
6595**
6596** The callback function should register the desired collation using
6597** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
6598** [sqlite3_create_collation_v2()].
6599*/
6600SQLITE_API int sqlite3_collation_needed(
6601 sqlite3*,
6602 void*,
6603 void(*)(void*,sqlite3*,int eTextRep,const char*)
6604);
6605SQLITE_API int sqlite3_collation_needed16(
6606 sqlite3*,
6607 void*,
6608 void(*)(void*,sqlite3*,int eTextRep,const void*)
6609);
6610
6611#ifdef SQLITE_ENABLE_CEROD
6612/*
6613** Specify the activation key for a CEROD database. Unless
6614** activated, none of the CEROD routines will work.
6615*/
6616SQLITE_API void sqlite3_activate_cerod(
6617 const char *zPassPhrase /* Activation phrase */
6618);
6619#endif
6620
6621/*
6622** CAPI3REF: Suspend Execution For A Short Time
6623**
6624** The sqlite3_sleep() function causes the current thread to suspend execution
6625** for at least a number of milliseconds specified in its parameter.
6626**
6627** If the operating system does not support sleep requests with
6628** millisecond time resolution, then the time will be rounded up to
6629** the nearest second. The number of milliseconds of sleep actually
6630** requested from the operating system is returned.
6631**
6632** ^SQLite implements this interface by calling the xSleep()
6633** method of the default [sqlite3_vfs] object. If the xSleep() method
6634** of the default VFS is not implemented correctly, or not implemented at
6635** all, then the behavior of sqlite3_sleep() may deviate from the description
6636** in the previous paragraphs.
6637**
6638** If a negative argument is passed to sqlite3_sleep() the results vary by
6639** VFS and operating system. Some system treat a negative argument as an
6640** instruction to sleep forever. Others understand it to mean do not sleep
6641** at all. ^In SQLite version 3.42.0 and later, a negative
6642** argument passed into sqlite3_sleep() is changed to zero before it is relayed
6643** down into the xSleep method of the VFS.
6644*/
6645SQLITE_API int sqlite3_sleep(int);
6646
6647/*
6648** CAPI3REF: Name Of The Folder Holding Temporary Files
6649**
6650** ^(If this global variable is made to point to a string which is
6651** the name of a folder (a.k.a. directory), then all temporary files
6652** created by SQLite when using a built-in [sqlite3_vfs | VFS]
6653** will be placed in that directory.)^ ^If this variable
6654** is a NULL pointer, then SQLite performs a search for an appropriate
6655** temporary file directory.
6656**
6657** Applications are strongly discouraged from using this global variable.
6658** It is required to set a temporary folder on Windows Runtime (WinRT).
6659** But for all other platforms, it is highly recommended that applications
6660** neither read nor write this variable. This global variable is a relic
6661** that exists for backwards compatibility of legacy applications and should
6662** be avoided in new projects.
6663**
6664** It is not safe to read or modify this variable in more than one
6665** thread at a time. It is not safe to read or modify this variable
6666** if a [database connection] is being used at the same time in a separate
6667** thread.
6668** It is intended that this variable be set once
6669** as part of process initialization and before any SQLite interface
6670** routines have been called and that this variable remain unchanged
6671** thereafter.
6672**
6673** ^The [temp_store_directory pragma] may modify this variable and cause
6674** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
6675** the [temp_store_directory pragma] always assumes that any string
6676** that this variable points to is held in memory obtained from
6677** [sqlite3_malloc] and the pragma may attempt to free that memory
6678** using [sqlite3_free].
6679** Hence, if this variable is modified directly, either it should be
6680** made NULL or made to point to memory obtained from [sqlite3_malloc]
6681** or else the use of the [temp_store_directory pragma] should be avoided.
6682** Except when requested by the [temp_store_directory pragma], SQLite
6683** does not free the memory that sqlite3_temp_directory points to. If
6684** the application wants that memory to be freed, it must do
6685** so itself, taking care to only do so after all [database connection]
6686** objects have been destroyed.
6687**
6688** <b>Note to Windows Runtime users:</b> The temporary directory must be set
6689** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various
6690** features that require the use of temporary files may fail. Here is an
6691** example of how to do this using C++ with the Windows Runtime:
6692**
6693** <blockquote><pre>
6694** LPCWSTR zPath = Windows::Storage::ApplicationData::Current->
6695** TemporaryFolder->Path->Data();
6696** char zPathBuf[MAX_PATH + 1];
6697** memset(zPathBuf, 0, sizeof(zPathBuf));
6698** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf),
6699** NULL, NULL);
6700** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf);
6701** </pre></blockquote>
6702*/
6703SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory;
6704
6705/*
6706** CAPI3REF: Name Of The Folder Holding Database Files
6707**
6708** ^(If this global variable is made to point to a string which is
6709** the name of a folder (a.k.a. directory), then all database files
6710** specified with a relative pathname and created or accessed by
6711** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed
6712** to be relative to that directory.)^ ^If this variable is a NULL
6713** pointer, then SQLite assumes that all database files specified
6714** with a relative pathname are relative to the current directory
6715** for the process. Only the windows VFS makes use of this global
6716** variable; it is ignored by the unix VFS.
6717**
6718** Changing the value of this variable while a database connection is
6719** open can result in a corrupt database.
6720**
6721** It is not safe to read or modify this variable in more than one
6722** thread at a time. It is not safe to read or modify this variable
6723** if a [database connection] is being used at the same time in a separate
6724** thread.
6725** It is intended that this variable be set once
6726** as part of process initialization and before any SQLite interface
6727** routines have been called and that this variable remain unchanged
6728** thereafter.
6729**
6730** ^The [data_store_directory pragma] may modify this variable and cause
6731** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
6732** the [data_store_directory pragma] always assumes that any string
6733** that this variable points to is held in memory obtained from
6734** [sqlite3_malloc] and the pragma may attempt to free that memory
6735** using [sqlite3_free].
6736** Hence, if this variable is modified directly, either it should be
6737** made NULL or made to point to memory obtained from [sqlite3_malloc]
6738** or else the use of the [data_store_directory pragma] should be avoided.
6739*/
6740SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory;
6741
6742/*
6743** CAPI3REF: Win32 Specific Interface
6744**
6745** These interfaces are available only on Windows. The
6746** [sqlite3_win32_set_directory] interface is used to set the value associated
6747** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to
6748** zValue, depending on the value of the type parameter. The zValue parameter
6749** should be NULL to cause the previous value to be freed via [sqlite3_free];
6750** a non-NULL value will be copied into memory obtained from [sqlite3_malloc]
6751** prior to being used. The [sqlite3_win32_set_directory] interface returns
6752** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported,
6753** or [SQLITE_NOMEM] if memory could not be allocated. The value of the
6754** [sqlite3_data_directory] variable is intended to act as a replacement for
6755** the current directory on the sub-platforms of Win32 where that concept is
6756** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and
6757** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the
6758** sqlite3_win32_set_directory interface except the string parameter must be
6759** UTF-8 or UTF-16, respectively.
6760*/
6761SQLITE_API int sqlite3_win32_set_directory(
6762 unsigned long type, /* Identifier for directory being set or reset */
6763 void *zValue /* New value for directory being set or reset */
6764);
6765SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue);
6766SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue);
6767
6768/*
6769** CAPI3REF: Win32 Directory Types
6770**
6771** These macros are only available on Windows. They define the allowed values
6772** for the type argument to the [sqlite3_win32_set_directory] interface.
6773*/
6774#define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1
6775#define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2
6776
6777/*
6778** CAPI3REF: Test For Auto-Commit Mode
6779** KEYWORDS: {autocommit mode}
6780** METHOD: sqlite3
6781**
6782** ^The sqlite3_get_autocommit() interface returns non-zero or
6783** zero if the given database connection is or is not in autocommit mode,
6784** respectively. ^Autocommit mode is on by default.
6785** ^Autocommit mode is disabled by a [BEGIN] statement.
6786** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
6787**
6788** If certain kinds of errors occur on a statement within a multi-statement
6789** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
6790** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
6791** transaction might be rolled back automatically. The only way to
6792** find out whether SQLite automatically rolled back the transaction after
6793** an error is to use this function.
6794**
6795** If another thread changes the autocommit status of the database
6796** connection while this routine is running, then the return value
6797** is undefined.
6798*/
6799SQLITE_API int sqlite3_get_autocommit(sqlite3*);
6800
6801/*
6802** CAPI3REF: Find The Database Handle Of A Prepared Statement
6803** METHOD: sqlite3_stmt
6804**
6805** ^The sqlite3_db_handle interface returns the [database connection] handle
6806** to which a [prepared statement] belongs. ^The [database connection]
6807** returned by sqlite3_db_handle is the same [database connection]
6808** that was the first argument
6809** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
6810** create the statement in the first place.
6811*/
6812SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
6813
6814/*
6815** CAPI3REF: Return The Schema Name For A Database Connection
6816** METHOD: sqlite3
6817**
6818** ^The sqlite3_db_name(D,N) interface returns a pointer to the schema name
6819** for the N-th database on database connection D, or a NULL pointer if N is
6820** out of range. An N value of 0 means the main database file. An N of 1 is
6821** the "temp" schema. Larger values of N correspond to various ATTACH-ed
6822** databases.
6823**
6824** Space to hold the string that is returned by sqlite3_db_name() is managed
6825** by SQLite itself. The string might be deallocated by any operation that
6826** changes the schema, including [ATTACH] or [DETACH] or calls to
6827** [sqlite3_serialize()] or [sqlite3_deserialize()], even operations that
6828** occur on a different thread. Applications that need to
6829** remember the string long-term should make their own copy. Applications that
6830** are accessing the same database connection simultaneously on multiple
6831** threads should mutex-protect calls to this API and should make their own
6832** private copy of the result prior to releasing the mutex.
6833*/
6834SQLITE_API const char *sqlite3_db_name(sqlite3 *db, int N);
6835
6836/*
6837** CAPI3REF: Return The Filename For A Database Connection
6838** METHOD: sqlite3
6839**
6840** ^The sqlite3_db_filename(D,N) interface returns a pointer to the filename
6841** associated with database N of connection D.
6842** ^If there is no attached database N on the database
6843** connection D, or if database N is a temporary or in-memory database, then
6844** this function will return either a NULL pointer or an empty string.
6845**
6846** ^The string value returned by this routine is owned and managed by
6847** the database connection. ^The value will be valid until the database N
6848** is [DETACH]-ed or until the database connection closes.
6849**
6850** ^The filename returned by this function is the output of the
6851** xFullPathname method of the [VFS]. ^In other words, the filename
6852** will be an absolute pathname, even if the filename used
6853** to open the database originally was a URI or relative pathname.
6854**
6855** If the filename pointer returned by this routine is not NULL, then it
6856** can be used as the filename input parameter to these routines:
6857** <ul>
6858** <li> [sqlite3_uri_parameter()]
6859** <li> [sqlite3_uri_boolean()]
6860** <li> [sqlite3_uri_int64()]
6861** <li> [sqlite3_filename_database()]
6862** <li> [sqlite3_filename_journal()]
6863** <li> [sqlite3_filename_wal()]
6864** </ul>
6865*/
6866SQLITE_API sqlite3_filename sqlite3_db_filename(sqlite3 *db, const char *zDbName);
6867
6868/*
6869** CAPI3REF: Determine if a database is read-only
6870** METHOD: sqlite3
6871**
6872** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N
6873** of connection D is read-only, 0 if it is read/write, or -1 if N is not
6874** the name of a database on connection D.
6875*/
6876SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName);
6877
6878/*
6879** CAPI3REF: Determine the transaction state of a database
6880** METHOD: sqlite3
6881**
6882** ^The sqlite3_txn_state(D,S) interface returns the current
6883** [transaction state] of schema S in database connection D. ^If S is NULL,
6884** then the highest transaction state of any schema on database connection D
6885** is returned. Transaction states are (in order of lowest to highest):
6886** <ol>
6887** <li value="0"> SQLITE_TXN_NONE
6888** <li value="1"> SQLITE_TXN_READ
6889** <li value="2"> SQLITE_TXN_WRITE
6890** </ol>
6891** ^If the S argument to sqlite3_txn_state(D,S) is not the name of
6892** a valid schema, then -1 is returned.
6893*/
6894SQLITE_API int sqlite3_txn_state(sqlite3*,const char *zSchema);
6895
6896/*
6897** CAPI3REF: Allowed return values from sqlite3_txn_state()
6898** KEYWORDS: {transaction state}
6899**
6900** These constants define the current transaction state of a database file.
6901** ^The [sqlite3_txn_state(D,S)] interface returns one of these
6902** constants in order to describe the transaction state of schema S
6903** in [database connection] D.
6904**
6905** <dl>
6906** [[SQLITE_TXN_NONE]] <dt>SQLITE_TXN_NONE</dt>
6907** <dd>The SQLITE_TXN_NONE state means that no transaction is currently
6908** pending.</dd>
6909**
6910** [[SQLITE_TXN_READ]] <dt>SQLITE_TXN_READ</dt>
6911** <dd>The SQLITE_TXN_READ state means that the database is currently
6912** in a read transaction. Content has been read from the database file
6913** but nothing in the database file has changed. The transaction state
6914** will be advanced to SQLITE_TXN_WRITE if any changes occur and there are
6915** no other conflicting concurrent write transactions. The transaction
6916** state will revert to SQLITE_TXN_NONE following a [ROLLBACK] or
6917** [COMMIT].</dd>
6918**
6919** [[SQLITE_TXN_WRITE]] <dt>SQLITE_TXN_WRITE</dt>
6920** <dd>The SQLITE_TXN_WRITE state means that the database is currently
6921** in a write transaction. Content has been written to the database file
6922** but has not yet committed. The transaction state will change to
6923** SQLITE_TXN_NONE at the next [ROLLBACK] or [COMMIT].</dd>
6924*/
6925#define SQLITE_TXN_NONE 0
6926#define SQLITE_TXN_READ 1
6927#define SQLITE_TXN_WRITE 2
6928
6929/*
6930** CAPI3REF: Find the next prepared statement
6931** METHOD: sqlite3
6932**
6933** ^This interface returns a pointer to the next [prepared statement] after
6934** pStmt associated with the [database connection] pDb. ^If pStmt is NULL
6935** then this interface returns a pointer to the first prepared statement
6936** associated with the database connection pDb. ^If no prepared statement
6937** satisfies the conditions of this routine, it returns NULL.
6938**
6939** The [database connection] pointer D in a call to
6940** [sqlite3_next_stmt(D,S)] must refer to an open database
6941** connection and in particular must not be a NULL pointer.
6942*/
6943SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
6944
6945/*
6946** CAPI3REF: Commit And Rollback Notification Callbacks
6947** METHOD: sqlite3
6948**
6949** ^The sqlite3_commit_hook() interface registers a callback
6950** function to be invoked whenever a transaction is [COMMIT | committed].
6951** ^Any callback set by a previous call to sqlite3_commit_hook()
6952** for the same database connection is overridden.
6953** ^The sqlite3_rollback_hook() interface registers a callback
6954** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
6955** ^Any callback set by a previous call to sqlite3_rollback_hook()
6956** for the same database connection is overridden.
6957** ^The pArg argument is passed through to the callback.
6958** ^If the callback on a commit hook function returns non-zero,
6959** then the commit is converted into a rollback.
6960**
6961** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
6962** return the P argument from the previous call of the same function
6963** on the same [database connection] D, or NULL for
6964** the first call for each function on D.
6965**
6966** The commit and rollback hook callbacks are not reentrant.
6967** The callback implementation must not do anything that will modify
6968** the database connection that invoked the callback. Any actions
6969** to modify the database connection must be deferred until after the
6970** completion of the [sqlite3_step()] call that triggered the commit
6971** or rollback hook in the first place.
6972** Note that running any other SQL statements, including SELECT statements,
6973** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify
6974** the database connections for the meaning of "modify" in this paragraph.
6975**
6976** ^Registering a NULL function disables the callback.
6977**
6978** ^When the commit hook callback routine returns zero, the [COMMIT]
6979** operation is allowed to continue normally. ^If the commit hook
6980** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
6981** ^The rollback hook is invoked on a rollback that results from a commit
6982** hook returning non-zero, just as it would be with any other rollback.
6983**
6984** ^For the purposes of this API, a transaction is said to have been
6985** rolled back if an explicit "ROLLBACK" statement is executed, or
6986** an error or constraint causes an implicit rollback to occur.
6987** ^The rollback callback is not invoked if a transaction is
6988** automatically rolled back because the database connection is closed.
6989**
6990** See also the [sqlite3_update_hook()] interface.
6991*/
6992SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
6993SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
6994
6995/*
6996** CAPI3REF: Autovacuum Compaction Amount Callback
6997** METHOD: sqlite3
6998**
6999** ^The sqlite3_autovacuum_pages(D,C,P,X) interface registers a callback
7000** function C that is invoked prior to each autovacuum of the database
7001** file. ^The callback is passed a copy of the generic data pointer (P),
7002** the schema-name of the attached database that is being autovacuumed,
7003** the size of the database file in pages, the number of free pages,
7004** and the number of bytes per page, respectively. The callback should
7005** return the number of free pages that should be removed by the
7006** autovacuum. ^If the callback returns zero, then no autovacuum happens.
7007** ^If the value returned is greater than or equal to the number of
7008** free pages, then a complete autovacuum happens.
7009**
7010** <p>^If there are multiple ATTACH-ed database files that are being
7011** modified as part of a transaction commit, then the autovacuum pages
7012** callback is invoked separately for each file.
7013**
7014** <p><b>The callback is not reentrant.</b> The callback function should
7015** not attempt to invoke any other SQLite interface. If it does, bad
7016** things may happen, including segmentation faults and corrupt database
7017** files. The callback function should be a simple function that
7018** does some arithmetic on its input parameters and returns a result.
7019**
7020** ^The X parameter to sqlite3_autovacuum_pages(D,C,P,X) is an optional
7021** destructor for the P parameter. ^If X is not NULL, then X(P) is
7022** invoked whenever the database connection closes or when the callback
7023** is overwritten by another invocation of sqlite3_autovacuum_pages().
7024**
7025** <p>^There is only one autovacuum pages callback per database connection.
7026** ^Each call to the sqlite3_autovacuum_pages() interface overrides all
7027** previous invocations for that database connection. ^If the callback
7028** argument (C) to sqlite3_autovacuum_pages(D,C,P,X) is a NULL pointer,
7029** then the autovacuum steps callback is canceled. The return value
7030** from sqlite3_autovacuum_pages() is normally SQLITE_OK, but might
7031** be some other error code if something goes wrong. The current
7032** implementation will only return SQLITE_OK or SQLITE_MISUSE, but other
7033** return codes might be added in future releases.
7034**
7035** <p>If no autovacuum pages callback is specified (the usual case) or
7036** a NULL pointer is provided for the callback,
7037** then the default behavior is to vacuum all free pages. So, in other
7038** words, the default behavior is the same as if the callback function
7039** were something like this:
7040**
7041** <blockquote><pre>
7042** unsigned int demonstration_autovac_pages_callback(
7043** void *pClientData,
7044** const char *zSchema,
7045** unsigned int nDbPage,
7046** unsigned int nFreePage,
7047** unsigned int nBytePerPage
7048** ){
7049** return nFreePage;
7050** }
7051** </pre></blockquote>
7052*/
7053SQLITE_API int sqlite3_autovacuum_pages(
7054 sqlite3 *db,
7055 unsigned int(*)(void*,const char*,unsigned int,unsigned int,unsigned int),
7056 void*,
7057 void(*)(void*)
7058);
7059
7060
7061/*
7062** CAPI3REF: Data Change Notification Callbacks
7063** METHOD: sqlite3
7064**
7065** ^The sqlite3_update_hook() interface registers a callback function
7066** with the [database connection] identified by the first argument
7067** to be invoked whenever a row is updated, inserted or deleted in
7068** a [rowid table].
7069** ^Any callback set by a previous call to this function
7070** for the same database connection is overridden.
7071**
7072** ^The second argument is a pointer to the function to invoke when a
7073** row is updated, inserted or deleted in a rowid table.
7074** ^The update hook is disabled by invoking sqlite3_update_hook()
7075** with a NULL pointer as the second parameter.
7076** ^The first argument to the callback is a copy of the third argument
7077** to sqlite3_update_hook().
7078** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
7079** or [SQLITE_UPDATE], depending on the operation that caused the callback
7080** to be invoked.
7081** ^The third and fourth arguments to the callback contain pointers to the
7082** database and table name containing the affected row.
7083** ^The final callback parameter is the [rowid] of the row.
7084** ^In the case of an update, this is the [rowid] after the update takes place.
7085**
7086** ^(The update hook is not invoked when internal system tables are
7087** modified (i.e. sqlite_sequence).)^
7088** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified.
7089**
7090** ^In the current implementation, the update hook
7091** is not invoked when conflicting rows are deleted because of an
7092** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook
7093** invoked when rows are deleted using the [truncate optimization].
7094** The exceptions defined in this paragraph might change in a future
7095** release of SQLite.
7096**
7097** Whether the update hook is invoked before or after the
7098** corresponding change is currently unspecified and may differ
7099** depending on the type of change. Do not rely on the order of the
7100** hook call with regards to the final result of the operation which
7101** triggers the hook.
7102**
7103** The update hook implementation must not do anything that will modify
7104** the database connection that invoked the update hook. Any actions
7105** to modify the database connection must be deferred until after the
7106** completion of the [sqlite3_step()] call that triggered the update hook.
7107** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
7108** database connections for the meaning of "modify" in this paragraph.
7109**
7110** ^The sqlite3_update_hook(D,C,P) function
7111** returns the P argument from the previous call
7112** on the same [database connection] D, or NULL for
7113** the first call on D.
7114**
7115** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()],
7116** and [sqlite3_preupdate_hook()] interfaces.
7117*/
7118SQLITE_API void *sqlite3_update_hook(
7119 sqlite3*,
7120 void(*)(void *,int ,char const *,char const *,sqlite3_int64),
7121 void*
7122);
7123
7124/*
7125** CAPI3REF: Enable Or Disable Shared Pager Cache
7126**
7127** ^(This routine enables or disables the sharing of the database cache
7128** and schema data structures between [database connection | connections]
7129** to the same database. Sharing is enabled if the argument is true
7130** and disabled if the argument is false.)^
7131**
7132** This interface is omitted if SQLite is compiled with
7133** [-DSQLITE_OMIT_SHARED_CACHE]. The [-DSQLITE_OMIT_SHARED_CACHE]
7134** compile-time option is recommended because the
7135** [use of shared cache mode is discouraged].
7136**
7137** ^Cache sharing is enabled and disabled for an entire process.
7138** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]).
7139** In prior versions of SQLite,
7140** sharing was enabled or disabled for each thread separately.
7141**
7142** ^(The cache sharing mode set by this interface effects all subsequent
7143** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
7144** Existing database connections continue to use the sharing mode
7145** that was in effect at the time they were opened.)^
7146**
7147** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
7148** successfully. An [error code] is returned otherwise.)^
7149**
7150** ^Shared cache is disabled by default. It is recommended that it stay
7151** that way. In other words, do not use this routine. This interface
7152** continues to be provided for historical compatibility, but its use is
7153** discouraged. Any use of shared cache is discouraged. If shared cache
7154** must be used, it is recommended that shared cache only be enabled for
7155** individual database connections using the [sqlite3_open_v2()] interface
7156** with the [SQLITE_OPEN_SHAREDCACHE] flag.
7157**
7158** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0
7159** and will always return SQLITE_MISUSE. On those systems,
7160** shared cache mode should be enabled per-database connection via
7161** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE].
7162**
7163** This interface is threadsafe on processors where writing a
7164** 32-bit integer is atomic.
7165**
7166** See Also: [SQLite Shared-Cache Mode]
7167*/
7168SQLITE_API int sqlite3_enable_shared_cache(int);
7169
7170/*
7171** CAPI3REF: Attempt To Free Heap Memory
7172**
7173** ^The sqlite3_release_memory() interface attempts to free N bytes
7174** of heap memory by deallocating non-essential memory allocations
7175** held by the database library. Memory used to cache database
7176** pages to improve performance is an example of non-essential memory.
7177** ^sqlite3_release_memory() returns the number of bytes actually freed,
7178** which might be more or less than the amount requested.
7179** ^The sqlite3_release_memory() routine is a no-op returning zero
7180** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
7181**
7182** See also: [sqlite3_db_release_memory()]
7183*/
7184SQLITE_API int sqlite3_release_memory(int);
7185
7186/*
7187** CAPI3REF: Free Memory Used By A Database Connection
7188** METHOD: sqlite3
7189**
7190** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap
7191** memory as possible from database connection D. Unlike the
7192** [sqlite3_release_memory()] interface, this interface is in effect even
7193** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is
7194** omitted.
7195**
7196** See also: [sqlite3_release_memory()]
7197*/
7198SQLITE_API int sqlite3_db_release_memory(sqlite3*);
7199
7200/*
7201** CAPI3REF: Impose A Limit On Heap Size
7202**
7203** These interfaces impose limits on the amount of heap memory that will be
7204** used by all database connections within a single process.
7205**
7206** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the
7207** soft limit on the amount of heap memory that may be allocated by SQLite.
7208** ^SQLite strives to keep heap memory utilization below the soft heap
7209** limit by reducing the number of pages held in the page cache
7210** as heap memory usages approaches the limit.
7211** ^The soft heap limit is "soft" because even though SQLite strives to stay
7212** below the limit, it will exceed the limit rather than generate
7213** an [SQLITE_NOMEM] error. In other words, the soft heap limit
7214** is advisory only.
7215**
7216** ^The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of
7217** N bytes on the amount of memory that will be allocated. ^The
7218** sqlite3_hard_heap_limit64(N) interface is similar to
7219** sqlite3_soft_heap_limit64(N) except that memory allocations will fail
7220** when the hard heap limit is reached.
7221**
7222** ^The return value from both sqlite3_soft_heap_limit64() and
7223** sqlite3_hard_heap_limit64() is the size of
7224** the heap limit prior to the call, or negative in the case of an
7225** error. ^If the argument N is negative
7226** then no change is made to the heap limit. Hence, the current
7227** size of heap limits can be determined by invoking
7228** sqlite3_soft_heap_limit64(-1) or sqlite3_hard_heap_limit(-1).
7229**
7230** ^Setting the heap limits to zero disables the heap limiter mechanism.
7231**
7232** ^The soft heap limit may not be greater than the hard heap limit.
7233** ^If the hard heap limit is enabled and if sqlite3_soft_heap_limit(N)
7234** is invoked with a value of N that is greater than the hard heap limit,
7235** the soft heap limit is set to the value of the hard heap limit.
7236** ^The soft heap limit is automatically enabled whenever the hard heap
7237** limit is enabled. ^When sqlite3_hard_heap_limit64(N) is invoked and
7238** the soft heap limit is outside the range of 1..N, then the soft heap
7239** limit is set to N. ^Invoking sqlite3_soft_heap_limit64(0) when the
7240** hard heap limit is enabled makes the soft heap limit equal to the
7241** hard heap limit.
7242**
7243** The memory allocation limits can also be adjusted using
7244** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit].
7245**
7246** ^(The heap limits are not enforced in the current implementation
7247** if one or more of following conditions are true:
7248**
7249** <ul>
7250** <li> The limit value is set to zero.
7251** <li> Memory accounting is disabled using a combination of the
7252** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
7253** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
7254** <li> An alternative page cache implementation is specified using
7255** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...).
7256** <li> The page cache allocates from its own memory pool supplied
7257** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
7258** from the heap.
7259** </ul>)^
7260**
7261** The circumstances under which SQLite will enforce the heap limits may
7262** change in future releases of SQLite.
7263*/
7264SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N);
7265SQLITE_API sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N);
7266
7267/*
7268** CAPI3REF: Deprecated Soft Heap Limit Interface
7269** DEPRECATED
7270**
7271** This is a deprecated version of the [sqlite3_soft_heap_limit64()]
7272** interface. This routine is provided for historical compatibility
7273** only. All new applications should use the
7274** [sqlite3_soft_heap_limit64()] interface rather than this one.
7275*/
7276SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N);
7277
7278
7279/*
7280** CAPI3REF: Extract Metadata About A Column Of A Table
7281** METHOD: sqlite3
7282**
7283** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns
7284** information about column C of table T in database D
7285** on [database connection] X.)^ ^The sqlite3_table_column_metadata()
7286** interface returns SQLITE_OK and fills in the non-NULL pointers in
7287** the final five arguments with appropriate values if the specified
7288** column exists. ^The sqlite3_table_column_metadata() interface returns
7289** SQLITE_ERROR if the specified column does not exist.
7290** ^If the column-name parameter to sqlite3_table_column_metadata() is a
7291** NULL pointer, then this routine simply checks for the existence of the
7292** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it
7293** does not. If the table name parameter T in a call to
7294** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is
7295** undefined behavior.
7296**
7297** ^The column is identified by the second, third and fourth parameters to
7298** this function. ^(The second parameter is either the name of the database
7299** (i.e. "main", "temp", or an attached database) containing the specified
7300** table or NULL.)^ ^If it is NULL, then all attached databases are searched
7301** for the table using the same algorithm used by the database engine to
7302** resolve unqualified table references.
7303**
7304** ^The third and fourth parameters to this function are the table and column
7305** name of the desired column, respectively.
7306**
7307** ^Metadata is returned by writing to the memory locations passed as the 5th
7308** and subsequent parameters to this function. ^Any of these arguments may be
7309** NULL, in which case the corresponding element of metadata is omitted.
7310**
7311** ^(<blockquote>
7312** <table border="1">
7313** <tr><th> Parameter <th> Output<br>Type <th> Description
7314**
7315** <tr><td> 5th <td> const char* <td> Data type
7316** <tr><td> 6th <td> const char* <td> Name of default collation sequence
7317** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint
7318** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY
7319** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT]
7320** </table>
7321** </blockquote>)^
7322**
7323** ^The memory pointed to by the character pointers returned for the
7324** declaration type and collation sequence is valid until the next
7325** call to any SQLite API function.
7326**
7327** ^If the specified table is actually a view, an [error code] is returned.
7328**
7329** ^If the specified column is "rowid", "oid" or "_rowid_" and the table
7330** is not a [WITHOUT ROWID] table and an
7331** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
7332** parameters are set for the explicitly declared column. ^(If there is no
7333** [INTEGER PRIMARY KEY] column, then the outputs
7334** for the [rowid] are set as follows:
7335**
7336** <pre>
7337** data type: "INTEGER"
7338** collation sequence: "BINARY"
7339** not null: 0
7340** primary key: 1
7341** auto increment: 0
7342** </pre>)^
7343**
7344** ^This function causes all database schemas to be read from disk and
7345** parsed, if that has not already been done, and returns an error if
7346** any errors are encountered while loading the schema.
7347*/
7348SQLITE_API int sqlite3_table_column_metadata(
7349 sqlite3 *db, /* Connection handle */
7350 const char *zDbName, /* Database name or NULL */
7351 const char *zTableName, /* Table name */
7352 const char *zColumnName, /* Column name */
7353 char const **pzDataType, /* OUTPUT: Declared data type */
7354 char const **pzCollSeq, /* OUTPUT: Collation sequence name */
7355 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */
7356 int *pPrimaryKey, /* OUTPUT: True if column part of PK */
7357 int *pAutoinc /* OUTPUT: True if column is auto-increment */
7358);
7359
7360/*
7361** CAPI3REF: Load An Extension
7362** METHOD: sqlite3
7363**
7364** ^This interface loads an SQLite extension library from the named file.
7365**
7366** ^The sqlite3_load_extension() interface attempts to load an
7367** [SQLite extension] library contained in the file zFile. If
7368** the file cannot be loaded directly, attempts are made to load
7369** with various operating-system specific extensions added.
7370** So for example, if "samplelib" cannot be loaded, then names like
7371** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might
7372** be tried also.
7373**
7374** ^The entry point is zProc.
7375** ^(zProc may be 0, in which case SQLite will try to come up with an
7376** entry point name on its own. It first tries "sqlite3_extension_init".
7377** If that does not work, it constructs a name "sqlite3_X_init" where
7378** X consists of the lower-case equivalent of all ASCII alphabetic
7379** characters in the filename from the last "/" to the first following
7380** "." and omitting any initial "lib".)^
7381** ^The sqlite3_load_extension() interface returns
7382** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
7383** ^If an error occurs and pzErrMsg is not 0, then the
7384** [sqlite3_load_extension()] interface shall attempt to
7385** fill *pzErrMsg with error message text stored in memory
7386** obtained from [sqlite3_malloc()]. The calling function
7387** should free this memory by calling [sqlite3_free()].
7388**
7389** ^Extension loading must be enabled using
7390** [sqlite3_enable_load_extension()] or
7391** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL)
7392** prior to calling this API,
7393** otherwise an error will be returned.
7394**
7395** <b>Security warning:</b> It is recommended that the
7396** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this
7397** interface. The use of the [sqlite3_enable_load_extension()] interface
7398** should be avoided. This will keep the SQL function [load_extension()]
7399** disabled and prevent SQL injections from giving attackers
7400** access to extension loading capabilities.
7401**
7402** See also the [load_extension() SQL function].
7403*/
7404SQLITE_API int sqlite3_load_extension(
7405 sqlite3 *db, /* Load the extension into this database connection */
7406 const char *zFile, /* Name of the shared library containing extension */
7407 const char *zProc, /* Entry point. Derived from zFile if 0 */
7408 char **pzErrMsg /* Put error message here if not 0 */
7409);
7410
7411/*
7412** CAPI3REF: Enable Or Disable Extension Loading
7413** METHOD: sqlite3
7414**
7415** ^So as not to open security holes in older applications that are
7416** unprepared to deal with [extension loading], and as a means of disabling
7417** [extension loading] while evaluating user-entered SQL, the following API
7418** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
7419**
7420** ^Extension loading is off by default.
7421** ^Call the sqlite3_enable_load_extension() routine with onoff==1
7422** to turn extension loading on and call it with onoff==0 to turn
7423** it back off again.
7424**
7425** ^This interface enables or disables both the C-API
7426** [sqlite3_load_extension()] and the SQL function [load_extension()].
7427** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..)
7428** to enable or disable only the C-API.)^
7429**
7430** <b>Security warning:</b> It is recommended that extension loading
7431** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method
7432** rather than this interface, so the [load_extension()] SQL function
7433** remains disabled. This will prevent SQL injections from giving attackers
7434** access to extension loading capabilities.
7435*/
7436SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
7437
7438/*
7439** CAPI3REF: Automatically Load Statically Linked Extensions
7440**
7441** ^This interface causes the xEntryPoint() function to be invoked for
7442** each new [database connection] that is created. The idea here is that
7443** xEntryPoint() is the entry point for a statically linked [SQLite extension]
7444** that is to be automatically loaded into all new database connections.
7445**
7446** ^(Even though the function prototype shows that xEntryPoint() takes
7447** no arguments and returns void, SQLite invokes xEntryPoint() with three
7448** arguments and expects an integer result as if the signature of the
7449** entry point were as follows:
7450**
7451** <blockquote><pre>
7452** int xEntryPoint(
7453** sqlite3 *db,
7454** const char **pzErrMsg,
7455** const struct sqlite3_api_routines *pThunk
7456** );
7457** </pre></blockquote>)^
7458**
7459** If the xEntryPoint routine encounters an error, it should make *pzErrMsg
7460** point to an appropriate error message (obtained from [sqlite3_mprintf()])
7461** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg
7462** is NULL before calling the xEntryPoint(). ^SQLite will invoke
7463** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any
7464** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],
7465** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.
7466**
7467** ^Calling sqlite3_auto_extension(X) with an entry point X that is already
7468** on the list of automatic extensions is a harmless no-op. ^No entry point
7469** will be called more than once for each database connection that is opened.
7470**
7471** See also: [sqlite3_reset_auto_extension()]
7472** and [sqlite3_cancel_auto_extension()]
7473*/
7474SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void));
7475
7476/*
7477** CAPI3REF: Cancel Automatic Extension Loading
7478**
7479** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the
7480** initialization routine X that was registered using a prior call to
7481** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)]
7482** routine returns 1 if initialization routine X was successfully
7483** unregistered and it returns 0 if X was not on the list of initialization
7484** routines.
7485*/
7486SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void));
7487
7488/*
7489** CAPI3REF: Reset Automatic Extension Loading
7490**
7491** ^This interface disables all automatic extensions previously
7492** registered using [sqlite3_auto_extension()].
7493*/
7494SQLITE_API void sqlite3_reset_auto_extension(void);
7495
7496/*
7497** Structures used by the virtual table interface
7498*/
7499typedef struct sqlite3_vtab sqlite3_vtab;
7500typedef struct sqlite3_index_info sqlite3_index_info;
7501typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
7502typedef struct sqlite3_module sqlite3_module;
7503
7504/*
7505** CAPI3REF: Virtual Table Object
7506** KEYWORDS: sqlite3_module {virtual table module}
7507**
7508** This structure, sometimes called a "virtual table module",
7509** defines the implementation of a [virtual table].
7510** This structure consists mostly of methods for the module.
7511**
7512** ^A virtual table module is created by filling in a persistent
7513** instance of this structure and passing a pointer to that instance
7514** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
7515** ^The registration remains valid until it is replaced by a different
7516** module or until the [database connection] closes. The content
7517** of this structure must not change while it is registered with
7518** any database connection.
7519*/
7520struct sqlite3_module {
7521 int iVersion;
7522 int (*xCreate)(sqlite3*, void *pAux,
7523 int argc, const char *const*argv,
7524 sqlite3_vtab **ppVTab, char**);
7525 int (*xConnect)(sqlite3*, void *pAux,
7526 int argc, const char *const*argv,
7527 sqlite3_vtab **ppVTab, char**);
7528 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
7529 int (*xDisconnect)(sqlite3_vtab *pVTab);
7530 int (*xDestroy)(sqlite3_vtab *pVTab);
7531 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
7532 int (*xClose)(sqlite3_vtab_cursor*);
7533 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
7534 int argc, sqlite3_value **argv);
7535 int (*xNext)(sqlite3_vtab_cursor*);
7536 int (*xEof)(sqlite3_vtab_cursor*);
7537 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
7538 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
7539 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
7540 int (*xBegin)(sqlite3_vtab *pVTab);
7541 int (*xSync)(sqlite3_vtab *pVTab);
7542 int (*xCommit)(sqlite3_vtab *pVTab);
7543 int (*xRollback)(sqlite3_vtab *pVTab);
7544 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
7545 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
7546 void **ppArg);
7547 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
7548 /* The methods above are in version 1 of the sqlite_module object. Those
7549 ** below are for version 2 and greater. */
7550 int (*xSavepoint)(sqlite3_vtab *pVTab, int);
7551 int (*xRelease)(sqlite3_vtab *pVTab, int);
7552 int (*xRollbackTo)(sqlite3_vtab *pVTab, int);
7553 /* The methods above are in versions 1 and 2 of the sqlite_module object.
7554 ** Those below are for version 3 and greater. */
7555 int (*xShadowName)(const char*);
7556 /* The methods above are in versions 1 through 3 of the sqlite_module object.
7557 ** Those below are for version 4 and greater. */
7558 int (*xIntegrity)(sqlite3_vtab *pVTab, const char *zSchema,
7559 const char *zTabName, int mFlags, char **pzErr);
7560};
7561
7562/*
7563** CAPI3REF: Virtual Table Indexing Information
7564** KEYWORDS: sqlite3_index_info
7565**
7566** The sqlite3_index_info structure and its substructures is used as part
7567** of the [virtual table] interface to
7568** pass information into and receive the reply from the [xBestIndex]
7569** method of a [virtual table module]. The fields under **Inputs** are the
7570** inputs to xBestIndex and are read-only. xBestIndex inserts its
7571** results into the **Outputs** fields.
7572**
7573** ^(The aConstraint[] array records WHERE clause constraints of the form:
7574**
7575** <blockquote>column OP expr</blockquote>
7576**
7577** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is
7578** stored in aConstraint[].op using one of the
7579** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^
7580** ^(The index of the column is stored in
7581** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the
7582** expr on the right-hand side can be evaluated (and thus the constraint
7583** is usable) and false if it cannot.)^
7584**
7585** ^The optimizer automatically inverts terms of the form "expr OP column"
7586** and makes other simplifications to the WHERE clause in an attempt to
7587** get as many WHERE clause terms into the form shown above as possible.
7588** ^The aConstraint[] array only reports WHERE clause terms that are
7589** relevant to the particular virtual table being queried.
7590**
7591** ^Information about the ORDER BY clause is stored in aOrderBy[].
7592** ^Each term of aOrderBy records a column of the ORDER BY clause.
7593**
7594** The colUsed field indicates which columns of the virtual table may be
7595** required by the current scan. Virtual table columns are numbered from
7596** zero in the order in which they appear within the CREATE TABLE statement
7597** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62),
7598** the corresponding bit is set within the colUsed mask if the column may be
7599** required by SQLite. If the table has at least 64 columns and any column
7600** to the right of the first 63 is required, then bit 63 of colUsed is also
7601** set. In other words, column iCol may be required if the expression
7602** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to
7603** non-zero.
7604**
7605** The [xBestIndex] method must fill aConstraintUsage[] with information
7606** about what parameters to pass to xFilter. ^If argvIndex>0 then
7607** the right-hand side of the corresponding aConstraint[] is evaluated
7608** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit
7609** is true, then the constraint is assumed to be fully handled by the
7610** virtual table and might not be checked again by the byte code.)^ ^(The
7611** aConstraintUsage[].omit flag is an optimization hint. When the omit flag
7612** is left in its default setting of false, the constraint will always be
7613** checked separately in byte code. If the omit flag is changed to true, then
7614** the constraint may or may not be checked in byte code. In other words,
7615** when the omit flag is true there is no guarantee that the constraint will
7616** not be checked again using byte code.)^
7617**
7618** ^The idxNum and idxStr values are recorded and passed into the
7619** [xFilter] method.
7620** ^[sqlite3_free()] is used to free idxStr if and only if
7621** needToFreeIdxStr is true.
7622**
7623** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
7624** the correct order to satisfy the ORDER BY clause so that no separate
7625** sorting step is required.
7626**
7627** ^The estimatedCost value is an estimate of the cost of a particular
7628** strategy. A cost of N indicates that the cost of the strategy is similar
7629** to a linear scan of an SQLite table with N rows. A cost of log(N)
7630** indicates that the expense of the operation is similar to that of a
7631** binary search on a unique indexed field of an SQLite table with N rows.
7632**
7633** ^The estimatedRows value is an estimate of the number of rows that
7634** will be returned by the strategy.
7635**
7636** The xBestIndex method may optionally populate the idxFlags field with a
7637** mask of SQLITE_INDEX_SCAN_* flags. One such flag is
7638** [SQLITE_INDEX_SCAN_HEX], which if set causes the [EXPLAIN QUERY PLAN]
7639** output to show the idxNum as hex instead of as decimal. Another flag is
7640** SQLITE_INDEX_SCAN_UNIQUE, which if set indicates that the query plan will
7641** return at most one row.
7642**
7643** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then
7644** SQLite also assumes that if a call to the xUpdate() method is made as
7645** part of the same statement to delete or update a virtual table row and the
7646** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback
7647** any database changes. In other words, if the xUpdate() returns
7648** SQLITE_CONSTRAINT, the database contents must be exactly as they were
7649** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not
7650** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by
7651** the xUpdate method are automatically rolled back by SQLite.
7652**
7653** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info
7654** structure for SQLite [version 3.8.2] ([dateof:3.8.2]).
7655** If a virtual table extension is
7656** used with an SQLite version earlier than 3.8.2, the results of attempting
7657** to read or write the estimatedRows field are undefined (but are likely
7658** to include crashing the application). The estimatedRows field should
7659** therefore only be used if [sqlite3_libversion_number()] returns a
7660** value greater than or equal to 3008002. Similarly, the idxFlags field
7661** was added for [version 3.9.0] ([dateof:3.9.0]).
7662** It may therefore only be used if
7663** sqlite3_libversion_number() returns a value greater than or equal to
7664** 3009000.
7665*/
7666struct sqlite3_index_info {
7667 /* Inputs */
7668 int nConstraint; /* Number of entries in aConstraint */
7669 struct sqlite3_index_constraint {
7670 int iColumn; /* Column constrained. -1 for ROWID */
7671 unsigned char op; /* Constraint operator */
7672 unsigned char usable; /* True if this constraint is usable */
7673 int iTermOffset; /* Used internally - xBestIndex should ignore */
7674 } *aConstraint; /* Table of WHERE clause constraints */
7675 int nOrderBy; /* Number of terms in the ORDER BY clause */
7676 struct sqlite3_index_orderby {
7677 int iColumn; /* Column number */
7678 unsigned char desc; /* True for DESC. False for ASC. */
7679 } *aOrderBy; /* The ORDER BY clause */
7680 /* Outputs */
7681 struct sqlite3_index_constraint_usage {
7682 int argvIndex; /* if >0, constraint is part of argv to xFilter */
7683 unsigned char omit; /* Do not code a test for this constraint */
7684 } *aConstraintUsage;
7685 int idxNum; /* Number used to identify the index */
7686 char *idxStr; /* String, possibly obtained from sqlite3_malloc */
7687 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */
7688 int orderByConsumed; /* True if output is already ordered */
7689 double estimatedCost; /* Estimated cost of using this index */
7690 /* Fields below are only available in SQLite 3.8.2 and later */
7691 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */
7692 /* Fields below are only available in SQLite 3.9.0 and later */
7693 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */
7694 /* Fields below are only available in SQLite 3.10.0 and later */
7695 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */
7696};
7697
7698/*
7699** CAPI3REF: Virtual Table Scan Flags
7700**
7701** Virtual table implementations are allowed to set the
7702** [sqlite3_index_info].idxFlags field to some combination of
7703** these bits.
7704*/
7705#define SQLITE_INDEX_SCAN_UNIQUE 0x00000001 /* Scan visits at most 1 row */
7706#define SQLITE_INDEX_SCAN_HEX 0x00000002 /* Display idxNum as hex */
7707 /* in EXPLAIN QUERY PLAN */
7708
7709/*
7710** CAPI3REF: Virtual Table Constraint Operator Codes
7711**
7712** These macros define the allowed values for the
7713** [sqlite3_index_info].aConstraint[].op field. Each value represents
7714** an operator that is part of a constraint term in the WHERE clause of
7715** a query that uses a [virtual table].
7716**
7717** ^The left-hand operand of the operator is given by the corresponding
7718** aConstraint[].iColumn field. ^An iColumn of -1 indicates the left-hand
7719** operand is the rowid.
7720** The SQLITE_INDEX_CONSTRAINT_LIMIT and SQLITE_INDEX_CONSTRAINT_OFFSET
7721** operators have no left-hand operand, and so for those operators the
7722** corresponding aConstraint[].iColumn is meaningless and should not be
7723** used.
7724**
7725** All operator values from SQLITE_INDEX_CONSTRAINT_FUNCTION through
7726** value 255 are reserved to represent functions that are overloaded
7727** by the [xFindFunction|xFindFunction method] of the virtual table
7728** implementation.
7729**
7730** The right-hand operands for each constraint might be accessible using
7731** the [sqlite3_vtab_rhs_value()] interface. Usually the right-hand
7732** operand is only available if it appears as a single constant literal
7733** in the input SQL. If the right-hand operand is another column or an
7734** expression (even a constant expression) or a parameter, then the
7735** sqlite3_vtab_rhs_value() probably will not be able to extract it.
7736** ^The SQLITE_INDEX_CONSTRAINT_ISNULL and
7737** SQLITE_INDEX_CONSTRAINT_ISNOTNULL operators have no right-hand operand
7738** and hence calls to sqlite3_vtab_rhs_value() for those operators will
7739** always return SQLITE_NOTFOUND.
7740**
7741** The collating sequence to be used for comparison can be found using
7742** the [sqlite3_vtab_collation()] interface. For most real-world virtual
7743** tables, the collating sequence of constraints does not matter (for example
7744** because the constraints are numeric) and so the sqlite3_vtab_collation()
7745** interface is not commonly needed.
7746*/
7747#define SQLITE_INDEX_CONSTRAINT_EQ 2
7748#define SQLITE_INDEX_CONSTRAINT_GT 4
7749#define SQLITE_INDEX_CONSTRAINT_LE 8
7750#define SQLITE_INDEX_CONSTRAINT_LT 16
7751#define SQLITE_INDEX_CONSTRAINT_GE 32
7752#define SQLITE_INDEX_CONSTRAINT_MATCH 64
7753#define SQLITE_INDEX_CONSTRAINT_LIKE 65
7754#define SQLITE_INDEX_CONSTRAINT_GLOB 66
7755#define SQLITE_INDEX_CONSTRAINT_REGEXP 67
7756#define SQLITE_INDEX_CONSTRAINT_NE 68
7757#define SQLITE_INDEX_CONSTRAINT_ISNOT 69
7758#define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70
7759#define SQLITE_INDEX_CONSTRAINT_ISNULL 71
7760#define SQLITE_INDEX_CONSTRAINT_IS 72
7761#define SQLITE_INDEX_CONSTRAINT_LIMIT 73
7762#define SQLITE_INDEX_CONSTRAINT_OFFSET 74
7763#define SQLITE_INDEX_CONSTRAINT_FUNCTION 150
7764
7765/*
7766** CAPI3REF: Register A Virtual Table Implementation
7767** METHOD: sqlite3
7768**
7769** ^These routines are used to register a new [virtual table module] name.
7770** ^Module names must be registered before
7771** creating a new [virtual table] using the module and before using a
7772** preexisting [virtual table] for the module.
7773**
7774** ^The module name is registered on the [database connection] specified
7775** by the first parameter. ^The name of the module is given by the
7776** second parameter. ^The third parameter is a pointer to
7777** the implementation of the [virtual table module]. ^The fourth
7778** parameter is an arbitrary client data pointer that is passed through
7779** into the [xCreate] and [xConnect] methods of the virtual table module
7780** when a new virtual table is being created or reinitialized.
7781**
7782** ^The sqlite3_create_module_v2() interface has a fifth parameter which
7783** is a pointer to a destructor for the pClientData. ^SQLite will
7784** invoke the destructor function (if it is not NULL) when SQLite
7785** no longer needs the pClientData pointer. ^The destructor will also
7786** be invoked if the call to sqlite3_create_module_v2() fails.
7787** ^The sqlite3_create_module()
7788** interface is equivalent to sqlite3_create_module_v2() with a NULL
7789** destructor.
7790**
7791** ^If the third parameter (the pointer to the sqlite3_module object) is
7792** NULL then no new module is created and any existing modules with the
7793** same name are dropped.
7794**
7795** See also: [sqlite3_drop_modules()]
7796*/
7797SQLITE_API int sqlite3_create_module(
7798 sqlite3 *db, /* SQLite connection to register module with */
7799 const char *zName, /* Name of the module */
7800 const sqlite3_module *p, /* Methods for the module */
7801 void *pClientData /* Client data for xCreate/xConnect */
7802);
7803SQLITE_API int sqlite3_create_module_v2(
7804 sqlite3 *db, /* SQLite connection to register module with */
7805 const char *zName, /* Name of the module */
7806 const sqlite3_module *p, /* Methods for the module */
7807 void *pClientData, /* Client data for xCreate/xConnect */
7808 void(*xDestroy)(void*) /* Module destructor function */
7809);
7810
7811/*
7812** CAPI3REF: Remove Unnecessary Virtual Table Implementations
7813** METHOD: sqlite3
7814**
7815** ^The sqlite3_drop_modules(D,L) interface removes all virtual
7816** table modules from database connection D except those named on list L.
7817** The L parameter must be either NULL or a pointer to an array of pointers
7818** to strings where the array is terminated by a single NULL pointer.
7819** ^If the L parameter is NULL, then all virtual table modules are removed.
7820**
7821** See also: [sqlite3_create_module()]
7822*/
7823SQLITE_API int sqlite3_drop_modules(
7824 sqlite3 *db, /* Remove modules from this connection */
7825 const char **azKeep /* Except, do not remove the ones named here */
7826);
7827
7828/*
7829** CAPI3REF: Virtual Table Instance Object
7830** KEYWORDS: sqlite3_vtab
7831**
7832** Every [virtual table module] implementation uses a subclass
7833** of this object to describe a particular instance
7834** of the [virtual table]. Each subclass will
7835** be tailored to the specific needs of the module implementation.
7836** The purpose of this superclass is to define certain fields that are
7837** common to all module implementations.
7838**
7839** ^Virtual tables methods can set an error message by assigning a
7840** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should
7841** take care that any prior string is freed by a call to [sqlite3_free()]
7842** prior to assigning a new string to zErrMsg. ^After the error message
7843** is delivered up to the client application, the string will be automatically
7844** freed by sqlite3_free() and the zErrMsg field will be zeroed.
7845*/
7846struct sqlite3_vtab {
7847 const sqlite3_module *pModule; /* The module for this virtual table */
7848 int nRef; /* Number of open cursors */
7849 char *zErrMsg; /* Error message from sqlite3_mprintf() */
7850 /* Virtual table implementations will typically add additional fields */
7851};
7852
7853/*
7854** CAPI3REF: Virtual Table Cursor Object
7855** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
7856**
7857** Every [virtual table module] implementation uses a subclass of the
7858** following structure to describe cursors that point into the
7859** [virtual table] and are used
7860** to loop through the virtual table. Cursors are created using the
7861** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
7862** by the [sqlite3_module.xClose | xClose] method. Cursors are used
7863** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
7864** of the module. Each module implementation will define
7865** the content of a cursor structure to suit its own needs.
7866**
7867** This superclass exists in order to define fields of the cursor that
7868** are common to all implementations.
7869*/
7870struct sqlite3_vtab_cursor {
7871 sqlite3_vtab *pVtab; /* Virtual table of this cursor */
7872 /* Virtual table implementations will typically add additional fields */
7873};
7874
7875/*
7876** CAPI3REF: Declare The Schema Of A Virtual Table
7877**
7878** ^The [xCreate] and [xConnect] methods of a
7879** [virtual table module] call this interface
7880** to declare the format (the names and datatypes of the columns) of
7881** the virtual tables they implement.
7882*/
7883SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL);
7884
7885/*
7886** CAPI3REF: Overload A Function For A Virtual Table
7887** METHOD: sqlite3
7888**
7889** ^(Virtual tables can provide alternative implementations of functions
7890** using the [xFindFunction] method of the [virtual table module].
7891** But global versions of those functions
7892** must exist in order to be overloaded.)^
7893**
7894** ^(This API makes sure a global version of a function with a particular
7895** name and number of parameters exists. If no such function exists
7896** before this API is called, a new function is created.)^ ^The implementation
7897** of the new function always causes an exception to be thrown. So
7898** the new function is not good for anything by itself. Its only
7899** purpose is to be a placeholder function that can be overloaded
7900** by a [virtual table].
7901*/
7902SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
7903
7904/*
7905** CAPI3REF: A Handle To An Open BLOB
7906** KEYWORDS: {BLOB handle} {BLOB handles}
7907**
7908** An instance of this object represents an open BLOB on which
7909** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
7910** ^Objects of this type are created by [sqlite3_blob_open()]
7911** and destroyed by [sqlite3_blob_close()].
7912** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
7913** can be used to read or write small subsections of the BLOB.
7914** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
7915*/
7916typedef struct sqlite3_blob sqlite3_blob;
7917
7918/*
7919** CAPI3REF: Open A BLOB For Incremental I/O
7920** METHOD: sqlite3
7921** CONSTRUCTOR: sqlite3_blob
7922**
7923** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
7924** in row iRow, column zColumn, table zTable in database zDb;
7925** in other words, the same BLOB that would be selected by:
7926**
7927** <pre>
7928** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
7929** </pre>)^
7930**
7931** ^(Parameter zDb is not the filename that contains the database, but
7932** rather the symbolic name of the database. For attached databases, this is
7933** the name that appears after the AS keyword in the [ATTACH] statement.
7934** For the main database file, the database name is "main". For TEMP
7935** tables, the database name is "temp".)^
7936**
7937** ^If the flags parameter is non-zero, then the BLOB is opened for read
7938** and write access. ^If the flags parameter is zero, the BLOB is opened for
7939** read-only access.
7940**
7941** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored
7942** in *ppBlob. Otherwise an [error code] is returned and, unless the error
7943** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided
7944** the API is not misused, it is always safe to call [sqlite3_blob_close()]
7945** on *ppBlob after this function returns.
7946**
7947** This function fails with SQLITE_ERROR if any of the following are true:
7948** <ul>
7949** <li> ^(Database zDb does not exist)^,
7950** <li> ^(Table zTable does not exist within database zDb)^,
7951** <li> ^(Table zTable is a WITHOUT ROWID table)^,
7952** <li> ^(Column zColumn does not exist)^,
7953** <li> ^(Row iRow is not present in the table)^,
7954** <li> ^(The specified column of row iRow contains a value that is not
7955** a TEXT or BLOB value)^,
7956** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE
7957** constraint and the blob is being opened for read/write access)^,
7958** <li> ^([foreign key constraints | Foreign key constraints] are enabled,
7959** column zColumn is part of a [child key] definition and the blob is
7960** being opened for read/write access)^.
7961** </ul>
7962**
7963** ^Unless it returns SQLITE_MISUSE, this function sets the
7964** [database connection] error code and message accessible via
7965** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
7966**
7967** A BLOB referenced by sqlite3_blob_open() may be read using the
7968** [sqlite3_blob_read()] interface and modified by using
7969** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a
7970** different row of the same table using the [sqlite3_blob_reopen()]
7971** interface. However, the column, table, or database of a [BLOB handle]
7972** cannot be changed after the [BLOB handle] is opened.
7973**
7974** ^(If the row that a BLOB handle points to is modified by an
7975** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
7976** then the BLOB handle is marked as "expired".
7977** This is true if any column of the row is changed, even a column
7978** other than the one the BLOB handle is open on.)^
7979** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
7980** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
7981** ^(Changes written into a BLOB prior to the BLOB expiring are not
7982** rolled back by the expiration of the BLOB. Such changes will eventually
7983** commit if the transaction continues to completion.)^
7984**
7985** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
7986** the opened blob. ^The size of a blob may not be changed by this
7987** interface. Use the [UPDATE] SQL command to change the size of a
7988** blob.
7989**
7990** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
7991** and the built-in [zeroblob] SQL function may be used to create a
7992** zero-filled blob to read or write using the incremental-blob interface.
7993**
7994** To avoid a resource leak, every open [BLOB handle] should eventually
7995** be released by a call to [sqlite3_blob_close()].
7996**
7997** See also: [sqlite3_blob_close()],
7998** [sqlite3_blob_reopen()], [sqlite3_blob_read()],
7999** [sqlite3_blob_bytes()], [sqlite3_blob_write()].
8000*/
8001SQLITE_API int sqlite3_blob_open(
8002 sqlite3*,
8003 const char *zDb,
8004 const char *zTable,
8005 const char *zColumn,
8006 sqlite3_int64 iRow,
8007 int flags,
8008 sqlite3_blob **ppBlob
8009);
8010
8011/*
8012** CAPI3REF: Move a BLOB Handle to a New Row
8013** METHOD: sqlite3_blob
8014**
8015** ^This function is used to move an existing [BLOB handle] so that it points
8016** to a different row of the same database table. ^The new row is identified
8017** by the rowid value passed as the second argument. Only the row can be
8018** changed. ^The database, table and column on which the blob handle is open
8019** remain the same. Moving an existing [BLOB handle] to a new row is
8020** faster than closing the existing handle and opening a new one.
8021**
8022** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
8023** it must exist and there must be either a blob or text value stored in
8024** the nominated column.)^ ^If the new row is not present in the table, or if
8025** it does not contain a blob or text value, or if another error occurs, an
8026** SQLite error code is returned and the blob handle is considered aborted.
8027** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or
8028** [sqlite3_blob_reopen()] on an aborted blob handle immediately return
8029** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
8030** always returns zero.
8031**
8032** ^This function sets the database handle error code and message.
8033*/
8034SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
8035
8036/*
8037** CAPI3REF: Close A BLOB Handle
8038** DESTRUCTOR: sqlite3_blob
8039**
8040** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed
8041** unconditionally. Even if this routine returns an error code, the
8042** handle is still closed.)^
8043**
8044** ^If the blob handle being closed was opened for read-write access, and if
8045** the database is in auto-commit mode and there are no other open read-write
8046** blob handles or active write statements, the current transaction is
8047** committed. ^If an error occurs while committing the transaction, an error
8048** code is returned and the transaction rolled back.
8049**
8050** Calling this function with an argument that is not a NULL pointer or an
8051** open blob handle results in undefined behavior. ^Calling this routine
8052** with a null pointer (such as would be returned by a failed call to
8053** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function
8054** is passed a valid open blob handle, the values returned by the
8055** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning.
8056*/
8057SQLITE_API int sqlite3_blob_close(sqlite3_blob *);
8058
8059/*
8060** CAPI3REF: Return The Size Of An Open BLOB
8061** METHOD: sqlite3_blob
8062**
8063** ^Returns the size in bytes of the BLOB accessible via the
8064** successfully opened [BLOB handle] in its only argument. ^The
8065** incremental blob I/O routines can only read or overwrite existing
8066** blob content; they cannot change the size of a blob.
8067**
8068** This routine only works on a [BLOB handle] which has been created
8069** by a prior successful call to [sqlite3_blob_open()] and which has not
8070** been closed by [sqlite3_blob_close()]. Passing any other pointer in
8071** to this routine results in undefined and probably undesirable behavior.
8072*/
8073SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *);
8074
8075/*
8076** CAPI3REF: Read Data From A BLOB Incrementally
8077** METHOD: sqlite3_blob
8078**
8079** ^(This function is used to read data from an open [BLOB handle] into a
8080** caller-supplied buffer. N bytes of data are copied into buffer Z
8081** from the open BLOB, starting at offset iOffset.)^
8082**
8083** ^If offset iOffset is less than N bytes from the end of the BLOB,
8084** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is
8085** less than zero, [SQLITE_ERROR] is returned and no data is read.
8086** ^The size of the blob (and hence the maximum value of N+iOffset)
8087** can be determined using the [sqlite3_blob_bytes()] interface.
8088**
8089** ^An attempt to read from an expired [BLOB handle] fails with an
8090** error code of [SQLITE_ABORT].
8091**
8092** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
8093** Otherwise, an [error code] or an [extended error code] is returned.)^
8094**
8095** This routine only works on a [BLOB handle] which has been created
8096** by a prior successful call to [sqlite3_blob_open()] and which has not
8097** been closed by [sqlite3_blob_close()]. Passing any other pointer in
8098** to this routine results in undefined and probably undesirable behavior.
8099**
8100** See also: [sqlite3_blob_write()].
8101*/
8102SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
8103
8104/*
8105** CAPI3REF: Write Data Into A BLOB Incrementally
8106** METHOD: sqlite3_blob
8107**
8108** ^(This function is used to write data into an open [BLOB handle] from a
8109** caller-supplied buffer. N bytes of data are copied from the buffer Z
8110** into the open BLOB, starting at offset iOffset.)^
8111**
8112** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
8113** Otherwise, an [error code] or an [extended error code] is returned.)^
8114** ^Unless SQLITE_MISUSE is returned, this function sets the
8115** [database connection] error code and message accessible via
8116** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
8117**
8118** ^If the [BLOB handle] passed as the first argument was not opened for
8119** writing (the flags parameter to [sqlite3_blob_open()] was zero),
8120** this function returns [SQLITE_READONLY].
8121**
8122** This function may only modify the contents of the BLOB; it is
8123** not possible to increase the size of a BLOB using this API.
8124** ^If offset iOffset is less than N bytes from the end of the BLOB,
8125** [SQLITE_ERROR] is returned and no data is written. The size of the
8126** BLOB (and hence the maximum value of N+iOffset) can be determined
8127** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less
8128** than zero [SQLITE_ERROR] is returned and no data is written.
8129**
8130** ^An attempt to write to an expired [BLOB handle] fails with an
8131** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred
8132** before the [BLOB handle] expired are not rolled back by the
8133** expiration of the handle, though of course those changes might
8134** have been overwritten by the statement that expired the BLOB handle
8135** or by other independent statements.
8136**
8137** This routine only works on a [BLOB handle] which has been created
8138** by a prior successful call to [sqlite3_blob_open()] and which has not
8139** been closed by [sqlite3_blob_close()]. Passing any other pointer in
8140** to this routine results in undefined and probably undesirable behavior.
8141**
8142** See also: [sqlite3_blob_read()].
8143*/
8144SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
8145
8146/*
8147** CAPI3REF: Virtual File System Objects
8148**
8149** A virtual filesystem (VFS) is an [sqlite3_vfs] object
8150** that SQLite uses to interact
8151** with the underlying operating system. Most SQLite builds come with a
8152** single default VFS that is appropriate for the host computer.
8153** New VFSes can be registered and existing VFSes can be unregistered.
8154** The following interfaces are provided.
8155**
8156** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
8157** ^Names are case sensitive.
8158** ^Names are zero-terminated UTF-8 strings.
8159** ^If there is no match, a NULL pointer is returned.
8160** ^If zVfsName is NULL then the default VFS is returned.
8161**
8162** ^New VFSes are registered with sqlite3_vfs_register().
8163** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
8164** ^The same VFS can be registered multiple times without injury.
8165** ^To make an existing VFS into the default VFS, register it again
8166** with the makeDflt flag set. If two different VFSes with the
8167** same name are registered, the behavior is undefined. If a
8168** VFS is registered with a name that is NULL or an empty string,
8169** then the behavior is undefined.
8170**
8171** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
8172** ^(If the default VFS is unregistered, another VFS is chosen as
8173** the default. The choice for the new VFS is arbitrary.)^
8174*/
8175SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
8176SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
8177SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
8178
8179/*
8180** CAPI3REF: Mutexes
8181**
8182** The SQLite core uses these routines for thread
8183** synchronization. Though they are intended for internal
8184** use by SQLite, code that links against SQLite is
8185** permitted to use any of these routines.
8186**
8187** The SQLite source code contains multiple implementations
8188** of these mutex routines. An appropriate implementation
8189** is selected automatically at compile-time. The following
8190** implementations are available in the SQLite core:
8191**
8192** <ul>
8193** <li> SQLITE_MUTEX_PTHREADS
8194** <li> SQLITE_MUTEX_W32
8195** <li> SQLITE_MUTEX_NOOP
8196** </ul>
8197**
8198** The SQLITE_MUTEX_NOOP implementation is a set of routines
8199** that does no real locking and is appropriate for use in
8200** a single-threaded application. The SQLITE_MUTEX_PTHREADS and
8201** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix
8202** and Windows.
8203**
8204** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
8205** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
8206** implementation is included with the library. In this case the
8207** application must supply a custom mutex implementation using the
8208** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
8209** before calling sqlite3_initialize() or any other public sqlite3_
8210** function that calls sqlite3_initialize().
8211**
8212** ^The sqlite3_mutex_alloc() routine allocates a new
8213** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc()
8214** routine returns NULL if it is unable to allocate the requested
8215** mutex. The argument to sqlite3_mutex_alloc() must be one of these
8216** integer constants:
8217**
8218** <ul>
8219** <li> SQLITE_MUTEX_FAST
8220** <li> SQLITE_MUTEX_RECURSIVE
8221** <li> SQLITE_MUTEX_STATIC_MAIN
8222** <li> SQLITE_MUTEX_STATIC_MEM
8223** <li> SQLITE_MUTEX_STATIC_OPEN
8224** <li> SQLITE_MUTEX_STATIC_PRNG
8225** <li> SQLITE_MUTEX_STATIC_LRU
8226** <li> SQLITE_MUTEX_STATIC_PMEM
8227** <li> SQLITE_MUTEX_STATIC_APP1
8228** <li> SQLITE_MUTEX_STATIC_APP2
8229** <li> SQLITE_MUTEX_STATIC_APP3
8230** <li> SQLITE_MUTEX_STATIC_VFS1
8231** <li> SQLITE_MUTEX_STATIC_VFS2
8232** <li> SQLITE_MUTEX_STATIC_VFS3
8233** </ul>
8234**
8235** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
8236** cause sqlite3_mutex_alloc() to create
8237** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
8238** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
8239** The mutex implementation does not need to make a distinction
8240** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
8241** not want to. SQLite will only request a recursive mutex in
8242** cases where it really needs one. If a faster non-recursive mutex
8243** implementation is available on the host platform, the mutex subsystem
8244** might return such a mutex in response to SQLITE_MUTEX_FAST.
8245**
8246** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
8247** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
8248** a pointer to a static preexisting mutex. ^Nine static mutexes are
8249** used by the current version of SQLite. Future versions of SQLite
8250** may add additional static mutexes. Static mutexes are for internal
8251** use by SQLite only. Applications that use SQLite mutexes should
8252** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
8253** SQLITE_MUTEX_RECURSIVE.
8254**
8255** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
8256** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
8257** returns a different mutex on every call. ^For the static
8258** mutex types, the same mutex is returned on every call that has
8259** the same type number.
8260**
8261** ^The sqlite3_mutex_free() routine deallocates a previously
8262** allocated dynamic mutex. Attempting to deallocate a static
8263** mutex results in undefined behavior.
8264**
8265** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
8266** to enter a mutex. ^If another thread is already within the mutex,
8267** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
8268** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
8269** upon successful entry. ^(Mutexes created using
8270** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
8271** In such cases, the
8272** mutex must be exited an equal number of times before another thread
8273** can enter.)^ If the same thread tries to enter any mutex other
8274** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined.
8275**
8276** ^(Some systems (for example, Windows 95) do not support the operation
8277** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try()
8278** will always return SQLITE_BUSY. In most cases the SQLite core only uses
8279** sqlite3_mutex_try() as an optimization, so this is acceptable
8280** behavior. The exceptions are unix builds that set the
8281** SQLITE_ENABLE_SETLK_TIMEOUT build option. In that case a working
8282** sqlite3_mutex_try() is required.)^
8283**
8284** ^The sqlite3_mutex_leave() routine exits a mutex that was
8285** previously entered by the same thread. The behavior
8286** is undefined if the mutex is not currently entered by the
8287** calling thread or is not currently allocated.
8288**
8289** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(),
8290** sqlite3_mutex_leave(), or sqlite3_mutex_free() is a NULL pointer,
8291** then any of the four routines behaves as a no-op.
8292**
8293** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
8294*/
8295SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int);
8296SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*);
8297SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*);
8298SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*);
8299SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*);
8300
8301/*
8302** CAPI3REF: Mutex Methods Object
8303**
8304** An instance of this structure defines the low-level routines
8305** used to allocate and use mutexes.
8306**
8307** Usually, the default mutex implementations provided by SQLite are
8308** sufficient, however the application has the option of substituting a custom
8309** implementation for specialized deployments or systems for which SQLite
8310** does not provide a suitable implementation. In this case, the application
8311** creates and populates an instance of this structure to pass
8312** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
8313** Additionally, an instance of this structure can be used as an
8314** output variable when querying the system for the current mutex
8315** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
8316**
8317** ^The xMutexInit method defined by this structure is invoked as
8318** part of system initialization by the sqlite3_initialize() function.
8319** ^The xMutexInit routine is called by SQLite exactly once for each
8320** effective call to [sqlite3_initialize()].
8321**
8322** ^The xMutexEnd method defined by this structure is invoked as
8323** part of system shutdown by the sqlite3_shutdown() function. The
8324** implementation of this method is expected to release all outstanding
8325** resources obtained by the mutex methods implementation, especially
8326** those obtained by the xMutexInit method. ^The xMutexEnd()
8327** interface is invoked exactly once for each call to [sqlite3_shutdown()].
8328**
8329** ^(The remaining seven methods defined by this structure (xMutexAlloc,
8330** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
8331** xMutexNotheld) implement the following interfaces (respectively):
8332**
8333** <ul>
8334** <li> [sqlite3_mutex_alloc()] </li>
8335** <li> [sqlite3_mutex_free()] </li>
8336** <li> [sqlite3_mutex_enter()] </li>
8337** <li> [sqlite3_mutex_try()] </li>
8338** <li> [sqlite3_mutex_leave()] </li>
8339** <li> [sqlite3_mutex_held()] </li>
8340** <li> [sqlite3_mutex_notheld()] </li>
8341** </ul>)^
8342**
8343** The only difference is that the public sqlite3_XXX functions enumerated
8344** above silently ignore any invocations that pass a NULL pointer instead
8345** of a valid mutex handle. The implementations of the methods defined
8346** by this structure are not required to handle this case. The results
8347** of passing a NULL pointer instead of a valid mutex handle are undefined
8348** (i.e. it is acceptable to provide an implementation that segfaults if
8349** it is passed a NULL pointer).
8350**
8351** The xMutexInit() method must be threadsafe. It must be harmless to
8352** invoke xMutexInit() multiple times within the same process and without
8353** intervening calls to xMutexEnd(). Second and subsequent calls to
8354** xMutexInit() must be no-ops.
8355**
8356** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
8357** and its associates). Similarly, xMutexAlloc() must not use SQLite memory
8358** allocation for a static mutex. ^However xMutexAlloc() may use SQLite
8359** memory allocation for a fast or recursive mutex.
8360**
8361** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
8362** called, but only if the prior call to xMutexInit returned SQLITE_OK.
8363** If xMutexInit fails in any way, it is expected to clean up after itself
8364** prior to returning.
8365*/
8366typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
8367struct sqlite3_mutex_methods {
8368 int (*xMutexInit)(void);
8369 int (*xMutexEnd)(void);
8370 sqlite3_mutex *(*xMutexAlloc)(int);
8371 void (*xMutexFree)(sqlite3_mutex *);
8372 void (*xMutexEnter)(sqlite3_mutex *);
8373 int (*xMutexTry)(sqlite3_mutex *);
8374 void (*xMutexLeave)(sqlite3_mutex *);
8375 int (*xMutexHeld)(sqlite3_mutex *);
8376 int (*xMutexNotheld)(sqlite3_mutex *);
8377};
8378
8379/*
8380** CAPI3REF: Mutex Verification Routines
8381**
8382** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
8383** are intended for use inside assert() statements. The SQLite core
8384** never uses these routines except inside an assert() and applications
8385** are advised to follow the lead of the core. The SQLite core only
8386** provides implementations for these routines when it is compiled
8387** with the SQLITE_DEBUG flag. External mutex implementations
8388** are only required to provide these routines if SQLITE_DEBUG is
8389** defined and if NDEBUG is not defined.
8390**
8391** These routines should return true if the mutex in their argument
8392** is held or not held, respectively, by the calling thread.
8393**
8394** The implementation is not required to provide versions of these
8395** routines that actually work. If the implementation does not provide working
8396** versions of these routines, it should at least provide stubs that always
8397** return true so that one does not get spurious assertion failures.
8398**
8399** If the argument to sqlite3_mutex_held() is a NULL pointer then
8400** the routine should return 1. This seems counter-intuitive since
8401** clearly the mutex cannot be held if it does not exist. But
8402** the reason the mutex does not exist is because the build is not
8403** using mutexes. And we do not want the assert() containing the
8404** call to sqlite3_mutex_held() to fail, so a non-zero return is
8405** the appropriate thing to do. The sqlite3_mutex_notheld()
8406** interface should also return 1 when given a NULL pointer.
8407*/
8408#ifndef NDEBUG
8409SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*);
8410SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);
8411#endif
8412
8413/*
8414** CAPI3REF: Mutex Types
8415**
8416** The [sqlite3_mutex_alloc()] interface takes a single argument
8417** which is one of these integer constants.
8418**
8419** The set of static mutexes may change from one SQLite release to the
8420** next. Applications that override the built-in mutex logic must be
8421** prepared to accommodate additional static mutexes.
8422*/
8423#define SQLITE_MUTEX_FAST 0
8424#define SQLITE_MUTEX_RECURSIVE 1
8425#define SQLITE_MUTEX_STATIC_MAIN 2
8426#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */
8427#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */
8428#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */
8429#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */
8430#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */
8431#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */
8432#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */
8433#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */
8434#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */
8435#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */
8436#define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */
8437#define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */
8438#define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */
8439
8440/* Legacy compatibility: */
8441#define SQLITE_MUTEX_STATIC_MASTER 2
8442
8443
8444/*
8445** CAPI3REF: Retrieve the mutex for a database connection
8446** METHOD: sqlite3
8447**
8448** ^This interface returns a pointer to the [sqlite3_mutex] object that
8449** serializes access to the [database connection] given in the argument
8450** when the [threading mode] is Serialized.
8451** ^If the [threading mode] is Single-thread or Multi-thread then this
8452** routine returns a NULL pointer.
8453*/
8454SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*);
8455
8456/*
8457** CAPI3REF: Low-Level Control Of Database Files
8458** METHOD: sqlite3
8459** KEYWORDS: {file control}
8460**
8461** ^The [sqlite3_file_control()] interface makes a direct call to the
8462** xFileControl method for the [sqlite3_io_methods] object associated
8463** with a particular database identified by the second argument. ^The
8464** name of the database is "main" for the main database or "temp" for the
8465** TEMP database, or the name that appears after the AS keyword for
8466** databases that are added using the [ATTACH] SQL command.
8467** ^A NULL pointer can be used in place of "main" to refer to the
8468** main database file.
8469** ^The third and fourth parameters to this routine
8470** are passed directly through to the second and third parameters of
8471** the xFileControl method. ^The return value of the xFileControl
8472** method becomes the return value of this routine.
8473**
8474** A few opcodes for [sqlite3_file_control()] are handled directly
8475** by the SQLite core and never invoke the
8476** sqlite3_io_methods.xFileControl method.
8477** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes
8478** a pointer to the underlying [sqlite3_file] object to be written into
8479** the space pointed to by the 4th parameter. The
8480** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns
8481** the [sqlite3_file] object associated with the journal file instead of
8482** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns
8483** a pointer to the underlying [sqlite3_vfs] object for the file.
8484** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter
8485** from the pager.
8486**
8487** ^If the second parameter (zDbName) does not match the name of any
8488** open database file, then SQLITE_ERROR is returned. ^This error
8489** code is not remembered and will not be recalled by [sqlite3_errcode()]
8490** or [sqlite3_errmsg()]. The underlying xFileControl method might
8491** also return SQLITE_ERROR. There is no way to distinguish between
8492** an incorrect zDbName and an SQLITE_ERROR return from the underlying
8493** xFileControl method.
8494**
8495** See also: [file control opcodes]
8496*/
8497SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
8498
8499/*
8500** CAPI3REF: Testing Interface
8501**
8502** ^The sqlite3_test_control() interface is used to read out internal
8503** state of SQLite and to inject faults into SQLite for testing
8504** purposes. ^The first parameter is an operation code that determines
8505** the number, meaning, and operation of all subsequent parameters.
8506**
8507** This interface is not for use by applications. It exists solely
8508** for verifying the correct operation of the SQLite library. Depending
8509** on how the SQLite library is compiled, this interface might not exist.
8510**
8511** The details of the operation codes, their meanings, the parameters
8512** they take, and what they do are all subject to change without notice.
8513** Unlike most of the SQLite API, this function is not guaranteed to
8514** operate consistently from one release to the next.
8515*/
8516SQLITE_API int sqlite3_test_control(int op, ...);
8517
8518/*
8519** CAPI3REF: Testing Interface Operation Codes
8520**
8521** These constants are the valid operation code parameters used
8522** as the first argument to [sqlite3_test_control()].
8523**
8524** These parameters and their meanings are subject to change
8525** without notice. These values are for testing purposes only.
8526** Applications should not use any of these parameters or the
8527** [sqlite3_test_control()] interface.
8528*/
8529#define SQLITE_TESTCTRL_FIRST 5
8530#define SQLITE_TESTCTRL_PRNG_SAVE 5
8531#define SQLITE_TESTCTRL_PRNG_RESTORE 6
8532#define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */
8533#define SQLITE_TESTCTRL_FK_NO_ACTION 7
8534#define SQLITE_TESTCTRL_BITVEC_TEST 8
8535#define SQLITE_TESTCTRL_FAULT_INSTALL 9
8536#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10
8537#define SQLITE_TESTCTRL_PENDING_BYTE 11
8538#define SQLITE_TESTCTRL_ASSERT 12
8539#define SQLITE_TESTCTRL_ALWAYS 13
8540#define SQLITE_TESTCTRL_RESERVE 14 /* NOT USED */
8541#define SQLITE_TESTCTRL_JSON_SELFCHECK 14
8542#define SQLITE_TESTCTRL_OPTIMIZATIONS 15
8543#define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */
8544#define SQLITE_TESTCTRL_GETOPT 16
8545#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */
8546#define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17
8547#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18
8548#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */
8549#define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19
8550#define SQLITE_TESTCTRL_NEVER_CORRUPT 20
8551#define SQLITE_TESTCTRL_VDBE_COVERAGE 21
8552#define SQLITE_TESTCTRL_BYTEORDER 22
8553#define SQLITE_TESTCTRL_ISINIT 23
8554#define SQLITE_TESTCTRL_SORTER_MMAP 24
8555#define SQLITE_TESTCTRL_IMPOSTER 25
8556#define SQLITE_TESTCTRL_PARSER_COVERAGE 26
8557#define SQLITE_TESTCTRL_RESULT_INTREAL 27
8558#define SQLITE_TESTCTRL_PRNG_SEED 28
8559#define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29
8560#define SQLITE_TESTCTRL_SEEK_COUNT 30
8561#define SQLITE_TESTCTRL_TRACEFLAGS 31
8562#define SQLITE_TESTCTRL_TUNE 32
8563#define SQLITE_TESTCTRL_LOGEST 33
8564#define SQLITE_TESTCTRL_USELONGDOUBLE 34 /* NOT USED */
8565#define SQLITE_TESTCTRL_LAST 34 /* Largest TESTCTRL */
8566
8567/*
8568** CAPI3REF: SQL Keyword Checking
8569**
8570** These routines provide access to the set of SQL language keywords
8571** recognized by SQLite. Applications can use these routines to determine
8572** whether or not a specific identifier needs to be escaped (for example,
8573** by enclosing in double-quotes) so as not to confuse the parser.
8574**
8575** The sqlite3_keyword_count() interface returns the number of distinct
8576** keywords understood by SQLite.
8577**
8578** The sqlite3_keyword_name(N,Z,L) interface finds the 0-based N-th keyword and
8579** makes *Z point to that keyword expressed as UTF8 and writes the number
8580** of bytes in the keyword into *L. The string that *Z points to is not
8581** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns
8582** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z
8583** or L are NULL or invalid pointers then calls to
8584** sqlite3_keyword_name(N,Z,L) result in undefined behavior.
8585**
8586** The sqlite3_keyword_check(Z,L) interface checks to see whether or not
8587** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero
8588** if it is and zero if not.
8589**
8590** The parser used by SQLite is forgiving. It is often possible to use
8591** a keyword as an identifier as long as such use does not result in a
8592** parsing ambiguity. For example, the statement
8593** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and
8594** creates a new table named "BEGIN" with three columns named
8595** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid
8596** using keywords as identifiers. Common techniques used to avoid keyword
8597** name collisions include:
8598** <ul>
8599** <li> Put all identifier names inside double-quotes. This is the official
8600** SQL way to escape identifier names.
8601** <li> Put identifier names inside [...]. This is not standard SQL,
8602** but it is what SQL Server does and so lots of programmers use this
8603** technique.
8604** <li> Begin every identifier with the letter "Z" as no SQL keywords start
8605** with "Z".
8606** <li> Include a digit somewhere in every identifier name.
8607** </ul>
8608**
8609** Note that the number of keywords understood by SQLite can depend on
8610** compile-time options. For example, "VACUUM" is not a keyword if
8611** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also,
8612** new keywords may be added to future releases of SQLite.
8613*/
8614SQLITE_API int sqlite3_keyword_count(void);
8615SQLITE_API int sqlite3_keyword_name(int,const char**,int*);
8616SQLITE_API int sqlite3_keyword_check(const char*,int);
8617
8618/*
8619** CAPI3REF: Dynamic String Object
8620** KEYWORDS: {dynamic string}
8621**
8622** An instance of the sqlite3_str object contains a dynamically-sized
8623** string under construction.
8624**
8625** The lifecycle of an sqlite3_str object is as follows:
8626** <ol>
8627** <li> ^The sqlite3_str object is created using [sqlite3_str_new()].
8628** <li> ^Text is appended to the sqlite3_str object using various
8629** methods, such as [sqlite3_str_appendf()].
8630** <li> ^The sqlite3_str object is destroyed and the string it created
8631** is returned using the [sqlite3_str_finish()] interface.
8632** </ol>
8633*/
8634typedef struct sqlite3_str sqlite3_str;
8635
8636/*
8637** CAPI3REF: Create A New Dynamic String Object
8638** CONSTRUCTOR: sqlite3_str
8639**
8640** ^The [sqlite3_str_new(D)] interface allocates and initializes
8641** a new [sqlite3_str] object. To avoid memory leaks, the object returned by
8642** [sqlite3_str_new()] must be freed by a subsequent call to
8643** [sqlite3_str_finish(X)].
8644**
8645** ^The [sqlite3_str_new(D)] interface always returns a pointer to a
8646** valid [sqlite3_str] object, though in the event of an out-of-memory
8647** error the returned object might be a special singleton that will
8648** silently reject new text, always return SQLITE_NOMEM from
8649** [sqlite3_str_errcode()], always return 0 for
8650** [sqlite3_str_length()], and always return NULL from
8651** [sqlite3_str_finish(X)]. It is always safe to use the value
8652** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter
8653** to any of the other [sqlite3_str] methods.
8654**
8655** The D parameter to [sqlite3_str_new(D)] may be NULL. If the
8656** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum
8657** length of the string contained in the [sqlite3_str] object will be
8658** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead
8659** of [SQLITE_MAX_LENGTH].
8660*/
8661SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*);
8662
8663/*
8664** CAPI3REF: Finalize A Dynamic String
8665** DESTRUCTOR: sqlite3_str
8666**
8667** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X
8668** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()]
8669** that contains the constructed string. The calling application should
8670** pass the returned value to [sqlite3_free()] to avoid a memory leak.
8671** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any
8672** errors were encountered during construction of the string. ^The
8673** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the
8674** string in [sqlite3_str] object X is zero bytes long.
8675*/
8676SQLITE_API char *sqlite3_str_finish(sqlite3_str*);
8677
8678/*
8679** CAPI3REF: Add Content To A Dynamic String
8680** METHOD: sqlite3_str
8681**
8682** These interfaces add content to an sqlite3_str object previously obtained
8683** from [sqlite3_str_new()].
8684**
8685** ^The [sqlite3_str_appendf(X,F,...)] and
8686** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf]
8687** functionality of SQLite to append formatted text onto the end of
8688** [sqlite3_str] object X.
8689**
8690** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S
8691** onto the end of the [sqlite3_str] object X. N must be non-negative.
8692** S must contain at least N non-zero bytes of content. To append a
8693** zero-terminated string in its entirety, use the [sqlite3_str_appendall()]
8694** method instead.
8695**
8696** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of
8697** zero-terminated string S onto the end of [sqlite3_str] object X.
8698**
8699** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the
8700** single-byte character C onto the end of [sqlite3_str] object X.
8701** ^This method can be used, for example, to add whitespace indentation.
8702**
8703** ^The [sqlite3_str_reset(X)] method resets the string under construction
8704** inside [sqlite3_str] object X back to zero bytes in length.
8705**
8706** These methods do not return a result code. ^If an error occurs, that fact
8707** is recorded in the [sqlite3_str] object and can be recovered by a
8708** subsequent call to [sqlite3_str_errcode(X)].
8709*/
8710SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...);
8711SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list);
8712SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N);
8713SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn);
8714SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C);
8715SQLITE_API void sqlite3_str_reset(sqlite3_str*);
8716
8717/*
8718** CAPI3REF: Status Of A Dynamic String
8719** METHOD: sqlite3_str
8720**
8721** These interfaces return the current status of an [sqlite3_str] object.
8722**
8723** ^If any prior errors have occurred while constructing the dynamic string
8724** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return
8725** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns
8726** [SQLITE_NOMEM] following any out-of-memory error, or
8727** [SQLITE_TOOBIG] if the size of the dynamic string exceeds
8728** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors.
8729**
8730** ^The [sqlite3_str_length(X)] method returns the current length, in bytes,
8731** of the dynamic string under construction in [sqlite3_str] object X.
8732** ^The length returned by [sqlite3_str_length(X)] does not include the
8733** zero-termination byte.
8734**
8735** ^The [sqlite3_str_value(X)] method returns a pointer to the current
8736** content of the dynamic string under construction in X. The value
8737** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X
8738** and might be freed or altered by any subsequent method on the same
8739** [sqlite3_str] object. Applications must not use the pointer returned by
8740** [sqlite3_str_value(X)] after any subsequent method call on the same
8741** object. ^Applications may change the content of the string returned
8742** by [sqlite3_str_value(X)] as long as they do not write into any bytes
8743** outside the range of 0 to [sqlite3_str_length(X)] and do not read or
8744** write any byte after any subsequent sqlite3_str method call.
8745*/
8746SQLITE_API int sqlite3_str_errcode(sqlite3_str*);
8747SQLITE_API int sqlite3_str_length(sqlite3_str*);
8748SQLITE_API char *sqlite3_str_value(sqlite3_str*);
8749
8750/*
8751** CAPI3REF: SQLite Runtime Status
8752**
8753** ^These interfaces are used to retrieve runtime status information
8754** about the performance of SQLite, and optionally to reset various
8755** highwater marks. ^The first argument is an integer code for
8756** the specific parameter to measure. ^(Recognized integer codes
8757** are of the form [status parameters | SQLITE_STATUS_...].)^
8758** ^The current value of the parameter is returned into *pCurrent.
8759** ^The highest recorded value is returned in *pHighwater. ^If the
8760** resetFlag is true, then the highest record value is reset after
8761** *pHighwater is written. ^(Some parameters do not record the highest
8762** value. For those parameters
8763** nothing is written into *pHighwater and the resetFlag is ignored.)^
8764** ^(Other parameters record only the highwater mark and not the current
8765** value. For these latter parameters nothing is written into *pCurrent.)^
8766**
8767** ^The sqlite3_status() and sqlite3_status64() routines return
8768** SQLITE_OK on success and a non-zero [error code] on failure.
8769**
8770** If either the current value or the highwater mark is too large to
8771** be represented by a 32-bit integer, then the values returned by
8772** sqlite3_status() are undefined.
8773**
8774** See also: [sqlite3_db_status()]
8775*/
8776SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
8777SQLITE_API int sqlite3_status64(
8778 int op,
8779 sqlite3_int64 *pCurrent,
8780 sqlite3_int64 *pHighwater,
8781 int resetFlag
8782);
8783
8784
8785/*
8786** CAPI3REF: Status Parameters
8787** KEYWORDS: {status parameters}
8788**
8789** These integer constants designate various run-time status parameters
8790** that can be returned by [sqlite3_status()].
8791**
8792** <dl>
8793** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>
8794** <dd>This parameter is the current amount of memory checked out
8795** using [sqlite3_malloc()], either directly or indirectly. The
8796** figure includes calls made to [sqlite3_malloc()] by the application
8797** and internal memory usage by the SQLite library. Auxiliary page-cache
8798** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
8799** this parameter. The amount returned is the sum of the allocation
8800** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
8801**
8802** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>
8803** <dd>This parameter records the largest memory allocation request
8804** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
8805** internal equivalents). Only the value returned in the
8806** *pHighwater parameter to [sqlite3_status()] is of interest.
8807** The value written into the *pCurrent parameter is undefined.</dd>)^
8808**
8809** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt>
8810** <dd>This parameter records the number of separate memory allocations
8811** currently checked out.</dd>)^
8812**
8813** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
8814** <dd>This parameter returns the number of pages used out of the
8815** [pagecache memory allocator] that was configured using
8816** [SQLITE_CONFIG_PAGECACHE]. The
8817** value returned is in pages, not in bytes.</dd>)^
8818**
8819** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]]
8820** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
8821** <dd>This parameter returns the number of bytes of page cache
8822** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]
8823** buffer and where forced to overflow to [sqlite3_malloc()]. The
8824** returned value includes allocations that overflowed because they
8825** were too large (they were larger than the "sz" parameter to
8826** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
8827** no space was left in the page cache.</dd>)^
8828**
8829** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
8830** <dd>This parameter records the largest memory allocation request
8831** handed to the [pagecache memory allocator]. Only the value returned in the
8832** *pHighwater parameter to [sqlite3_status()] is of interest.
8833** The value written into the *pCurrent parameter is undefined.</dd>)^
8834**
8835** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt>
8836** <dd>No longer used.</dd>
8837**
8838** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
8839** <dd>No longer used.</dd>
8840**
8841** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
8842** <dd>No longer used.</dd>
8843**
8844** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
8845** <dd>The *pHighwater parameter records the deepest parser stack.
8846** The *pCurrent value is undefined. The *pHighwater value is only
8847** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
8848** </dl>
8849**
8850** New status parameters may be added from time to time.
8851*/
8852#define SQLITE_STATUS_MEMORY_USED 0
8853#define SQLITE_STATUS_PAGECACHE_USED 1
8854#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2
8855#define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */
8856#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */
8857#define SQLITE_STATUS_MALLOC_SIZE 5
8858#define SQLITE_STATUS_PARSER_STACK 6
8859#define SQLITE_STATUS_PAGECACHE_SIZE 7
8860#define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */
8861#define SQLITE_STATUS_MALLOC_COUNT 9
8862
8863/*
8864** CAPI3REF: Database Connection Status
8865** METHOD: sqlite3
8866**
8867** ^This interface is used to retrieve runtime status information
8868** about a single [database connection]. ^The first argument is the
8869** database connection object to be interrogated. ^The second argument
8870** is an integer constant, taken from the set of
8871** [SQLITE_DBSTATUS options], that
8872** determines the parameter to interrogate. The set of
8873** [SQLITE_DBSTATUS options] is likely
8874** to grow in future releases of SQLite.
8875**
8876** ^The current value of the requested parameter is written into *pCur
8877** and the highest instantaneous value is written into *pHiwtr. ^If
8878** the resetFlg is true, then the highest instantaneous value is
8879** reset back down to the current value.
8880**
8881** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
8882** non-zero [error code] on failure.
8883**
8884** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
8885*/
8886SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
8887
8888/*
8889** CAPI3REF: Status Parameters for database connections
8890** KEYWORDS: {SQLITE_DBSTATUS options}
8891**
8892** These constants are the available integer "verbs" that can be passed as
8893** the second argument to the [sqlite3_db_status()] interface.
8894**
8895** New verbs may be added in future releases of SQLite. Existing verbs
8896** might be discontinued. Applications should check the return code from
8897** [sqlite3_db_status()] to make sure that the call worked.
8898** The [sqlite3_db_status()] interface will return a non-zero error code
8899** if a discontinued or unsupported verb is invoked.
8900**
8901** <dl>
8902** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
8903** <dd>This parameter returns the number of lookaside memory slots currently
8904** checked out.</dd>)^
8905**
8906** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt>
8907** <dd>This parameter returns the number of malloc attempts that were
8908** satisfied using lookaside memory. Only the high-water value is meaningful;
8909** the current value is always zero.</dd>)^
8910**
8911** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]]
8912** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt>
8913** <dd>This parameter returns the number of malloc attempts that might have
8914** been satisfied using lookaside memory but failed due to the amount of
8915** memory requested being larger than the lookaside slot size.
8916** Only the high-water value is meaningful;
8917** the current value is always zero.</dd>)^
8918**
8919** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]]
8920** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt>
8921** <dd>This parameter returns the number of malloc attempts that might have
8922** been satisfied using lookaside memory but failed due to all lookaside
8923** memory already being in use.
8924** Only the high-water value is meaningful;
8925** the current value is always zero.</dd>)^
8926**
8927** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
8928** <dd>This parameter returns the approximate number of bytes of heap
8929** memory used by all pager caches associated with the database connection.)^
8930** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
8931** </dd>
8932**
8933** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]]
8934** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt>
8935** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a
8936** pager cache is shared between two or more connections the bytes of heap
8937** memory used by that pager cache is divided evenly between the attached
8938** connections.)^ In other words, if none of the pager caches associated
8939** with the database connection are shared, this request returns the same
8940** value as DBSTATUS_CACHE_USED. Or, if one or more of the pager caches are
8941** shared, the value returned by this call will be smaller than that returned
8942** by DBSTATUS_CACHE_USED. ^The highwater mark associated with
8943** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0.</dd>
8944**
8945** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>
8946** <dd>This parameter returns the approximate number of bytes of heap
8947** memory used to store the schema for all databases associated
8948** with the connection - main, temp, and any [ATTACH]-ed databases.)^
8949** ^The full amount of memory used by the schemas is reported, even if the
8950** schema memory is shared with other database connections due to
8951** [shared cache mode] being enabled.
8952** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
8953** </dd>
8954**
8955** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt>
8956** <dd>This parameter returns the approximate number of bytes of heap
8957** and lookaside memory used by all prepared statements associated with
8958** the database connection.)^
8959** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
8960** </dd>
8961**
8962** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt>
8963** <dd>This parameter returns the number of pager cache hits that have
8964** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT
8965** is always 0.
8966** </dd>
8967**
8968** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt>
8969** <dd>This parameter returns the number of pager cache misses that have
8970** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS
8971** is always 0.
8972** </dd>
8973**
8974** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt>
8975** <dd>This parameter returns the number of dirty cache entries that have
8976** been written to disk. Specifically, the number of pages written to the
8977** wal file in wal mode databases, or the number of pages written to the
8978** database file in rollback mode databases. Any pages written as part of
8979** transaction rollback or database recovery operations are not included.
8980** If an IO or other error occurs while writing a page to disk, the effect
8981** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The
8982** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0.
8983** </dd>
8984**
8985** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt>
8986** <dd>This parameter returns the number of dirty cache entries that have
8987** been written to disk in the middle of a transaction due to the page
8988** cache overflowing. Transactions are more efficient if they are written
8989** to disk all at once. When pages spill mid-transaction, that introduces
8990** additional overhead. This parameter can be used to help identify
8991** inefficiencies that can be resolved by increasing the cache size.
8992** </dd>
8993**
8994** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt>
8995** <dd>This parameter returns zero for the current value if and only if
8996** all foreign key constraints (deferred or immediate) have been
8997** resolved.)^ ^The highwater mark is always 0.
8998** </dd>
8999** </dl>
9000*/
9001#define SQLITE_DBSTATUS_LOOKASIDE_USED 0
9002#define SQLITE_DBSTATUS_CACHE_USED 1
9003#define SQLITE_DBSTATUS_SCHEMA_USED 2
9004#define SQLITE_DBSTATUS_STMT_USED 3
9005#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4
9006#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5
9007#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6
9008#define SQLITE_DBSTATUS_CACHE_HIT 7
9009#define SQLITE_DBSTATUS_CACHE_MISS 8
9010#define SQLITE_DBSTATUS_CACHE_WRITE 9
9011#define SQLITE_DBSTATUS_DEFERRED_FKS 10
9012#define SQLITE_DBSTATUS_CACHE_USED_SHARED 11
9013#define SQLITE_DBSTATUS_CACHE_SPILL 12
9014#define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */
9015
9016
9017/*
9018** CAPI3REF: Prepared Statement Status
9019** METHOD: sqlite3_stmt
9020**
9021** ^(Each prepared statement maintains various
9022** [SQLITE_STMTSTATUS counters] that measure the number
9023** of times it has performed specific operations.)^ These counters can
9024** be used to monitor the performance characteristics of the prepared
9025** statements. For example, if the number of table steps greatly exceeds
9026** the number of table searches or result rows, that would tend to indicate
9027** that the prepared statement is using a full table scan rather than
9028** an index.
9029**
9030** ^(This interface is used to retrieve and reset counter values from
9031** a [prepared statement]. The first argument is the prepared statement
9032** object to be interrogated. The second argument
9033** is an integer code for a specific [SQLITE_STMTSTATUS counter]
9034** to be interrogated.)^
9035** ^The current value of the requested counter is returned.
9036** ^If the resetFlg is true, then the counter is reset to zero after this
9037** interface call returns.
9038**
9039** See also: [sqlite3_status()] and [sqlite3_db_status()].
9040*/
9041SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
9042
9043/*
9044** CAPI3REF: Status Parameters for prepared statements
9045** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters}
9046**
9047** These preprocessor macros define integer codes that name counter
9048** values associated with the [sqlite3_stmt_status()] interface.
9049** The meanings of the various counters are as follows:
9050**
9051** <dl>
9052** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
9053** <dd>^This is the number of times that SQLite has stepped forward in
9054** a table as part of a full table scan. Large numbers for this counter
9055** may indicate opportunities for performance improvement through
9056** careful use of indices.</dd>
9057**
9058** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt>
9059** <dd>^This is the number of sort operations that have occurred.
9060** A non-zero value in this counter may indicate an opportunity to
9061** improvement performance through careful use of indices.</dd>
9062**
9063** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt>
9064** <dd>^This is the number of rows inserted into transient indices that
9065** were created automatically in order to help joins run faster.
9066** A non-zero value in this counter may indicate an opportunity to
9067** improvement performance by adding permanent indices that do not
9068** need to be reinitialized each time the statement is run.</dd>
9069**
9070** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt>
9071** <dd>^This is the number of virtual machine operations executed
9072** by the prepared statement if that number is less than or equal
9073** to 2147483647. The number of virtual machine operations can be
9074** used as a proxy for the total work done by the prepared statement.
9075** If the number of virtual machine operations exceeds 2147483647
9076** then the value returned by this statement status code is undefined.
9077**
9078** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt>
9079** <dd>^This is the number of times that the prepare statement has been
9080** automatically regenerated due to schema changes or changes to
9081** [bound parameters] that might affect the query plan.
9082**
9083** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt>
9084** <dd>^This is the number of times that the prepared statement has
9085** been run. A single "run" for the purposes of this counter is one
9086** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()].
9087** The counter is incremented on the first [sqlite3_step()] call of each
9088** cycle.
9089**
9090** [[SQLITE_STMTSTATUS_FILTER_MISS]]
9091** [[SQLITE_STMTSTATUS_FILTER HIT]]
9092** <dt>SQLITE_STMTSTATUS_FILTER_HIT<br>
9093** SQLITE_STMTSTATUS_FILTER_MISS</dt>
9094** <dd>^SQLITE_STMTSTATUS_FILTER_HIT is the number of times that a join
9095** step was bypassed because a Bloom filter returned not-found. The
9096** corresponding SQLITE_STMTSTATUS_FILTER_MISS value is the number of
9097** times that the Bloom filter returned a find, and thus the join step
9098** had to be processed as normal.
9099**
9100** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt>
9101** <dd>^This is the approximate number of bytes of heap memory
9102** used to store the prepared statement. ^This value is not actually
9103** a counter, and so the resetFlg parameter to sqlite3_stmt_status()
9104** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED.
9105** </dd>
9106** </dl>
9107*/
9108#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1
9109#define SQLITE_STMTSTATUS_SORT 2
9110#define SQLITE_STMTSTATUS_AUTOINDEX 3
9111#define SQLITE_STMTSTATUS_VM_STEP 4
9112#define SQLITE_STMTSTATUS_REPREPARE 5
9113#define SQLITE_STMTSTATUS_RUN 6
9114#define SQLITE_STMTSTATUS_FILTER_MISS 7
9115#define SQLITE_STMTSTATUS_FILTER_HIT 8
9116#define SQLITE_STMTSTATUS_MEMUSED 99
9117
9118/*
9119** CAPI3REF: Custom Page Cache Object
9120**
9121** The sqlite3_pcache type is opaque. It is implemented by
9122** the pluggable module. The SQLite core has no knowledge of
9123** its size or internal structure and never deals with the
9124** sqlite3_pcache object except by holding and passing pointers
9125** to the object.
9126**
9127** See [sqlite3_pcache_methods2] for additional information.
9128*/
9129typedef struct sqlite3_pcache sqlite3_pcache;
9130
9131/*
9132** CAPI3REF: Custom Page Cache Object
9133**
9134** The sqlite3_pcache_page object represents a single page in the
9135** page cache. The page cache will allocate instances of this
9136** object. Various methods of the page cache use pointers to instances
9137** of this object as parameters or as their return value.
9138**
9139** See [sqlite3_pcache_methods2] for additional information.
9140*/
9141typedef struct sqlite3_pcache_page sqlite3_pcache_page;
9142struct sqlite3_pcache_page {
9143 void *pBuf; /* The content of the page */
9144 void *pExtra; /* Extra information associated with the page */
9145};
9146
9147/*
9148** CAPI3REF: Application Defined Page Cache.
9149** KEYWORDS: {page cache}
9150**
9151** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can
9152** register an alternative page cache implementation by passing in an
9153** instance of the sqlite3_pcache_methods2 structure.)^
9154** In many applications, most of the heap memory allocated by
9155** SQLite is used for the page cache.
9156** By implementing a
9157** custom page cache using this API, an application can better control
9158** the amount of memory consumed by SQLite, the way in which
9159** that memory is allocated and released, and the policies used to
9160** determine exactly which parts of a database file are cached and for
9161** how long.
9162**
9163** The alternative page cache mechanism is an
9164** extreme measure that is only needed by the most demanding applications.
9165** The built-in page cache is recommended for most uses.
9166**
9167** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an
9168** internal buffer by SQLite within the call to [sqlite3_config]. Hence
9169** the application may discard the parameter after the call to
9170** [sqlite3_config()] returns.)^
9171**
9172** [[the xInit() page cache method]]
9173** ^(The xInit() method is called once for each effective
9174** call to [sqlite3_initialize()])^
9175** (usually only once during the lifetime of the process). ^(The xInit()
9176** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^
9177** The intent of the xInit() method is to set up global data structures
9178** required by the custom page cache implementation.
9179** ^(If the xInit() method is NULL, then the
9180** built-in default page cache is used instead of the application defined
9181** page cache.)^
9182**
9183** [[the xShutdown() page cache method]]
9184** ^The xShutdown() method is called by [sqlite3_shutdown()].
9185** It can be used to clean up
9186** any outstanding resources before process shutdown, if required.
9187** ^The xShutdown() method may be NULL.
9188**
9189** ^SQLite automatically serializes calls to the xInit method,
9190** so the xInit method need not be threadsafe. ^The
9191** xShutdown method is only called from [sqlite3_shutdown()] so it does
9192** not need to be threadsafe either. All other methods must be threadsafe
9193** in multithreaded applications.
9194**
9195** ^SQLite will never invoke xInit() more than once without an intervening
9196** call to xShutdown().
9197**
9198** [[the xCreate() page cache methods]]
9199** ^SQLite invokes the xCreate() method to construct a new cache instance.
9200** SQLite will typically create one cache instance for each open database file,
9201** though this is not guaranteed. ^The
9202** first parameter, szPage, is the size in bytes of the pages that must
9203** be allocated by the cache. ^szPage will always a power of two. ^The
9204** second parameter szExtra is a number of bytes of extra storage
9205** associated with each page cache entry. ^The szExtra parameter will
9206** a number less than 250. SQLite will use the
9207** extra szExtra bytes on each page to store metadata about the underlying
9208** database page on disk. The value passed into szExtra depends
9209** on the SQLite version, the target platform, and how SQLite was compiled.
9210** ^The third argument to xCreate(), bPurgeable, is true if the cache being
9211** created will be used to cache database pages of a file stored on disk, or
9212** false if it is used for an in-memory database. The cache implementation
9213** does not have to do anything special based with the value of bPurgeable;
9214** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will
9215** never invoke xUnpin() except to deliberately delete a page.
9216** ^In other words, calls to xUnpin() on a cache with bPurgeable set to
9217** false will always have the "discard" flag set to true.
9218** ^Hence, a cache created with bPurgeable false will
9219** never contain any unpinned pages.
9220**
9221** [[the xCachesize() page cache method]]
9222** ^(The xCachesize() method may be called at any time by SQLite to set the
9223** suggested maximum cache-size (number of pages stored by) the cache
9224** instance passed as the first argument. This is the value configured using
9225** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable
9226** parameter, the implementation is not required to do anything with this
9227** value; it is advisory only.
9228**
9229** [[the xPagecount() page cache methods]]
9230** The xPagecount() method must return the number of pages currently
9231** stored in the cache, both pinned and unpinned.
9232**
9233** [[the xFetch() page cache methods]]
9234** The xFetch() method locates a page in the cache and returns a pointer to
9235** an sqlite3_pcache_page object associated with that page, or a NULL pointer.
9236** The pBuf element of the returned sqlite3_pcache_page object will be a
9237** pointer to a buffer of szPage bytes used to store the content of a
9238** single database page. The pExtra element of sqlite3_pcache_page will be
9239** a pointer to the szExtra bytes of extra storage that SQLite has requested
9240** for each entry in the page cache.
9241**
9242** The page to be fetched is determined by the key. ^The minimum key value
9243** is 1. After it has been retrieved using xFetch, the page is considered
9244** to be "pinned".
9245**
9246** If the requested page is already in the page cache, then the page cache
9247** implementation must return a pointer to the page buffer with its content
9248** intact. If the requested page is not already in the cache, then the
9249** cache implementation should use the value of the createFlag
9250** parameter to help it determined what action to take:
9251**
9252** <table border=1 width=85% align=center>
9253** <tr><th> createFlag <th> Behavior when page is not already in cache
9254** <tr><td> 0 <td> Do not allocate a new page. Return NULL.
9255** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so.
9256** Otherwise return NULL.
9257** <tr><td> 2 <td> Make every effort to allocate a new page. Only return
9258** NULL if allocating a new page is effectively impossible.
9259** </table>
9260**
9261** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite
9262** will only use a createFlag of 2 after a prior call with a createFlag of 1
9263** failed.)^ In between the xFetch() calls, SQLite may
9264** attempt to unpin one or more cache pages by spilling the content of
9265** pinned pages to disk and synching the operating system disk cache.
9266**
9267** [[the xUnpin() page cache method]]
9268** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
9269** as its second argument. If the third parameter, discard, is non-zero,
9270** then the page must be evicted from the cache.
9271** ^If the discard parameter is
9272** zero, then the page may be discarded or retained at the discretion of
9273** page cache implementation. ^The page cache implementation
9274** may choose to evict unpinned pages at any time.
9275**
9276** The cache must not perform any reference counting. A single
9277** call to xUnpin() unpins the page regardless of the number of prior calls
9278** to xFetch().
9279**
9280** [[the xRekey() page cache methods]]
9281** The xRekey() method is used to change the key value associated with the
9282** page passed as the second argument. If the cache
9283** previously contains an entry associated with newKey, it must be
9284** discarded. ^Any prior cache entry associated with newKey is guaranteed not
9285** to be pinned.
9286**
9287** When SQLite calls the xTruncate() method, the cache must discard all
9288** existing cache entries with page numbers (keys) greater than or equal
9289** to the value of the iLimit parameter passed to xTruncate(). If any
9290** of these pages are pinned, they are implicitly unpinned, meaning that
9291** they can be safely discarded.
9292**
9293** [[the xDestroy() page cache method]]
9294** ^The xDestroy() method is used to delete a cache allocated by xCreate().
9295** All resources associated with the specified cache should be freed. ^After
9296** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
9297** handle invalid, and will not use it with any other sqlite3_pcache_methods2
9298** functions.
9299**
9300** [[the xShrink() page cache method]]
9301** ^SQLite invokes the xShrink() method when it wants the page cache to
9302** free up as much of heap memory as possible. The page cache implementation
9303** is not obligated to free any memory, but well-behaved implementations should
9304** do their best.
9305*/
9306typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2;
9307struct sqlite3_pcache_methods2 {
9308 int iVersion;
9309 void *pArg;
9310 int (*xInit)(void*);
9311 void (*xShutdown)(void*);
9312 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable);
9313 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
9314 int (*xPagecount)(sqlite3_pcache*);
9315 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
9316 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard);
9317 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*,
9318 unsigned oldKey, unsigned newKey);
9319 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
9320 void (*xDestroy)(sqlite3_pcache*);
9321 void (*xShrink)(sqlite3_pcache*);
9322};
9323
9324/*
9325** This is the obsolete pcache_methods object that has now been replaced
9326** by sqlite3_pcache_methods2. This object is not used by SQLite. It is
9327** retained in the header file for backwards compatibility only.
9328*/
9329typedef struct sqlite3_pcache_methods sqlite3_pcache_methods;
9330struct sqlite3_pcache_methods {
9331 void *pArg;
9332 int (*xInit)(void*);
9333 void (*xShutdown)(void*);
9334 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable);
9335 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
9336 int (*xPagecount)(sqlite3_pcache*);
9337 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
9338 void (*xUnpin)(sqlite3_pcache*, void*, int discard);
9339 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey);
9340 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
9341 void (*xDestroy)(sqlite3_pcache*);
9342};
9343
9344
9345/*
9346** CAPI3REF: Online Backup Object
9347**
9348** The sqlite3_backup object records state information about an ongoing
9349** online backup operation. ^The sqlite3_backup object is created by
9350** a call to [sqlite3_backup_init()] and is destroyed by a call to
9351** [sqlite3_backup_finish()].
9352**
9353** See Also: [Using the SQLite Online Backup API]
9354*/
9355typedef struct sqlite3_backup sqlite3_backup;
9356
9357/*
9358** CAPI3REF: Online Backup API.
9359**
9360** The backup API copies the content of one database into another.
9361** It is useful either for creating backups of databases or
9362** for copying in-memory databases to or from persistent files.
9363**
9364** See Also: [Using the SQLite Online Backup API]
9365**
9366** ^SQLite holds a write transaction open on the destination database file
9367** for the duration of the backup operation.
9368** ^The source database is read-locked only while it is being read;
9369** it is not locked continuously for the entire backup operation.
9370** ^Thus, the backup may be performed on a live source database without
9371** preventing other database connections from
9372** reading or writing to the source database while the backup is underway.
9373**
9374** ^(To perform a backup operation:
9375** <ol>
9376** <li><b>sqlite3_backup_init()</b> is called once to initialize the
9377** backup,
9378** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer
9379** the data between the two databases, and finally
9380** <li><b>sqlite3_backup_finish()</b> is called to release all resources
9381** associated with the backup operation.
9382** </ol>)^
9383** There should be exactly one call to sqlite3_backup_finish() for each
9384** successful call to sqlite3_backup_init().
9385**
9386** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b>
9387**
9388** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the
9389** [database connection] associated with the destination database
9390** and the database name, respectively.
9391** ^The database name is "main" for the main database, "temp" for the
9392** temporary database, or the name specified after the AS keyword in
9393** an [ATTACH] statement for an attached database.
9394** ^The S and M arguments passed to
9395** sqlite3_backup_init(D,N,S,M) identify the [database connection]
9396** and database name of the source database, respectively.
9397** ^The source and destination [database connections] (parameters S and D)
9398** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
9399** an error.
9400**
9401** ^A call to sqlite3_backup_init() will fail, returning NULL, if
9402** there is already a read or read-write transaction open on the
9403** destination database.
9404**
9405** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
9406** returned and an error code and error message are stored in the
9407** destination [database connection] D.
9408** ^The error code and message for the failed call to sqlite3_backup_init()
9409** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
9410** [sqlite3_errmsg16()] functions.
9411** ^A successful call to sqlite3_backup_init() returns a pointer to an
9412** [sqlite3_backup] object.
9413** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
9414** sqlite3_backup_finish() functions to perform the specified backup
9415** operation.
9416**
9417** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b>
9418**
9419** ^Function sqlite3_backup_step(B,N) will copy up to N pages between
9420** the source and destination databases specified by [sqlite3_backup] object B.
9421** ^If N is negative, all remaining source pages are copied.
9422** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
9423** are still more pages to be copied, then the function returns [SQLITE_OK].
9424** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
9425** from source to destination, then it returns [SQLITE_DONE].
9426** ^If an error occurs while running sqlite3_backup_step(B,N),
9427** then an [error code] is returned. ^As well as [SQLITE_OK] and
9428** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
9429** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
9430** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
9431**
9432** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if
9433** <ol>
9434** <li> the destination database was opened read-only, or
9435** <li> the destination database is using write-ahead-log journaling
9436** and the destination and source page sizes differ, or
9437** <li> the destination database is an in-memory database and the
9438** destination and source page sizes differ.
9439** </ol>)^
9440**
9441** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
9442** the [sqlite3_busy_handler | busy-handler function]
9443** is invoked (if one is specified). ^If the
9444** busy-handler returns non-zero before the lock is available, then
9445** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
9446** sqlite3_backup_step() can be retried later. ^If the source
9447** [database connection]
9448** is being used to write to the source database when sqlite3_backup_step()
9449** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
9450** case the call to sqlite3_backup_step() can be retried later on. ^(If
9451** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or
9452** [SQLITE_READONLY] is returned, then
9453** there is no point in retrying the call to sqlite3_backup_step(). These
9454** errors are considered fatal.)^ The application must accept
9455** that the backup operation has failed and pass the backup operation handle
9456** to the sqlite3_backup_finish() to release associated resources.
9457**
9458** ^The first call to sqlite3_backup_step() obtains an exclusive lock
9459** on the destination file. ^The exclusive lock is not released until either
9460** sqlite3_backup_finish() is called or the backup operation is complete
9461** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to
9462** sqlite3_backup_step() obtains a [shared lock] on the source database that
9463** lasts for the duration of the sqlite3_backup_step() call.
9464** ^Because the source database is not locked between calls to
9465** sqlite3_backup_step(), the source database may be modified mid-way
9466** through the backup process. ^If the source database is modified by an
9467** external process or via a database connection other than the one being
9468** used by the backup operation, then the backup will be automatically
9469** restarted by the next call to sqlite3_backup_step(). ^If the source
9470** database is modified by using the same database connection as is used
9471** by the backup operation, then the backup database is automatically
9472** updated at the same time.
9473**
9474** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b>
9475**
9476** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the
9477** application wishes to abandon the backup operation, the application
9478** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
9479** ^The sqlite3_backup_finish() interfaces releases all
9480** resources associated with the [sqlite3_backup] object.
9481** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
9482** active write-transaction on the destination database is rolled back.
9483** The [sqlite3_backup] object is invalid
9484** and may not be used following a call to sqlite3_backup_finish().
9485**
9486** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
9487** sqlite3_backup_step() errors occurred, regardless of whether or not
9488** sqlite3_backup_step() completed.
9489** ^If an out-of-memory condition or IO error occurred during any prior
9490** sqlite3_backup_step() call on the same [sqlite3_backup] object, then
9491** sqlite3_backup_finish() returns the corresponding [error code].
9492**
9493** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
9494** is not a permanent error and does not affect the return value of
9495** sqlite3_backup_finish().
9496**
9497** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]]
9498** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>
9499**
9500** ^The sqlite3_backup_remaining() routine returns the number of pages still
9501** to be backed up at the conclusion of the most recent sqlite3_backup_step().
9502** ^The sqlite3_backup_pagecount() routine returns the total number of pages
9503** in the source database at the conclusion of the most recent
9504** sqlite3_backup_step().
9505** ^(The values returned by these functions are only updated by
9506** sqlite3_backup_step(). If the source database is modified in a way that
9507** changes the size of the source database or the number of pages remaining,
9508** those changes are not reflected in the output of sqlite3_backup_pagecount()
9509** and sqlite3_backup_remaining() until after the next
9510** sqlite3_backup_step().)^
9511**
9512** <b>Concurrent Usage of Database Handles</b>
9513**
9514** ^The source [database connection] may be used by the application for other
9515** purposes while a backup operation is underway or being initialized.
9516** ^If SQLite is compiled and configured to support threadsafe database
9517** connections, then the source database connection may be used concurrently
9518** from within other threads.
9519**
9520** However, the application must guarantee that the destination
9521** [database connection] is not passed to any other API (by any thread) after
9522** sqlite3_backup_init() is called and before the corresponding call to
9523** sqlite3_backup_finish(). SQLite does not currently check to see
9524** if the application incorrectly accesses the destination [database connection]
9525** and so no error code is reported, but the operations may malfunction
9526** nevertheless. Use of the destination database connection while a
9527** backup is in progress might also cause a mutex deadlock.
9528**
9529** If running in [shared cache mode], the application must
9530** guarantee that the shared cache used by the destination database
9531** is not accessed while the backup is running. In practice this means
9532** that the application must guarantee that the disk file being
9533** backed up to is not accessed by any connection within the process,
9534** not just the specific connection that was passed to sqlite3_backup_init().
9535**
9536** The [sqlite3_backup] object itself is partially threadsafe. Multiple
9537** threads may safely make multiple concurrent calls to sqlite3_backup_step().
9538** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
9539** APIs are not strictly speaking threadsafe. If they are invoked at the
9540** same time as another thread is invoking sqlite3_backup_step() it is
9541** possible that they return invalid values.
9542**
9543** <b>Alternatives To Using The Backup API</b>
9544**
9545** Other techniques for safely creating a consistent backup of an SQLite
9546** database include:
9547**
9548** <ul>
9549** <li> The [VACUUM INTO] command.
9550** <li> The [sqlite3_rsync] utility program.
9551** </ul>
9552*/
9553SQLITE_API sqlite3_backup *sqlite3_backup_init(
9554 sqlite3 *pDest, /* Destination database handle */
9555 const char *zDestName, /* Destination database name */
9556 sqlite3 *pSource, /* Source database handle */
9557 const char *zSourceName /* Source database name */
9558);
9559SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage);
9560SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p);
9561SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p);
9562SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p);
9563
9564/*
9565** CAPI3REF: Unlock Notification
9566** METHOD: sqlite3
9567**
9568** ^When running in shared-cache mode, a database operation may fail with
9569** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
9570** individual tables within the shared-cache cannot be obtained. See
9571** [SQLite Shared-Cache Mode] for a description of shared-cache locking.
9572** ^This API may be used to register a callback that SQLite will invoke
9573** when the connection currently holding the required lock relinquishes it.
9574** ^This API is only available if the library was compiled with the
9575** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
9576**
9577** See Also: [Using the SQLite Unlock Notification Feature].
9578**
9579** ^Shared-cache locks are released when a database connection concludes
9580** its current transaction, either by committing it or rolling it back.
9581**
9582** ^When a connection (known as the blocked connection) fails to obtain a
9583** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
9584** identity of the database connection (the blocking connection) that
9585** has locked the required resource is stored internally. ^After an
9586** application receives an SQLITE_LOCKED error, it may call the
9587** sqlite3_unlock_notify() method with the blocked connection handle as
9588** the first argument to register for a callback that will be invoked
9589** when the blocking connections current transaction is concluded. ^The
9590** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
9591** call that concludes the blocking connection's transaction.
9592**
9593** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
9594** there is a chance that the blocking connection will have already
9595** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
9596** If this happens, then the specified callback is invoked immediately,
9597** from within the call to sqlite3_unlock_notify().)^
9598**
9599** ^If the blocked connection is attempting to obtain a write-lock on a
9600** shared-cache table, and more than one other connection currently holds
9601** a read-lock on the same table, then SQLite arbitrarily selects one of
9602** the other connections to use as the blocking connection.
9603**
9604** ^(There may be at most one unlock-notify callback registered by a
9605** blocked connection. If sqlite3_unlock_notify() is called when the
9606** blocked connection already has a registered unlock-notify callback,
9607** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
9608** called with a NULL pointer as its second argument, then any existing
9609** unlock-notify callback is canceled. ^The blocked connections
9610** unlock-notify callback may also be canceled by closing the blocked
9611** connection using [sqlite3_close()].
9612**
9613** The unlock-notify callback is not reentrant. If an application invokes
9614** any sqlite3_xxx API functions from within an unlock-notify callback, a
9615** crash or deadlock may be the result.
9616**
9617** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
9618** returns SQLITE_OK.
9619**
9620** <b>Callback Invocation Details</b>
9621**
9622** When an unlock-notify callback is registered, the application provides a
9623** single void* pointer that is passed to the callback when it is invoked.
9624** However, the signature of the callback function allows SQLite to pass
9625** it an array of void* context pointers. The first argument passed to
9626** an unlock-notify callback is a pointer to an array of void* pointers,
9627** and the second is the number of entries in the array.
9628**
9629** When a blocking connection's transaction is concluded, there may be
9630** more than one blocked connection that has registered for an unlock-notify
9631** callback. ^If two or more such blocked connections have specified the
9632** same callback function, then instead of invoking the callback function
9633** multiple times, it is invoked once with the set of void* context pointers
9634** specified by the blocked connections bundled together into an array.
9635** This gives the application an opportunity to prioritize any actions
9636** related to the set of unblocked database connections.
9637**
9638** <b>Deadlock Detection</b>
9639**
9640** Assuming that after registering for an unlock-notify callback a
9641** database waits for the callback to be issued before taking any further
9642** action (a reasonable assumption), then using this API may cause the
9643** application to deadlock. For example, if connection X is waiting for
9644** connection Y's transaction to be concluded, and similarly connection
9645** Y is waiting on connection X's transaction, then neither connection
9646** will proceed and the system may remain deadlocked indefinitely.
9647**
9648** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
9649** detection. ^If a given call to sqlite3_unlock_notify() would put the
9650** system in a deadlocked state, then SQLITE_LOCKED is returned and no
9651** unlock-notify callback is registered. The system is said to be in
9652** a deadlocked state if connection A has registered for an unlock-notify
9653** callback on the conclusion of connection B's transaction, and connection
9654** B has itself registered for an unlock-notify callback when connection
9655** A's transaction is concluded. ^Indirect deadlock is also detected, so
9656** the system is also considered to be deadlocked if connection B has
9657** registered for an unlock-notify callback on the conclusion of connection
9658** C's transaction, where connection C is waiting on connection A. ^Any
9659** number of levels of indirection are allowed.
9660**
9661** <b>The "DROP TABLE" Exception</b>
9662**
9663** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost
9664** always appropriate to call sqlite3_unlock_notify(). There is however,
9665** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
9666** SQLite checks if there are any currently executing SELECT statements
9667** that belong to the same connection. If there are, SQLITE_LOCKED is
9668** returned. In this case there is no "blocking connection", so invoking
9669** sqlite3_unlock_notify() results in the unlock-notify callback being
9670** invoked immediately. If the application then re-attempts the "DROP TABLE"
9671** or "DROP INDEX" query, an infinite loop might be the result.
9672**
9673** One way around this problem is to check the extended error code returned
9674** by an sqlite3_step() call. ^(If there is a blocking connection, then the
9675** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
9676** the special "DROP TABLE/INDEX" case, the extended error code is just
9677** SQLITE_LOCKED.)^
9678*/
9679SQLITE_API int sqlite3_unlock_notify(
9680 sqlite3 *pBlocked, /* Waiting connection */
9681 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */
9682 void *pNotifyArg /* Argument to pass to xNotify */
9683);
9684
9685
9686/*
9687** CAPI3REF: String Comparison
9688**
9689** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications
9690** and extensions to compare the contents of two buffers containing UTF-8
9691** strings in a case-independent fashion, using the same definition of "case
9692** independence" that SQLite uses internally when comparing identifiers.
9693*/
9694SQLITE_API int sqlite3_stricmp(const char *, const char *);
9695SQLITE_API int sqlite3_strnicmp(const char *, const char *, int);
9696
9697/*
9698** CAPI3REF: String Globbing
9699*
9700** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if
9701** string X matches the [GLOB] pattern P.
9702** ^The definition of [GLOB] pattern matching used in
9703** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the
9704** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function
9705** is case sensitive.
9706**
9707** Note that this routine returns zero on a match and non-zero if the strings
9708** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
9709**
9710** See also: [sqlite3_strlike()].
9711*/
9712SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr);
9713
9714/*
9715** CAPI3REF: String LIKE Matching
9716*
9717** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if
9718** string X matches the [LIKE] pattern P with escape character E.
9719** ^The definition of [LIKE] pattern matching used in
9720** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E"
9721** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without
9722** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0.
9723** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case
9724** insensitive - equivalent upper and lower case ASCII characters match
9725** one another.
9726**
9727** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though
9728** only ASCII characters are case folded.
9729**
9730** Note that this routine returns zero on a match and non-zero if the strings
9731** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
9732**
9733** See also: [sqlite3_strglob()].
9734*/
9735SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc);
9736
9737/*
9738** CAPI3REF: Error Logging Interface
9739**
9740** ^The [sqlite3_log()] interface writes a message into the [error log]
9741** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
9742** ^If logging is enabled, the zFormat string and subsequent arguments are
9743** used with [sqlite3_snprintf()] to generate the final output string.
9744**
9745** The sqlite3_log() interface is intended for use by extensions such as
9746** virtual tables, collating functions, and SQL functions. While there is
9747** nothing to prevent an application from calling sqlite3_log(), doing so
9748** is considered bad form.
9749**
9750** The zFormat string must not be NULL.
9751**
9752** To avoid deadlocks and other threading problems, the sqlite3_log() routine
9753** will not use dynamically allocated memory. The log message is stored in
9754** a fixed-length buffer on the stack. If the log message is longer than
9755** a few hundred characters, it will be truncated to the length of the
9756** buffer.
9757*/
9758SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...);
9759
9760/*
9761** CAPI3REF: Write-Ahead Log Commit Hook
9762** METHOD: sqlite3
9763**
9764** ^The [sqlite3_wal_hook()] function is used to register a callback that
9765** is invoked each time data is committed to a database in wal mode.
9766**
9767** ^(The callback is invoked by SQLite after the commit has taken place and
9768** the associated write-lock on the database released)^, so the implementation
9769** may read, write or [checkpoint] the database as required.
9770**
9771** ^The first parameter passed to the callback function when it is invoked
9772** is a copy of the third parameter passed to sqlite3_wal_hook() when
9773** registering the callback. ^The second is a copy of the database handle.
9774** ^The third parameter is the name of the database that was written to -
9775** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter
9776** is the number of pages currently in the write-ahead log file,
9777** including those that were just committed.
9778**
9779** The callback function should normally return [SQLITE_OK]. ^If an error
9780** code is returned, that error will propagate back up through the
9781** SQLite code base to cause the statement that provoked the callback
9782** to report an error, though the commit will have still occurred. If the
9783** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value
9784** that does not correspond to any valid SQLite error code, the results
9785** are undefined.
9786**
9787** A single database handle may have at most a single write-ahead log callback
9788** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any
9789** previously registered write-ahead log callback. ^The return value is
9790** a copy of the third parameter from the previous call, if any, or 0.
9791** ^Note that the [sqlite3_wal_autocheckpoint()] interface and the
9792** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will
9793** overwrite any prior [sqlite3_wal_hook()] settings.
9794*/
9795SQLITE_API void *sqlite3_wal_hook(
9796 sqlite3*,
9797 int(*)(void *,sqlite3*,const char*,int),
9798 void*
9799);
9800
9801/*
9802** CAPI3REF: Configure an auto-checkpoint
9803** METHOD: sqlite3
9804**
9805** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
9806** [sqlite3_wal_hook()] that causes any database on [database connection] D
9807** to automatically [checkpoint]
9808** after committing a transaction if there are N or
9809** more frames in the [write-ahead log] file. ^Passing zero or
9810** a negative value as the nFrame parameter disables automatic
9811** checkpoints entirely.
9812**
9813** ^The callback registered by this function replaces any existing callback
9814** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback
9815** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism
9816** configured by this function.
9817**
9818** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
9819** from SQL.
9820**
9821** ^Checkpoints initiated by this mechanism are
9822** [sqlite3_wal_checkpoint_v2|PASSIVE].
9823**
9824** ^Every new [database connection] defaults to having the auto-checkpoint
9825** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
9826** pages. The use of this interface
9827** is only necessary if the default setting is found to be suboptimal
9828** for a particular application.
9829*/
9830SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N);
9831
9832/*
9833** CAPI3REF: Checkpoint a database
9834** METHOD: sqlite3
9835**
9836** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to
9837** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^
9838**
9839** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the
9840** [write-ahead log] for database X on [database connection] D to be
9841** transferred into the database file and for the write-ahead log to
9842** be reset. See the [checkpointing] documentation for addition
9843** information.
9844**
9845** This interface used to be the only way to cause a checkpoint to
9846** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()]
9847** interface was added. This interface is retained for backwards
9848** compatibility and as a convenience for applications that need to manually
9849** start a callback but which do not need the full power (and corresponding
9850** complication) of [sqlite3_wal_checkpoint_v2()].
9851*/
9852SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);
9853
9854/*
9855** CAPI3REF: Checkpoint a database
9856** METHOD: sqlite3
9857**
9858** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint
9859** operation on database X of [database connection] D in mode M. Status
9860** information is written back into integers pointed to by L and C.)^
9861** ^(The M parameter must be a valid [checkpoint mode]:)^
9862**
9863** <dl>
9864** <dt>SQLITE_CHECKPOINT_PASSIVE<dd>
9865** ^Checkpoint as many frames as possible without waiting for any database
9866** readers or writers to finish, then sync the database file if all frames
9867** in the log were checkpointed. ^The [busy-handler callback]
9868** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode.
9869** ^On the other hand, passive mode might leave the checkpoint unfinished
9870** if there are concurrent readers or writers.
9871**
9872** <dt>SQLITE_CHECKPOINT_FULL<dd>
9873** ^This mode blocks (it invokes the
9874** [sqlite3_busy_handler|busy-handler callback]) until there is no
9875** database writer and all readers are reading from the most recent database
9876** snapshot. ^It then checkpoints all frames in the log file and syncs the
9877** database file. ^This mode blocks new database writers while it is pending,
9878** but new database readers are allowed to continue unimpeded.
9879**
9880** <dt>SQLITE_CHECKPOINT_RESTART<dd>
9881** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition
9882** that after checkpointing the log file it blocks (calls the
9883** [busy-handler callback])
9884** until all readers are reading from the database file only. ^This ensures
9885** that the next writer will restart the log file from the beginning.
9886** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new
9887** database writer attempts while it is pending, but does not impede readers.
9888**
9889** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd>
9890** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the
9891** addition that it also truncates the log file to zero bytes just prior
9892** to a successful return.
9893** </dl>
9894**
9895** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in
9896** the log file or to -1 if the checkpoint could not run because
9897** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not
9898** NULL,then *pnCkpt is set to the total number of checkpointed frames in the
9899** log file (including any that were already checkpointed before the function
9900** was called) or to -1 if the checkpoint could not run due to an error or
9901** because the database is not in WAL mode. ^Note that upon successful
9902** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been
9903** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero.
9904**
9905** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If
9906** any other process is running a checkpoint operation at the same time, the
9907** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a
9908** busy-handler configured, it will not be invoked in this case.
9909**
9910** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the
9911** exclusive "writer" lock on the database file. ^If the writer lock cannot be
9912** obtained immediately, and a busy-handler is configured, it is invoked and
9913** the writer lock retried until either the busy-handler returns 0 or the lock
9914** is successfully obtained. ^The busy-handler is also invoked while waiting for
9915** database readers as described above. ^If the busy-handler returns 0 before
9916** the writer lock is obtained or while waiting for database readers, the
9917** checkpoint operation proceeds from that point in the same way as
9918** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible
9919** without blocking any further. ^SQLITE_BUSY is returned in this case.
9920**
9921** ^If parameter zDb is NULL or points to a zero length string, then the
9922** specified operation is attempted on all WAL databases [attached] to
9923** [database connection] db. In this case the
9924** values written to output parameters *pnLog and *pnCkpt are undefined. ^If
9925** an SQLITE_BUSY error is encountered when processing one or more of the
9926** attached WAL databases, the operation is still attempted on any remaining
9927** attached databases and SQLITE_BUSY is returned at the end. ^If any other
9928** error occurs while processing an attached database, processing is abandoned
9929** and the error code is returned to the caller immediately. ^If no error
9930** (SQLITE_BUSY or otherwise) is encountered while processing the attached
9931** databases, SQLITE_OK is returned.
9932**
9933** ^If database zDb is the name of an attached database that is not in WAL
9934** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If
9935** zDb is not NULL (or a zero length string) and is not the name of any
9936** attached database, SQLITE_ERROR is returned to the caller.
9937**
9938** ^Unless it returns SQLITE_MISUSE,
9939** the sqlite3_wal_checkpoint_v2() interface
9940** sets the error information that is queried by
9941** [sqlite3_errcode()] and [sqlite3_errmsg()].
9942**
9943** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface
9944** from SQL.
9945*/
9946SQLITE_API int sqlite3_wal_checkpoint_v2(
9947 sqlite3 *db, /* Database handle */
9948 const char *zDb, /* Name of attached database (or NULL) */
9949 int eMode, /* SQLITE_CHECKPOINT_* value */
9950 int *pnLog, /* OUT: Size of WAL log in frames */
9951 int *pnCkpt /* OUT: Total number of frames checkpointed */
9952);
9953
9954/*
9955** CAPI3REF: Checkpoint Mode Values
9956** KEYWORDS: {checkpoint mode}
9957**
9958** These constants define all valid values for the "checkpoint mode" passed
9959** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface.
9960** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the
9961** meaning of each of these checkpoint modes.
9962*/
9963#define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */
9964#define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */
9965#define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for readers */
9966#define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */
9967
9968/*
9969** CAPI3REF: Virtual Table Interface Configuration
9970**
9971** This function may be called by either the [xConnect] or [xCreate] method
9972** of a [virtual table] implementation to configure
9973** various facets of the virtual table interface.
9974**
9975** If this interface is invoked outside the context of an xConnect or
9976** xCreate virtual table method then the behavior is undefined.
9977**
9978** In the call sqlite3_vtab_config(D,C,...) the D parameter is the
9979** [database connection] in which the virtual table is being created and
9980** which is passed in as the first argument to the [xConnect] or [xCreate]
9981** method that is invoking sqlite3_vtab_config(). The C parameter is one
9982** of the [virtual table configuration options]. The presence and meaning
9983** of parameters after C depend on which [virtual table configuration option]
9984** is used.
9985*/
9986SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...);
9987
9988/*
9989** CAPI3REF: Virtual Table Configuration Options
9990** KEYWORDS: {virtual table configuration options}
9991** KEYWORDS: {virtual table configuration option}
9992**
9993** These macros define the various options to the
9994** [sqlite3_vtab_config()] interface that [virtual table] implementations
9995** can use to customize and optimize their behavior.
9996**
9997** <dl>
9998** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]]
9999** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt>
10000** <dd>Calls of the form
10001** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported,
10002** where X is an integer. If X is zero, then the [virtual table] whose
10003** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not
10004** support constraints. In this configuration (which is the default) if
10005** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire
10006** statement is rolled back as if [ON CONFLICT | OR ABORT] had been
10007** specified as part of the users SQL statement, regardless of the actual
10008** ON CONFLICT mode specified.
10009**
10010** If X is non-zero, then the virtual table implementation guarantees
10011** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before
10012** any modifications to internal or persistent data structures have been made.
10013** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite
10014** is able to roll back a statement or database transaction, and abandon
10015** or continue processing the current SQL statement as appropriate.
10016** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns
10017** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode
10018** had been ABORT.
10019**
10020** Virtual table implementations that are required to handle OR REPLACE
10021** must do so within the [xUpdate] method. If a call to the
10022** [sqlite3_vtab_on_conflict()] function indicates that the current ON
10023** CONFLICT policy is REPLACE, the virtual table implementation should
10024** silently replace the appropriate rows within the xUpdate callback and
10025** return SQLITE_OK. Or, if this is not possible, it may return
10026** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT
10027** constraint handling.
10028** </dd>
10029**
10030** [[SQLITE_VTAB_DIRECTONLY]]<dt>SQLITE_VTAB_DIRECTONLY</dt>
10031** <dd>Calls of the form
10032** [sqlite3_vtab_config](db,SQLITE_VTAB_DIRECTONLY) from within the
10033** the [xConnect] or [xCreate] methods of a [virtual table] implementation
10034** prohibits that virtual table from being used from within triggers and
10035** views.
10036** </dd>
10037**
10038** [[SQLITE_VTAB_INNOCUOUS]]<dt>SQLITE_VTAB_INNOCUOUS</dt>
10039** <dd>Calls of the form
10040** [sqlite3_vtab_config](db,SQLITE_VTAB_INNOCUOUS) from within the
10041** the [xConnect] or [xCreate] methods of a [virtual table] implementation
10042** identify that virtual table as being safe to use from within triggers
10043** and views. Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the
10044** virtual table can do no serious harm even if it is controlled by a
10045** malicious hacker. Developers should avoid setting the SQLITE_VTAB_INNOCUOUS
10046** flag unless absolutely necessary.
10047** </dd>
10048**
10049** [[SQLITE_VTAB_USES_ALL_SCHEMAS]]<dt>SQLITE_VTAB_USES_ALL_SCHEMAS</dt>
10050** <dd>Calls of the form
10051** [sqlite3_vtab_config](db,SQLITE_VTAB_USES_ALL_SCHEMA) from within the
10052** the [xConnect] or [xCreate] methods of a [virtual table] implementation
10053** instruct the query planner to begin at least a read transaction on
10054** all schemas ("main", "temp", and any ATTACH-ed databases) whenever the
10055** virtual table is used.
10056** </dd>
10057** </dl>
10058*/
10059#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1
10060#define SQLITE_VTAB_INNOCUOUS 2
10061#define SQLITE_VTAB_DIRECTONLY 3
10062#define SQLITE_VTAB_USES_ALL_SCHEMAS 4
10063
10064/*
10065** CAPI3REF: Determine The Virtual Table Conflict Policy
10066**
10067** This function may only be called from within a call to the [xUpdate] method
10068** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The
10069** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],
10070** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode
10071** of the SQL statement that triggered the call to the [xUpdate] method of the
10072** [virtual table].
10073*/
10074SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *);
10075
10076/*
10077** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE
10078**
10079** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn]
10080** method of a [virtual table], then it might return true if the
10081** column is being fetched as part of an UPDATE operation during which the
10082** column value will not change. The virtual table implementation can use
10083** this hint as permission to substitute a return value that is less
10084** expensive to compute and that the corresponding
10085** [xUpdate] method understands as a "no-change" value.
10086**
10087** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that
10088** the column is not changed by the UPDATE statement, then the xColumn
10089** method can optionally return without setting a result, without calling
10090** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces].
10091** In that case, [sqlite3_value_nochange(X)] will return true for the
10092** same column in the [xUpdate] method.
10093**
10094** The sqlite3_vtab_nochange() routine is an optimization. Virtual table
10095** implementations should continue to give a correct answer even if the
10096** sqlite3_vtab_nochange() interface were to always return false. In the
10097** current implementation, the sqlite3_vtab_nochange() interface does always
10098** returns false for the enhanced [UPDATE FROM] statement.
10099*/
10100SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*);
10101
10102/*
10103** CAPI3REF: Determine The Collation For a Virtual Table Constraint
10104** METHOD: sqlite3_index_info
10105**
10106** This function may only be called from within a call to the [xBestIndex]
10107** method of a [virtual table]. This function returns a pointer to a string
10108** that is the name of the appropriate collation sequence to use for text
10109** comparisons on the constraint identified by its arguments.
10110**
10111** The first argument must be the pointer to the [sqlite3_index_info] object
10112** that is the first parameter to the xBestIndex() method. The second argument
10113** must be an index into the aConstraint[] array belonging to the
10114** sqlite3_index_info structure passed to xBestIndex.
10115**
10116** Important:
10117** The first parameter must be the same pointer that is passed into the
10118** xBestMethod() method. The first parameter may not be a pointer to a
10119** different [sqlite3_index_info] object, even an exact copy.
10120**
10121** The return value is computed as follows:
10122**
10123** <ol>
10124** <li><p> If the constraint comes from a WHERE clause expression that contains
10125** a [COLLATE operator], then the name of the collation specified by
10126** that COLLATE operator is returned.
10127** <li><p> If there is no COLLATE operator, but the column that is the subject
10128** of the constraint specifies an alternative collating sequence via
10129** a [COLLATE clause] on the column definition within the CREATE TABLE
10130** statement that was passed into [sqlite3_declare_vtab()], then the
10131** name of that alternative collating sequence is returned.
10132** <li><p> Otherwise, "BINARY" is returned.
10133** </ol>
10134*/
10135SQLITE_API const char *sqlite3_vtab_collation(sqlite3_index_info*,int);
10136
10137/*
10138** CAPI3REF: Determine if a virtual table query is DISTINCT
10139** METHOD: sqlite3_index_info
10140**
10141** This API may only be used from within an [xBestIndex|xBestIndex method]
10142** of a [virtual table] implementation. The result of calling this
10143** interface from outside of xBestIndex() is undefined and probably harmful.
10144**
10145** ^The sqlite3_vtab_distinct() interface returns an integer between 0 and
10146** 3. The integer returned by sqlite3_vtab_distinct()
10147** gives the virtual table additional information about how the query
10148** planner wants the output to be ordered. As long as the virtual table
10149** can meet the ordering requirements of the query planner, it may set
10150** the "orderByConsumed" flag.
10151**
10152** <ol><li value="0"><p>
10153** ^If the sqlite3_vtab_distinct() interface returns 0, that means
10154** that the query planner needs the virtual table to return all rows in the
10155** sort order defined by the "nOrderBy" and "aOrderBy" fields of the
10156** [sqlite3_index_info] object. This is the default expectation. If the
10157** virtual table outputs all rows in sorted order, then it is always safe for
10158** the xBestIndex method to set the "orderByConsumed" flag, regardless of
10159** the return value from sqlite3_vtab_distinct().
10160** <li value="1"><p>
10161** ^(If the sqlite3_vtab_distinct() interface returns 1, that means
10162** that the query planner does not need the rows to be returned in sorted order
10163** as long as all rows with the same values in all columns identified by the
10164** "aOrderBy" field are adjacent.)^ This mode is used when the query planner
10165** is doing a GROUP BY.
10166** <li value="2"><p>
10167** ^(If the sqlite3_vtab_distinct() interface returns 2, that means
10168** that the query planner does not need the rows returned in any particular
10169** order, as long as rows with the same values in all columns identified
10170** by "aOrderBy" are adjacent.)^ ^(Furthermore, when two or more rows
10171** contain the same values for all columns identified by "colUsed", all but
10172** one such row may optionally be omitted from the result.)^
10173** The virtual table is not required to omit rows that are duplicates
10174** over the "colUsed" columns, but if the virtual table can do that without
10175** too much extra effort, it could potentially help the query to run faster.
10176** This mode is used for a DISTINCT query.
10177** <li value="3"><p>
10178** ^(If the sqlite3_vtab_distinct() interface returns 3, that means the
10179** virtual table must return rows in the order defined by "aOrderBy" as
10180** if the sqlite3_vtab_distinct() interface had returned 0. However if
10181** two or more rows in the result have the same values for all columns
10182** identified by "colUsed", then all but one such row may optionally be
10183** omitted.)^ Like when the return value is 2, the virtual table
10184** is not required to omit rows that are duplicates over the "colUsed"
10185** columns, but if the virtual table can do that without
10186** too much extra effort, it could potentially help the query to run faster.
10187** This mode is used for queries
10188** that have both DISTINCT and ORDER BY clauses.
10189** </ol>
10190**
10191** <p>The following table summarizes the conditions under which the
10192** virtual table is allowed to set the "orderByConsumed" flag based on
10193** the value returned by sqlite3_vtab_distinct(). This table is a
10194** restatement of the previous four paragraphs:
10195**
10196** <table border=1 cellspacing=0 cellpadding=10 width="90%">
10197** <tr>
10198** <td valign="top">sqlite3_vtab_distinct() return value
10199** <td valign="top">Rows are returned in aOrderBy order
10200** <td valign="top">Rows with the same value in all aOrderBy columns are adjacent
10201** <td valign="top">Duplicates over all colUsed columns may be omitted
10202** <tr><td>0<td>yes<td>yes<td>no
10203** <tr><td>1<td>no<td>yes<td>no
10204** <tr><td>2<td>no<td>yes<td>yes
10205** <tr><td>3<td>yes<td>yes<td>yes
10206** </table>
10207**
10208** ^For the purposes of comparing virtual table output values to see if the
10209** values are same value for sorting purposes, two NULL values are considered
10210** to be the same. In other words, the comparison operator is "IS"
10211** (or "IS NOT DISTINCT FROM") and not "==".
10212**
10213** If a virtual table implementation is unable to meet the requirements
10214** specified above, then it must not set the "orderByConsumed" flag in the
10215** [sqlite3_index_info] object or an incorrect answer may result.
10216**
10217** ^A virtual table implementation is always free to return rows in any order
10218** it wants, as long as the "orderByConsumed" flag is not set. ^When the
10219** the "orderByConsumed" flag is unset, the query planner will add extra
10220** [bytecode] to ensure that the final results returned by the SQL query are
10221** ordered correctly. The use of the "orderByConsumed" flag and the
10222** sqlite3_vtab_distinct() interface is merely an optimization. ^Careful
10223** use of the sqlite3_vtab_distinct() interface and the "orderByConsumed"
10224** flag might help queries against a virtual table to run faster. Being
10225** overly aggressive and setting the "orderByConsumed" flag when it is not
10226** valid to do so, on the other hand, might cause SQLite to return incorrect
10227** results.
10228*/
10229SQLITE_API int sqlite3_vtab_distinct(sqlite3_index_info*);
10230
10231/*
10232** CAPI3REF: Identify and handle IN constraints in xBestIndex
10233**
10234** This interface may only be used from within an
10235** [xBestIndex|xBestIndex() method] of a [virtual table] implementation.
10236** The result of invoking this interface from any other context is
10237** undefined and probably harmful.
10238**
10239** ^(A constraint on a virtual table of the form
10240** "[IN operator|column IN (...)]" is
10241** communicated to the xBestIndex method as a
10242** [SQLITE_INDEX_CONSTRAINT_EQ] constraint.)^ If xBestIndex wants to use
10243** this constraint, it must set the corresponding
10244** aConstraintUsage[].argvIndex to a positive integer. ^(Then, under
10245** the usual mode of handling IN operators, SQLite generates [bytecode]
10246** that invokes the [xFilter|xFilter() method] once for each value
10247** on the right-hand side of the IN operator.)^ Thus the virtual table
10248** only sees a single value from the right-hand side of the IN operator
10249** at a time.
10250**
10251** In some cases, however, it would be advantageous for the virtual
10252** table to see all values on the right-hand of the IN operator all at
10253** once. The sqlite3_vtab_in() interfaces facilitates this in two ways:
10254**
10255** <ol>
10256** <li><p>
10257** ^A call to sqlite3_vtab_in(P,N,-1) will return true (non-zero)
10258** if and only if the [sqlite3_index_info|P->aConstraint][N] constraint
10259** is an [IN operator] that can be processed all at once. ^In other words,
10260** sqlite3_vtab_in() with -1 in the third argument is a mechanism
10261** by which the virtual table can ask SQLite if all-at-once processing
10262** of the IN operator is even possible.
10263**
10264** <li><p>
10265** ^A call to sqlite3_vtab_in(P,N,F) with F==1 or F==0 indicates
10266** to SQLite that the virtual table does or does not want to process
10267** the IN operator all-at-once, respectively. ^Thus when the third
10268** parameter (F) is non-negative, this interface is the mechanism by
10269** which the virtual table tells SQLite how it wants to process the
10270** IN operator.
10271** </ol>
10272**
10273** ^The sqlite3_vtab_in(P,N,F) interface can be invoked multiple times
10274** within the same xBestIndex method call. ^For any given P,N pair,
10275** the return value from sqlite3_vtab_in(P,N,F) will always be the same
10276** within the same xBestIndex call. ^If the interface returns true
10277** (non-zero), that means that the constraint is an IN operator
10278** that can be processed all-at-once. ^If the constraint is not an IN
10279** operator or cannot be processed all-at-once, then the interface returns
10280** false.
10281**
10282** ^(All-at-once processing of the IN operator is selected if both of the
10283** following conditions are met:
10284**
10285** <ol>
10286** <li><p> The P->aConstraintUsage[N].argvIndex value is set to a positive
10287** integer. This is how the virtual table tells SQLite that it wants to
10288** use the N-th constraint.
10289**
10290** <li><p> The last call to sqlite3_vtab_in(P,N,F) for which F was
10291** non-negative had F>=1.
10292** </ol>)^
10293**
10294** ^If either or both of the conditions above are false, then SQLite uses
10295** the traditional one-at-a-time processing strategy for the IN constraint.
10296** ^If both conditions are true, then the argvIndex-th parameter to the
10297** xFilter method will be an [sqlite3_value] that appears to be NULL,
10298** but which can be passed to [sqlite3_vtab_in_first()] and
10299** [sqlite3_vtab_in_next()] to find all values on the right-hand side
10300** of the IN constraint.
10301*/
10302SQLITE_API int sqlite3_vtab_in(sqlite3_index_info*, int iCons, int bHandle);
10303
10304/*
10305** CAPI3REF: Find all elements on the right-hand side of an IN constraint.
10306**
10307** These interfaces are only useful from within the
10308** [xFilter|xFilter() method] of a [virtual table] implementation.
10309** The result of invoking these interfaces from any other context
10310** is undefined and probably harmful.
10311**
10312** The X parameter in a call to sqlite3_vtab_in_first(X,P) or
10313** sqlite3_vtab_in_next(X,P) should be one of the parameters to the
10314** xFilter method which invokes these routines, and specifically
10315** a parameter that was previously selected for all-at-once IN constraint
10316** processing use the [sqlite3_vtab_in()] interface in the
10317** [xBestIndex|xBestIndex method]. ^(If the X parameter is not
10318** an xFilter argument that was selected for all-at-once IN constraint
10319** processing, then these routines return [SQLITE_ERROR].)^
10320**
10321** ^(Use these routines to access all values on the right-hand side
10322** of the IN constraint using code like the following:
10323**
10324** <blockquote><pre>
10325** for(rc=sqlite3_vtab_in_first(pList, &pVal);
10326** rc==SQLITE_OK && pVal;
10327** rc=sqlite3_vtab_in_next(pList, &pVal)
10328** ){
10329** // do something with pVal
10330** }
10331** if( rc!=SQLITE_OK ){
10332** // an error has occurred
10333** }
10334** </pre></blockquote>)^
10335**
10336** ^On success, the sqlite3_vtab_in_first(X,P) and sqlite3_vtab_in_next(X,P)
10337** routines return SQLITE_OK and set *P to point to the first or next value
10338** on the RHS of the IN constraint. ^If there are no more values on the
10339** right hand side of the IN constraint, then *P is set to NULL and these
10340** routines return [SQLITE_DONE]. ^The return value might be
10341** some other value, such as SQLITE_NOMEM, in the event of a malfunction.
10342**
10343** The *ppOut values returned by these routines are only valid until the
10344** next call to either of these routines or until the end of the xFilter
10345** method from which these routines were called. If the virtual table
10346** implementation needs to retain the *ppOut values for longer, it must make
10347** copies. The *ppOut values are [protected sqlite3_value|protected].
10348*/
10349SQLITE_API int sqlite3_vtab_in_first(sqlite3_value *pVal, sqlite3_value **ppOut);
10350SQLITE_API int sqlite3_vtab_in_next(sqlite3_value *pVal, sqlite3_value **ppOut);
10351
10352/*
10353** CAPI3REF: Constraint values in xBestIndex()
10354** METHOD: sqlite3_index_info
10355**
10356** This API may only be used from within the [xBestIndex|xBestIndex method]
10357** of a [virtual table] implementation. The result of calling this interface
10358** from outside of an xBestIndex method are undefined and probably harmful.
10359**
10360** ^When the sqlite3_vtab_rhs_value(P,J,V) interface is invoked from within
10361** the [xBestIndex] method of a [virtual table] implementation, with P being
10362** a copy of the [sqlite3_index_info] object pointer passed into xBestIndex and
10363** J being a 0-based index into P->aConstraint[], then this routine
10364** attempts to set *V to the value of the right-hand operand of
10365** that constraint if the right-hand operand is known. ^If the
10366** right-hand operand is not known, then *V is set to a NULL pointer.
10367** ^The sqlite3_vtab_rhs_value(P,J,V) interface returns SQLITE_OK if
10368** and only if *V is set to a value. ^The sqlite3_vtab_rhs_value(P,J,V)
10369** inteface returns SQLITE_NOTFOUND if the right-hand side of the J-th
10370** constraint is not available. ^The sqlite3_vtab_rhs_value() interface
10371** can return an result code other than SQLITE_OK or SQLITE_NOTFOUND if
10372** something goes wrong.
10373**
10374** The sqlite3_vtab_rhs_value() interface is usually only successful if
10375** the right-hand operand of a constraint is a literal value in the original
10376** SQL statement. If the right-hand operand is an expression or a reference
10377** to some other column or a [host parameter], then sqlite3_vtab_rhs_value()
10378** will probably return [SQLITE_NOTFOUND].
10379**
10380** ^(Some constraints, such as [SQLITE_INDEX_CONSTRAINT_ISNULL] and
10381** [SQLITE_INDEX_CONSTRAINT_ISNOTNULL], have no right-hand operand. For such
10382** constraints, sqlite3_vtab_rhs_value() always returns SQLITE_NOTFOUND.)^
10383**
10384** ^The [sqlite3_value] object returned in *V is a protected sqlite3_value
10385** and remains valid for the duration of the xBestIndex method call.
10386** ^When xBestIndex returns, the sqlite3_value object returned by
10387** sqlite3_vtab_rhs_value() is automatically deallocated.
10388**
10389** The "_rhs_" in the name of this routine is an abbreviation for
10390** "Right-Hand Side".
10391*/
10392SQLITE_API int sqlite3_vtab_rhs_value(sqlite3_index_info*, int, sqlite3_value **ppVal);
10393
10394/*
10395** CAPI3REF: Conflict resolution modes
10396** KEYWORDS: {conflict resolution mode}
10397**
10398** These constants are returned by [sqlite3_vtab_on_conflict()] to
10399** inform a [virtual table] implementation what the [ON CONFLICT] mode
10400** is for the SQL statement being evaluated.
10401**
10402** Note that the [SQLITE_IGNORE] constant is also used as a potential
10403** return value from the [sqlite3_set_authorizer()] callback and that
10404** [SQLITE_ABORT] is also a [result code].
10405*/
10406#define SQLITE_ROLLBACK 1
10407/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */
10408#define SQLITE_FAIL 3
10409/* #define SQLITE_ABORT 4 // Also an error code */
10410#define SQLITE_REPLACE 5
10411
10412/*
10413** CAPI3REF: Prepared Statement Scan Status Opcodes
10414** KEYWORDS: {scanstatus options}
10415**
10416** The following constants can be used for the T parameter to the
10417** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a
10418** different metric for sqlite3_stmt_scanstatus() to return.
10419**
10420** When the value returned to V is a string, space to hold that string is
10421** managed by the prepared statement S and will be automatically freed when
10422** S is finalized.
10423**
10424** Not all values are available for all query elements. When a value is
10425** not available, the output variable is set to -1 if the value is numeric,
10426** or to NULL if it is a string (SQLITE_SCANSTAT_NAME).
10427**
10428** <dl>
10429** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt>
10430** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be
10431** set to the total number of times that the X-th loop has run.</dd>
10432**
10433** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt>
10434** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set
10435** to the total number of rows examined by all iterations of the X-th loop.</dd>
10436**
10437** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt>
10438** <dd>^The "double" variable pointed to by the V parameter will be set to the
10439** query planner's estimate for the average number of rows output from each
10440** iteration of the X-th loop. If the query planner's estimates was accurate,
10441** then this value will approximate the quotient NVISIT/NLOOP and the
10442** product of this value for all prior loops with the same SELECTID will
10443** be the NLOOP value for the current loop.
10444**
10445** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt>
10446** <dd>^The "const char *" variable pointed to by the V parameter will be set
10447** to a zero-terminated UTF-8 string containing the name of the index or table
10448** used for the X-th loop.
10449**
10450** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt>
10451** <dd>^The "const char *" variable pointed to by the V parameter will be set
10452** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN]
10453** description for the X-th loop.
10454**
10455** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECTID</dt>
10456** <dd>^The "int" variable pointed to by the V parameter will be set to the
10457** id for the X-th query plan element. The id value is unique within the
10458** statement. The select-id is the same value as is output in the first
10459** column of an [EXPLAIN QUERY PLAN] query.
10460**
10461** [[SQLITE_SCANSTAT_PARENTID]] <dt>SQLITE_SCANSTAT_PARENTID</dt>
10462** <dd>The "int" variable pointed to by the V parameter will be set to the
10463** the id of the parent of the current query element, if applicable, or
10464** to zero if the query element has no parent. This is the same value as
10465** returned in the second column of an [EXPLAIN QUERY PLAN] query.
10466**
10467** [[SQLITE_SCANSTAT_NCYCLE]] <dt>SQLITE_SCANSTAT_NCYCLE</dt>
10468** <dd>The sqlite3_int64 output value is set to the number of cycles,
10469** according to the processor time-stamp counter, that elapsed while the
10470** query element was being processed. This value is not available for
10471** all query elements - if it is unavailable the output variable is
10472** set to -1.
10473** </dl>
10474*/
10475#define SQLITE_SCANSTAT_NLOOP 0
10476#define SQLITE_SCANSTAT_NVISIT 1
10477#define SQLITE_SCANSTAT_EST 2
10478#define SQLITE_SCANSTAT_NAME 3
10479#define SQLITE_SCANSTAT_EXPLAIN 4
10480#define SQLITE_SCANSTAT_SELECTID 5
10481#define SQLITE_SCANSTAT_PARENTID 6
10482#define SQLITE_SCANSTAT_NCYCLE 7
10483
10484/*
10485** CAPI3REF: Prepared Statement Scan Status
10486** METHOD: sqlite3_stmt
10487**
10488** These interfaces return information about the predicted and measured
10489** performance for pStmt. Advanced applications can use this
10490** interface to compare the predicted and the measured performance and
10491** issue warnings and/or rerun [ANALYZE] if discrepancies are found.
10492**
10493** Since this interface is expected to be rarely used, it is only
10494** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS]
10495** compile-time option.
10496**
10497** The "iScanStatusOp" parameter determines which status information to return.
10498** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior
10499** of this interface is undefined. ^The requested measurement is written into
10500** a variable pointed to by the "pOut" parameter.
10501**
10502** The "flags" parameter must be passed a mask of flags. At present only
10503** one flag is defined - SQLITE_SCANSTAT_COMPLEX. If SQLITE_SCANSTAT_COMPLEX
10504** is specified, then status information is available for all elements
10505** of a query plan that are reported by "EXPLAIN QUERY PLAN" output. If
10506** SQLITE_SCANSTAT_COMPLEX is not specified, then only query plan elements
10507** that correspond to query loops (the "SCAN..." and "SEARCH..." elements of
10508** the EXPLAIN QUERY PLAN output) are available. Invoking API
10509** sqlite3_stmt_scanstatus() is equivalent to calling
10510** sqlite3_stmt_scanstatus_v2() with a zeroed flags parameter.
10511**
10512** Parameter "idx" identifies the specific query element to retrieve statistics
10513** for. Query elements are numbered starting from zero. A value of -1 may be
10514** to query for statistics regarding the entire query. ^If idx is out of range
10515** - less than -1 or greater than or equal to the total number of query
10516** elements used to implement the statement - a non-zero value is returned and
10517** the variable that pOut points to is unchanged.
10518**
10519** See also: [sqlite3_stmt_scanstatus_reset()]
10520*/
10521SQLITE_API int sqlite3_stmt_scanstatus(
10522 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */
10523 int idx, /* Index of loop to report on */
10524 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */
10525 void *pOut /* Result written here */
10526);
10527SQLITE_API int sqlite3_stmt_scanstatus_v2(
10528 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */
10529 int idx, /* Index of loop to report on */
10530 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */
10531 int flags, /* Mask of flags defined below */
10532 void *pOut /* Result written here */
10533);
10534
10535/*
10536** CAPI3REF: Prepared Statement Scan Status
10537** KEYWORDS: {scan status flags}
10538*/
10539#define SQLITE_SCANSTAT_COMPLEX 0x0001
10540
10541/*
10542** CAPI3REF: Zero Scan-Status Counters
10543** METHOD: sqlite3_stmt
10544**
10545** ^Zero all [sqlite3_stmt_scanstatus()] related event counters.
10546**
10547** This API is only available if the library is built with pre-processor
10548** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined.
10549*/
10550SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*);
10551
10552/*
10553** CAPI3REF: Flush caches to disk mid-transaction
10554** METHOD: sqlite3
10555**
10556** ^If a write-transaction is open on [database connection] D when the
10557** [sqlite3_db_cacheflush(D)] interface is invoked, any dirty
10558** pages in the pager-cache that are not currently in use are written out
10559** to disk. A dirty page may be in use if a database cursor created by an
10560** active SQL statement is reading from it, or if it is page 1 of a database
10561** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)]
10562** interface flushes caches for all schemas - "main", "temp", and
10563** any [attached] databases.
10564**
10565** ^If this function needs to obtain extra database locks before dirty pages
10566** can be flushed to disk, it does so. ^If those locks cannot be obtained
10567** immediately and there is a busy-handler callback configured, it is invoked
10568** in the usual manner. ^If the required lock still cannot be obtained, then
10569** the database is skipped and an attempt made to flush any dirty pages
10570** belonging to the next (if any) database. ^If any databases are skipped
10571** because locks cannot be obtained, but no other error occurs, this
10572** function returns SQLITE_BUSY.
10573**
10574** ^If any other error occurs while flushing dirty pages to disk (for
10575** example an IO error or out-of-memory condition), then processing is
10576** abandoned and an SQLite [error code] is returned to the caller immediately.
10577**
10578** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK.
10579**
10580** ^This function does not set the database handle error code or message
10581** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions.
10582*/
10583SQLITE_API int sqlite3_db_cacheflush(sqlite3*);
10584
10585/*
10586** CAPI3REF: The pre-update hook.
10587** METHOD: sqlite3
10588**
10589** ^These interfaces are only available if SQLite is compiled using the
10590** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option.
10591**
10592** ^The [sqlite3_preupdate_hook()] interface registers a callback function
10593** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation
10594** on a database table.
10595** ^At most one preupdate hook may be registered at a time on a single
10596** [database connection]; each call to [sqlite3_preupdate_hook()] overrides
10597** the previous setting.
10598** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()]
10599** with a NULL pointer as the second parameter.
10600** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as
10601** the first parameter to callbacks.
10602**
10603** ^The preupdate hook only fires for changes to real database tables; the
10604** preupdate hook is not invoked for changes to [virtual tables] or to
10605** system tables like sqlite_sequence or sqlite_stat1.
10606**
10607** ^The second parameter to the preupdate callback is a pointer to
10608** the [database connection] that registered the preupdate hook.
10609** ^The third parameter to the preupdate callback is one of the constants
10610** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the
10611** kind of update operation that is about to occur.
10612** ^(The fourth parameter to the preupdate callback is the name of the
10613** database within the database connection that is being modified. This
10614** will be "main" for the main database or "temp" for TEMP tables or
10615** the name given after the AS keyword in the [ATTACH] statement for attached
10616** databases.)^
10617** ^The fifth parameter to the preupdate callback is the name of the
10618** table that is being modified.
10619**
10620** For an UPDATE or DELETE operation on a [rowid table], the sixth
10621** parameter passed to the preupdate callback is the initial [rowid] of the
10622** row being modified or deleted. For an INSERT operation on a rowid table,
10623** or any operation on a WITHOUT ROWID table, the value of the sixth
10624** parameter is undefined. For an INSERT or UPDATE on a rowid table the
10625** seventh parameter is the final rowid value of the row being inserted
10626** or updated. The value of the seventh parameter passed to the callback
10627** function is not defined for operations on WITHOUT ROWID tables, or for
10628** DELETE operations on rowid tables.
10629**
10630** ^The sqlite3_preupdate_hook(D,C,P) function returns the P argument from
10631** the previous call on the same [database connection] D, or NULL for
10632** the first call on D.
10633**
10634** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()],
10635** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces
10636** provide additional information about a preupdate event. These routines
10637** may only be called from within a preupdate callback. Invoking any of
10638** these routines from outside of a preupdate callback or with a
10639** [database connection] pointer that is different from the one supplied
10640** to the preupdate callback results in undefined and probably undesirable
10641** behavior.
10642**
10643** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns
10644** in the row that is being inserted, updated, or deleted.
10645**
10646** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to
10647** a [protected sqlite3_value] that contains the value of the Nth column of
10648** the table row before it is updated. The N parameter must be between 0
10649** and one less than the number of columns or the behavior will be
10650** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE
10651** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the
10652** behavior is undefined. The [sqlite3_value] that P points to
10653** will be destroyed when the preupdate callback returns.
10654**
10655** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to
10656** a [protected sqlite3_value] that contains the value of the Nth column of
10657** the table row after it is updated. The N parameter must be between 0
10658** and one less than the number of columns or the behavior will be
10659** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE
10660** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the
10661** behavior is undefined. The [sqlite3_value] that P points to
10662** will be destroyed when the preupdate callback returns.
10663**
10664** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate
10665** callback was invoked as a result of a direct insert, update, or delete
10666** operation; or 1 for inserts, updates, or deletes invoked by top-level
10667** triggers; or 2 for changes resulting from triggers called by top-level
10668** triggers; and so forth.
10669**
10670** When the [sqlite3_blob_write()] API is used to update a blob column,
10671** the pre-update hook is invoked with SQLITE_DELETE. This is because the
10672** in this case the new values are not available. In this case, when a
10673** callback made with op==SQLITE_DELETE is actually a write using the
10674** sqlite3_blob_write() API, the [sqlite3_preupdate_blobwrite()] returns
10675** the index of the column being written. In other cases, where the
10676** pre-update hook is being invoked for some other reason, including a
10677** regular DELETE, sqlite3_preupdate_blobwrite() returns -1.
10678**
10679** See also: [sqlite3_update_hook()]
10680*/
10681#if defined(SQLITE_ENABLE_PREUPDATE_HOOK)
10682SQLITE_API void *sqlite3_preupdate_hook(
10683 sqlite3 *db,
10684 void(*xPreUpdate)(
10685 void *pCtx, /* Copy of third arg to preupdate_hook() */
10686 sqlite3 *db, /* Database handle */
10687 int op, /* SQLITE_UPDATE, DELETE or INSERT */
10688 char const *zDb, /* Database name */
10689 char const *zName, /* Table name */
10690 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */
10691 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */
10692 ),
10693 void*
10694);
10695SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **);
10696SQLITE_API int sqlite3_preupdate_count(sqlite3 *);
10697SQLITE_API int sqlite3_preupdate_depth(sqlite3 *);
10698SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **);
10699SQLITE_API int sqlite3_preupdate_blobwrite(sqlite3 *);
10700#endif
10701
10702/*
10703** CAPI3REF: Low-level system error code
10704** METHOD: sqlite3
10705**
10706** ^Attempt to return the underlying operating system error code or error
10707** number that caused the most recent I/O error or failure to open a file.
10708** The return value is OS-dependent. For example, on unix systems, after
10709** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be
10710** called to get back the underlying "errno" that caused the problem, such
10711** as ENOSPC, EAUTH, EISDIR, and so forth.
10712*/
10713SQLITE_API int sqlite3_system_errno(sqlite3*);
10714
10715/*
10716** CAPI3REF: Database Snapshot
10717** KEYWORDS: {snapshot} {sqlite3_snapshot}
10718**
10719** An instance of the snapshot object records the state of a [WAL mode]
10720** database for some specific point in history.
10721**
10722** In [WAL mode], multiple [database connections] that are open on the
10723** same database file can each be reading a different historical version
10724** of the database file. When a [database connection] begins a read
10725** transaction, that connection sees an unchanging copy of the database
10726** as it existed for the point in time when the transaction first started.
10727** Subsequent changes to the database from other connections are not seen
10728** by the reader until a new read transaction is started.
10729**
10730** The sqlite3_snapshot object records state information about an historical
10731** version of the database file so that it is possible to later open a new read
10732** transaction that sees that historical version of the database rather than
10733** the most recent version.
10734*/
10735typedef struct sqlite3_snapshot {
10736 unsigned char hidden[48];
10737} sqlite3_snapshot;
10738
10739/*
10740** CAPI3REF: Record A Database Snapshot
10741** CONSTRUCTOR: sqlite3_snapshot
10742**
10743** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a
10744** new [sqlite3_snapshot] object that records the current state of
10745** schema S in database connection D. ^On success, the
10746** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly
10747** created [sqlite3_snapshot] object into *P and returns SQLITE_OK.
10748** If there is not already a read-transaction open on schema S when
10749** this function is called, one is opened automatically.
10750**
10751** If a read-transaction is opened by this function, then it is guaranteed
10752** that the returned snapshot object may not be invalidated by a database
10753** writer or checkpointer until after the read-transaction is closed. This
10754** is not guaranteed if a read-transaction is already open when this
10755** function is called. In that case, any subsequent write or checkpoint
10756** operation on the database may invalidate the returned snapshot handle,
10757** even while the read-transaction remains open.
10758**
10759** The following must be true for this function to succeed. If any of
10760** the following statements are false when sqlite3_snapshot_get() is
10761** called, SQLITE_ERROR is returned. The final value of *P is undefined
10762** in this case.
10763**
10764** <ul>
10765** <li> The database handle must not be in [autocommit mode].
10766**
10767** <li> Schema S of [database connection] D must be a [WAL mode] database.
10768**
10769** <li> There must not be a write transaction open on schema S of database
10770** connection D.
10771**
10772** <li> One or more transactions must have been written to the current wal
10773** file since it was created on disk (by any connection). This means
10774** that a snapshot cannot be taken on a wal mode database with no wal
10775** file immediately after it is first opened. At least one transaction
10776** must be written to it first.
10777** </ul>
10778**
10779** This function may also return SQLITE_NOMEM. If it is called with the
10780** database handle in autocommit mode but fails for some other reason,
10781** whether or not a read transaction is opened on schema S is undefined.
10782**
10783** The [sqlite3_snapshot] object returned from a successful call to
10784** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()]
10785** to avoid a memory leak.
10786**
10787** The [sqlite3_snapshot_get()] interface is only available when the
10788** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
10789*/
10790SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get(
10791 sqlite3 *db,
10792 const char *zSchema,
10793 sqlite3_snapshot **ppSnapshot
10794);
10795
10796/*
10797** CAPI3REF: Start a read transaction on an historical snapshot
10798** METHOD: sqlite3_snapshot
10799**
10800** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read
10801** transaction or upgrades an existing one for schema S of
10802** [database connection] D such that the read transaction refers to
10803** historical [snapshot] P, rather than the most recent change to the
10804** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK
10805** on success or an appropriate [error code] if it fails.
10806**
10807** ^In order to succeed, the database connection must not be in
10808** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there
10809** is already a read transaction open on schema S, then the database handle
10810** must have no active statements (SELECT statements that have been passed
10811** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()).
10812** SQLITE_ERROR is returned if either of these conditions is violated, or
10813** if schema S does not exist, or if the snapshot object is invalid.
10814**
10815** ^A call to sqlite3_snapshot_open() will fail to open if the specified
10816** snapshot has been overwritten by a [checkpoint]. In this case
10817** SQLITE_ERROR_SNAPSHOT is returned.
10818**
10819** If there is already a read transaction open when this function is
10820** invoked, then the same read transaction remains open (on the same
10821** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT
10822** is returned. If another error code - for example SQLITE_PROTOCOL or an
10823** SQLITE_IOERR error code - is returned, then the final state of the
10824** read transaction is undefined. If SQLITE_OK is returned, then the
10825** read transaction is now open on database snapshot P.
10826**
10827** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the
10828** database connection D does not know that the database file for
10829** schema S is in [WAL mode]. A database connection might not know
10830** that the database file is in [WAL mode] if there has been no prior
10831** I/O on that database connection, or if the database entered [WAL mode]
10832** after the most recent I/O on the database connection.)^
10833** (Hint: Run "[PRAGMA application_id]" against a newly opened
10834** database connection in order to make it ready to use snapshots.)
10835**
10836** The [sqlite3_snapshot_open()] interface is only available when the
10837** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
10838*/
10839SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open(
10840 sqlite3 *db,
10841 const char *zSchema,
10842 sqlite3_snapshot *pSnapshot
10843);
10844
10845/*
10846** CAPI3REF: Destroy a snapshot
10847** DESTRUCTOR: sqlite3_snapshot
10848**
10849** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P.
10850** The application must eventually free every [sqlite3_snapshot] object
10851** using this routine to avoid a memory leak.
10852**
10853** The [sqlite3_snapshot_free()] interface is only available when the
10854** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
10855*/
10856SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*);
10857
10858/*
10859** CAPI3REF: Compare the ages of two snapshot handles.
10860** METHOD: sqlite3_snapshot
10861**
10862** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages
10863** of two valid snapshot handles.
10864**
10865** If the two snapshot handles are not associated with the same database
10866** file, the result of the comparison is undefined.
10867**
10868** Additionally, the result of the comparison is only valid if both of the
10869** snapshot handles were obtained by calling sqlite3_snapshot_get() since the
10870** last time the wal file was deleted. The wal file is deleted when the
10871** database is changed back to rollback mode or when the number of database
10872** clients drops to zero. If either snapshot handle was obtained before the
10873** wal file was last deleted, the value returned by this function
10874** is undefined.
10875**
10876** Otherwise, this API returns a negative value if P1 refers to an older
10877** snapshot than P2, zero if the two handles refer to the same database
10878** snapshot, and a positive value if P1 is a newer snapshot than P2.
10879**
10880** This interface is only available if SQLite is compiled with the
10881** [SQLITE_ENABLE_SNAPSHOT] option.
10882*/
10883SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp(
10884 sqlite3_snapshot *p1,
10885 sqlite3_snapshot *p2
10886);
10887
10888/*
10889** CAPI3REF: Recover snapshots from a wal file
10890** METHOD: sqlite3_snapshot
10891**
10892** If a [WAL file] remains on disk after all database connections close
10893** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control]
10894** or because the last process to have the database opened exited without
10895** calling [sqlite3_close()]) and a new connection is subsequently opened
10896** on that database and [WAL file], the [sqlite3_snapshot_open()] interface
10897** will only be able to open the last transaction added to the WAL file
10898** even though the WAL file contains other valid transactions.
10899**
10900** This function attempts to scan the WAL file associated with database zDb
10901** of database handle db and make all valid snapshots available to
10902** sqlite3_snapshot_open(). It is an error if there is already a read
10903** transaction open on the database, or if the database is not a WAL mode
10904** database.
10905**
10906** SQLITE_OK is returned if successful, or an SQLite error code otherwise.
10907**
10908** This interface is only available if SQLite is compiled with the
10909** [SQLITE_ENABLE_SNAPSHOT] option.
10910*/
10911SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb);
10912
10913/*
10914** CAPI3REF: Serialize a database
10915**
10916** The sqlite3_serialize(D,S,P,F) interface returns a pointer to
10917** memory that is a serialization of the S database on
10918** [database connection] D. If S is a NULL pointer, the main database is used.
10919** If P is not a NULL pointer, then the size of the database in bytes
10920** is written into *P.
10921**
10922** For an ordinary on-disk database file, the serialization is just a
10923** copy of the disk file. For an in-memory database or a "TEMP" database,
10924** the serialization is the same sequence of bytes which would be written
10925** to disk if that database where backed up to disk.
10926**
10927** The usual case is that sqlite3_serialize() copies the serialization of
10928** the database into memory obtained from [sqlite3_malloc64()] and returns
10929** a pointer to that memory. The caller is responsible for freeing the
10930** returned value to avoid a memory leak. However, if the F argument
10931** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations
10932** are made, and the sqlite3_serialize() function will return a pointer
10933** to the contiguous memory representation of the database that SQLite
10934** is currently using for that database, or NULL if the no such contiguous
10935** memory representation of the database exists. A contiguous memory
10936** representation of the database will usually only exist if there has
10937** been a prior call to [sqlite3_deserialize(D,S,...)] with the same
10938** values of D and S.
10939** The size of the database is written into *P even if the
10940** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy
10941** of the database exists.
10942**
10943** After the call, if the SQLITE_SERIALIZE_NOCOPY bit had been set,
10944** the returned buffer content will remain accessible and unchanged
10945** until either the next write operation on the connection or when
10946** the connection is closed, and applications must not modify the
10947** buffer. If the bit had been clear, the returned buffer will not
10948** be accessed by SQLite after the call.
10949**
10950** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the
10951** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory
10952** allocation error occurs.
10953**
10954** This interface is omitted if SQLite is compiled with the
10955** [SQLITE_OMIT_DESERIALIZE] option.
10956*/
10957SQLITE_API unsigned char *sqlite3_serialize(
10958 sqlite3 *db, /* The database connection */
10959 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */
10960 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */
10961 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */
10962);
10963
10964/*
10965** CAPI3REF: Flags for sqlite3_serialize
10966**
10967** Zero or more of the following constants can be OR-ed together for
10968** the F argument to [sqlite3_serialize(D,S,P,F)].
10969**
10970** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return
10971** a pointer to contiguous in-memory database that it is currently using,
10972** without making a copy of the database. If SQLite is not currently using
10973** a contiguous in-memory database, then this option causes
10974** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be
10975** using a contiguous in-memory database if it has been initialized by a
10976** prior call to [sqlite3_deserialize()].
10977*/
10978#define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */
10979
10980/*
10981** CAPI3REF: Deserialize a database
10982**
10983** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the
10984** [database connection] D to disconnect from database S and then
10985** reopen S as an in-memory database based on the serialization contained
10986** in P. The serialized database P is N bytes in size. M is the size of
10987** the buffer P, which might be larger than N. If M is larger than N, and
10988** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is
10989** permitted to add content to the in-memory database as long as the total
10990** size does not exceed M bytes.
10991**
10992** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will
10993** invoke sqlite3_free() on the serialization buffer when the database
10994** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then
10995** SQLite will try to increase the buffer size using sqlite3_realloc64()
10996** if writes on the database cause it to grow larger than M bytes.
10997**
10998** Applications must not modify the buffer P or invalidate it before
10999** the database connection D is closed.
11000**
11001** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the
11002** database is currently in a read transaction or is involved in a backup
11003** operation.
11004**
11005** It is not possible to deserialized into the TEMP database. If the
11006** S argument to sqlite3_deserialize(D,S,P,N,M,F) is "temp" then the
11007** function returns SQLITE_ERROR.
11008**
11009** The deserialized database should not be in [WAL mode]. If the database
11010** is in WAL mode, then any attempt to use the database file will result
11011** in an [SQLITE_CANTOPEN] error. The application can set the
11012** [file format version numbers] (bytes 18 and 19) of the input database P
11013** to 0x01 prior to invoking sqlite3_deserialize(D,S,P,N,M,F) to force the
11014** database file into rollback mode and work around this limitation.
11015**
11016** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the
11017** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then
11018** [sqlite3_free()] is invoked on argument P prior to returning.
11019**
11020** This interface is omitted if SQLite is compiled with the
11021** [SQLITE_OMIT_DESERIALIZE] option.
11022*/
11023SQLITE_API int sqlite3_deserialize(
11024 sqlite3 *db, /* The database connection */
11025 const char *zSchema, /* Which DB to reopen with the deserialization */
11026 unsigned char *pData, /* The serialized database content */
11027 sqlite3_int64 szDb, /* Number bytes in the deserialization */
11028 sqlite3_int64 szBuf, /* Total size of buffer pData[] */
11029 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */
11030);
11031
11032/*
11033** CAPI3REF: Flags for sqlite3_deserialize()
11034**
11035** The following are allowed values for 6th argument (the F argument) to
11036** the [sqlite3_deserialize(D,S,P,N,M,F)] interface.
11037**
11038** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization
11039** in the P argument is held in memory obtained from [sqlite3_malloc64()]
11040** and that SQLite should take ownership of this memory and automatically
11041** free it when it has finished using it. Without this flag, the caller
11042** is responsible for freeing any dynamically allocated memory.
11043**
11044** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to
11045** grow the size of the database using calls to [sqlite3_realloc64()]. This
11046** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used.
11047** Without this flag, the deserialized database cannot increase in size beyond
11048** the number of bytes specified by the M parameter.
11049**
11050** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database
11051** should be treated as read-only.
11052*/
11053#define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */
11054#define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */
11055#define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */
11056
11057/*
11058** Undo the hack that converts floating point types to integer for
11059** builds on processors without floating point support.
11060*/
11061#ifdef SQLITE_OMIT_FLOATING_POINT
11062# undef double
11063#endif
11064
11065#if defined(__wasi__)
11066# undef SQLITE_WASI
11067# define SQLITE_WASI 1
11068# ifndef SQLITE_OMIT_LOAD_EXTENSION
11069# define SQLITE_OMIT_LOAD_EXTENSION
11070# endif
11071# ifndef SQLITE_THREADSAFE
11072# define SQLITE_THREADSAFE 0
11073# endif
11074#endif
11075
11076#ifdef __cplusplus
11077} /* End of the 'extern "C"' block */
11078#endif
11079/* #endif for SQLITE3_H will be added by mksqlite3.tcl */
11080
11081/******** Begin file sqlite3rtree.h *********/
11082/*
11083** 2010 August 30
11084**
11085** The author disclaims copyright to this source code. In place of
11086** a legal notice, here is a blessing:
11087**
11088** May you do good and not evil.
11089** May you find forgiveness for yourself and forgive others.
11090** May you share freely, never taking more than you give.
11091**
11092*************************************************************************
11093*/
11094
11095#ifndef _SQLITE3RTREE_H_
11096#define _SQLITE3RTREE_H_
11097
11098
11099#ifdef __cplusplus
11100extern "C" {
11101#endif
11102
11103typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
11104typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info;
11105
11106/* The double-precision datatype used by RTree depends on the
11107** SQLITE_RTREE_INT_ONLY compile-time option.
11108*/
11109#ifdef SQLITE_RTREE_INT_ONLY
11110 typedef sqlite3_int64 sqlite3_rtree_dbl;
11111#else
11112 typedef double sqlite3_rtree_dbl;
11113#endif
11114
11115/*
11116** Register a geometry callback named zGeom that can be used as part of an
11117** R-Tree geometry query as follows:
11118**
11119** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
11120*/
11121SQLITE_API int sqlite3_rtree_geometry_callback(
11122 sqlite3 *db,
11123 const char *zGeom,
11124 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*),
11125 void *pContext
11126);
11127
11128
11129/*
11130** A pointer to a structure of the following type is passed as the first
11131** argument to callbacks registered using rtree_geometry_callback().
11132*/
11133struct sqlite3_rtree_geometry {
11134 void *pContext; /* Copy of pContext passed to s_r_g_c() */
11135 int nParam; /* Size of array aParam[] */
11136 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */
11137 void *pUser; /* Callback implementation user data */
11138 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */
11139};
11140
11141/*
11142** Register a 2nd-generation geometry callback named zScore that can be
11143** used as part of an R-Tree geometry query as follows:
11144**
11145** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...)
11146*/
11147SQLITE_API int sqlite3_rtree_query_callback(
11148 sqlite3 *db,
11149 const char *zQueryFunc,
11150 int (*xQueryFunc)(sqlite3_rtree_query_info*),
11151 void *pContext,
11152 void (*xDestructor)(void*)
11153);
11154
11155
11156/*
11157** A pointer to a structure of the following type is passed as the
11158** argument to scored geometry callback registered using
11159** sqlite3_rtree_query_callback().
11160**
11161** Note that the first 5 fields of this structure are identical to
11162** sqlite3_rtree_geometry. This structure is a subclass of
11163** sqlite3_rtree_geometry.
11164*/
11165struct sqlite3_rtree_query_info {
11166 void *pContext; /* pContext from when function registered */
11167 int nParam; /* Number of function parameters */
11168 sqlite3_rtree_dbl *aParam; /* value of function parameters */
11169 void *pUser; /* callback can use this, if desired */
11170 void (*xDelUser)(void*); /* function to free pUser */
11171 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */
11172 unsigned int *anQueue; /* Number of pending entries in the queue */
11173 int nCoord; /* Number of coordinates */
11174 int iLevel; /* Level of current node or entry */
11175 int mxLevel; /* The largest iLevel value in the tree */
11176 sqlite3_int64 iRowid; /* Rowid for current entry */
11177 sqlite3_rtree_dbl rParentScore; /* Score of parent node */
11178 int eParentWithin; /* Visibility of parent node */
11179 int eWithin; /* OUT: Visibility */
11180 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */
11181 /* The following fields are only available in 3.8.11 and later */
11182 sqlite3_value **apSqlParam; /* Original SQL values of parameters */
11183};
11184
11185/*
11186** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin.
11187*/
11188#define NOT_WITHIN 0 /* Object completely outside of query region */
11189#define PARTLY_WITHIN 1 /* Object partially overlaps query region */
11190#define FULLY_WITHIN 2 /* Object fully contained within query region */
11191
11192
11193#ifdef __cplusplus
11194} /* end of the 'extern "C"' block */
11195#endif
11196
11197#endif /* ifndef _SQLITE3RTREE_H_ */
11198
11199/******** End of sqlite3rtree.h *********/
11200/******** Begin file sqlite3session.h *********/
11201
11202#if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION)
11203#define __SQLITESESSION_H_ 1
11204
11205/*
11206** Make sure we can call this stuff from C++.
11207*/
11208#ifdef __cplusplus
11209extern "C" {
11210#endif
11211
11212
11213/*
11214** CAPI3REF: Session Object Handle
11215**
11216** An instance of this object is a [session] that can be used to
11217** record changes to a database.
11218*/
11219typedef struct sqlite3_session sqlite3_session;
11220
11221/*
11222** CAPI3REF: Changeset Iterator Handle
11223**
11224** An instance of this object acts as a cursor for iterating
11225** over the elements of a [changeset] or [patchset].
11226*/
11227typedef struct sqlite3_changeset_iter sqlite3_changeset_iter;
11228
11229/*
11230** CAPI3REF: Create A New Session Object
11231** CONSTRUCTOR: sqlite3_session
11232**
11233** Create a new session object attached to database handle db. If successful,
11234** a pointer to the new object is written to *ppSession and SQLITE_OK is
11235** returned. If an error occurs, *ppSession is set to NULL and an SQLite
11236** error code (e.g. SQLITE_NOMEM) is returned.
11237**
11238** It is possible to create multiple session objects attached to a single
11239** database handle.
11240**
11241** Session objects created using this function should be deleted using the
11242** [sqlite3session_delete()] function before the database handle that they
11243** are attached to is itself closed. If the database handle is closed before
11244** the session object is deleted, then the results of calling any session
11245** module function, including [sqlite3session_delete()] on the session object
11246** are undefined.
11247**
11248** Because the session module uses the [sqlite3_preupdate_hook()] API, it
11249** is not possible for an application to register a pre-update hook on a
11250** database handle that has one or more session objects attached. Nor is
11251** it possible to create a session object attached to a database handle for
11252** which a pre-update hook is already defined. The results of attempting
11253** either of these things are undefined.
11254**
11255** The session object will be used to create changesets for tables in
11256** database zDb, where zDb is either "main", or "temp", or the name of an
11257** attached database. It is not an error if database zDb is not attached
11258** to the database when the session object is created.
11259*/
11260SQLITE_API int sqlite3session_create(
11261 sqlite3 *db, /* Database handle */
11262 const char *zDb, /* Name of db (e.g. "main") */
11263 sqlite3_session **ppSession /* OUT: New session object */
11264);
11265
11266/*
11267** CAPI3REF: Delete A Session Object
11268** DESTRUCTOR: sqlite3_session
11269**
11270** Delete a session object previously allocated using
11271** [sqlite3session_create()]. Once a session object has been deleted, the
11272** results of attempting to use pSession with any other session module
11273** function are undefined.
11274**
11275** Session objects must be deleted before the database handle to which they
11276** are attached is closed. Refer to the documentation for
11277** [sqlite3session_create()] for details.
11278*/
11279SQLITE_API void sqlite3session_delete(sqlite3_session *pSession);
11280
11281/*
11282** CAPI3REF: Configure a Session Object
11283** METHOD: sqlite3_session
11284**
11285** This method is used to configure a session object after it has been
11286** created. At present the only valid values for the second parameter are
11287** [SQLITE_SESSION_OBJCONFIG_SIZE] and [SQLITE_SESSION_OBJCONFIG_ROWID].
11288**
11289*/
11290SQLITE_API int sqlite3session_object_config(sqlite3_session*, int op, void *pArg);
11291
11292/*
11293** CAPI3REF: Options for sqlite3session_object_config
11294**
11295** The following values may passed as the the 2nd parameter to
11296** sqlite3session_object_config().
11297**
11298** <dt>SQLITE_SESSION_OBJCONFIG_SIZE <dd>
11299** This option is used to set, clear or query the flag that enables
11300** the [sqlite3session_changeset_size()] API. Because it imposes some
11301** computational overhead, this API is disabled by default. Argument
11302** pArg must point to a value of type (int). If the value is initially
11303** 0, then the sqlite3session_changeset_size() API is disabled. If it
11304** is greater than 0, then the same API is enabled. Or, if the initial
11305** value is less than zero, no change is made. In all cases the (int)
11306** variable is set to 1 if the sqlite3session_changeset_size() API is
11307** enabled following the current call, or 0 otherwise.
11308**
11309** It is an error (SQLITE_MISUSE) to attempt to modify this setting after
11310** the first table has been attached to the session object.
11311**
11312** <dt>SQLITE_SESSION_OBJCONFIG_ROWID <dd>
11313** This option is used to set, clear or query the flag that enables
11314** collection of data for tables with no explicit PRIMARY KEY.
11315**
11316** Normally, tables with no explicit PRIMARY KEY are simply ignored
11317** by the sessions module. However, if this flag is set, it behaves
11318** as if such tables have a column "_rowid_ INTEGER PRIMARY KEY" inserted
11319** as their leftmost columns.
11320**
11321** It is an error (SQLITE_MISUSE) to attempt to modify this setting after
11322** the first table has been attached to the session object.
11323*/
11324#define SQLITE_SESSION_OBJCONFIG_SIZE 1
11325#define SQLITE_SESSION_OBJCONFIG_ROWID 2
11326
11327/*
11328** CAPI3REF: Enable Or Disable A Session Object
11329** METHOD: sqlite3_session
11330**
11331** Enable or disable the recording of changes by a session object. When
11332** enabled, a session object records changes made to the database. When
11333** disabled - it does not. A newly created session object is enabled.
11334** Refer to the documentation for [sqlite3session_changeset()] for further
11335** details regarding how enabling and disabling a session object affects
11336** the eventual changesets.
11337**
11338** Passing zero to this function disables the session. Passing a value
11339** greater than zero enables it. Passing a value less than zero is a
11340** no-op, and may be used to query the current state of the session.
11341**
11342** The return value indicates the final state of the session object: 0 if
11343** the session is disabled, or 1 if it is enabled.
11344*/
11345SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable);
11346
11347/*
11348** CAPI3REF: Set Or Clear the Indirect Change Flag
11349** METHOD: sqlite3_session
11350**
11351** Each change recorded by a session object is marked as either direct or
11352** indirect. A change is marked as indirect if either:
11353**
11354** <ul>
11355** <li> The session object "indirect" flag is set when the change is
11356** made, or
11357** <li> The change is made by an SQL trigger or foreign key action
11358** instead of directly as a result of a users SQL statement.
11359** </ul>
11360**
11361** If a single row is affected by more than one operation within a session,
11362** then the change is considered indirect if all operations meet the criteria
11363** for an indirect change above, or direct otherwise.
11364**
11365** This function is used to set, clear or query the session object indirect
11366** flag. If the second argument passed to this function is zero, then the
11367** indirect flag is cleared. If it is greater than zero, the indirect flag
11368** is set. Passing a value less than zero does not modify the current value
11369** of the indirect flag, and may be used to query the current state of the
11370** indirect flag for the specified session object.
11371**
11372** The return value indicates the final state of the indirect flag: 0 if
11373** it is clear, or 1 if it is set.
11374*/
11375SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect);
11376
11377/*
11378** CAPI3REF: Attach A Table To A Session Object
11379** METHOD: sqlite3_session
11380**
11381** If argument zTab is not NULL, then it is the name of a table to attach
11382** to the session object passed as the first argument. All subsequent changes
11383** made to the table while the session object is enabled will be recorded. See
11384** documentation for [sqlite3session_changeset()] for further details.
11385**
11386** Or, if argument zTab is NULL, then changes are recorded for all tables
11387** in the database. If additional tables are added to the database (by
11388** executing "CREATE TABLE" statements) after this call is made, changes for
11389** the new tables are also recorded.
11390**
11391** Changes can only be recorded for tables that have a PRIMARY KEY explicitly
11392** defined as part of their CREATE TABLE statement. It does not matter if the
11393** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY
11394** KEY may consist of a single column, or may be a composite key.
11395**
11396** It is not an error if the named table does not exist in the database. Nor
11397** is it an error if the named table does not have a PRIMARY KEY. However,
11398** no changes will be recorded in either of these scenarios.
11399**
11400** Changes are not recorded for individual rows that have NULL values stored
11401** in one or more of their PRIMARY KEY columns.
11402**
11403** SQLITE_OK is returned if the call completes without error. Or, if an error
11404** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned.
11405**
11406** <h3>Special sqlite_stat1 Handling</h3>
11407**
11408** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to
11409** some of the rules above. In SQLite, the schema of sqlite_stat1 is:
11410** <pre>
11411** CREATE TABLE sqlite_stat1(tbl,idx,stat)
11412** </pre>
11413**
11414** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are
11415** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes
11416** are recorded for rows for which (idx IS NULL) is true. However, for such
11417** rows a zero-length blob (SQL value X'') is stored in the changeset or
11418** patchset instead of a NULL value. This allows such changesets to be
11419** manipulated by legacy implementations of sqlite3changeset_invert(),
11420** concat() and similar.
11421**
11422** The sqlite3changeset_apply() function automatically converts the
11423** zero-length blob back to a NULL value when updating the sqlite_stat1
11424** table. However, if the application calls sqlite3changeset_new(),
11425** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset
11426** iterator directly (including on a changeset iterator passed to a
11427** conflict-handler callback) then the X'' value is returned. The application
11428** must translate X'' to NULL itself if required.
11429**
11430** Legacy (older than 3.22.0) versions of the sessions module cannot capture
11431** changes made to the sqlite_stat1 table. Legacy versions of the
11432** sqlite3changeset_apply() function silently ignore any modifications to the
11433** sqlite_stat1 table that are part of a changeset or patchset.
11434*/
11435SQLITE_API int sqlite3session_attach(
11436 sqlite3_session *pSession, /* Session object */
11437 const char *zTab /* Table name */
11438);
11439
11440/*
11441** CAPI3REF: Set a table filter on a Session Object.
11442** METHOD: sqlite3_session
11443**
11444** The second argument (xFilter) is the "filter callback". For changes to rows
11445** in tables that are not attached to the Session object, the filter is called
11446** to determine whether changes to the table's rows should be tracked or not.
11447** If xFilter returns 0, changes are not tracked. Note that once a table is
11448** attached, xFilter will not be called again.
11449*/
11450SQLITE_API void sqlite3session_table_filter(
11451 sqlite3_session *pSession, /* Session object */
11452 int(*xFilter)(
11453 void *pCtx, /* Copy of third arg to _filter_table() */
11454 const char *zTab /* Table name */
11455 ),
11456 void *pCtx /* First argument passed to xFilter */
11457);
11458
11459/*
11460** CAPI3REF: Generate A Changeset From A Session Object
11461** METHOD: sqlite3_session
11462**
11463** Obtain a changeset containing changes to the tables attached to the
11464** session object passed as the first argument. If successful,
11465** set *ppChangeset to point to a buffer containing the changeset
11466** and *pnChangeset to the size of the changeset in bytes before returning
11467** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to
11468** zero and return an SQLite error code.
11469**
11470** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes,
11471** each representing a change to a single row of an attached table. An INSERT
11472** change contains the values of each field of a new database row. A DELETE
11473** contains the original values of each field of a deleted database row. An
11474** UPDATE change contains the original values of each field of an updated
11475** database row along with the updated values for each updated non-primary-key
11476** column. It is not possible for an UPDATE change to represent a change that
11477** modifies the values of primary key columns. If such a change is made, it
11478** is represented in a changeset as a DELETE followed by an INSERT.
11479**
11480** Changes are not recorded for rows that have NULL values stored in one or
11481** more of their PRIMARY KEY columns. If such a row is inserted or deleted,
11482** no corresponding change is present in the changesets returned by this
11483** function. If an existing row with one or more NULL values stored in
11484** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL,
11485** only an INSERT is appears in the changeset. Similarly, if an existing row
11486** with non-NULL PRIMARY KEY values is updated so that one or more of its
11487** PRIMARY KEY columns are set to NULL, the resulting changeset contains a
11488** DELETE change only.
11489**
11490** The contents of a changeset may be traversed using an iterator created
11491** using the [sqlite3changeset_start()] API. A changeset may be applied to
11492** a database with a compatible schema using the [sqlite3changeset_apply()]
11493** API.
11494**
11495** Within a changeset generated by this function, all changes related to a
11496** single table are grouped together. In other words, when iterating through
11497** a changeset or when applying a changeset to a database, all changes related
11498** to a single table are processed before moving on to the next table. Tables
11499** are sorted in the same order in which they were attached (or auto-attached)
11500** to the sqlite3_session object. The order in which the changes related to
11501** a single table are stored is undefined.
11502**
11503** Following a successful call to this function, it is the responsibility of
11504** the caller to eventually free the buffer that *ppChangeset points to using
11505** [sqlite3_free()].
11506**
11507** <h3>Changeset Generation</h3>
11508**
11509** Once a table has been attached to a session object, the session object
11510** records the primary key values of all new rows inserted into the table.
11511** It also records the original primary key and other column values of any
11512** deleted or updated rows. For each unique primary key value, data is only
11513** recorded once - the first time a row with said primary key is inserted,
11514** updated or deleted in the lifetime of the session.
11515**
11516** There is one exception to the previous paragraph: when a row is inserted,
11517** updated or deleted, if one or more of its primary key columns contain a
11518** NULL value, no record of the change is made.
11519**
11520** The session object therefore accumulates two types of records - those
11521** that consist of primary key values only (created when the user inserts
11522** a new record) and those that consist of the primary key values and the
11523** original values of other table columns (created when the users deletes
11524** or updates a record).
11525**
11526** When this function is called, the requested changeset is created using
11527** both the accumulated records and the current contents of the database
11528** file. Specifically:
11529**
11530** <ul>
11531** <li> For each record generated by an insert, the database is queried
11532** for a row with a matching primary key. If one is found, an INSERT
11533** change is added to the changeset. If no such row is found, no change
11534** is added to the changeset.
11535**
11536** <li> For each record generated by an update or delete, the database is
11537** queried for a row with a matching primary key. If such a row is
11538** found and one or more of the non-primary key fields have been
11539** modified from their original values, an UPDATE change is added to
11540** the changeset. Or, if no such row is found in the table, a DELETE
11541** change is added to the changeset. If there is a row with a matching
11542** primary key in the database, but all fields contain their original
11543** values, no change is added to the changeset.
11544** </ul>
11545**
11546** This means, amongst other things, that if a row is inserted and then later
11547** deleted while a session object is active, neither the insert nor the delete
11548** will be present in the changeset. Or if a row is deleted and then later a
11549** row with the same primary key values inserted while a session object is
11550** active, the resulting changeset will contain an UPDATE change instead of
11551** a DELETE and an INSERT.
11552**
11553** When a session object is disabled (see the [sqlite3session_enable()] API),
11554** it does not accumulate records when rows are inserted, updated or deleted.
11555** This may appear to have some counter-intuitive effects if a single row
11556** is written to more than once during a session. For example, if a row
11557** is inserted while a session object is enabled, then later deleted while
11558** the same session object is disabled, no INSERT record will appear in the
11559** changeset, even though the delete took place while the session was disabled.
11560** Or, if one field of a row is updated while a session is enabled, and
11561** then another field of the same row is updated while the session is disabled,
11562** the resulting changeset will contain an UPDATE change that updates both
11563** fields.
11564*/
11565SQLITE_API int sqlite3session_changeset(
11566 sqlite3_session *pSession, /* Session object */
11567 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */
11568 void **ppChangeset /* OUT: Buffer containing changeset */
11569);
11570
11571/*
11572** CAPI3REF: Return An Upper-limit For The Size Of The Changeset
11573** METHOD: sqlite3_session
11574**
11575** By default, this function always returns 0. For it to return
11576** a useful result, the sqlite3_session object must have been configured
11577** to enable this API using sqlite3session_object_config() with the
11578** SQLITE_SESSION_OBJCONFIG_SIZE verb.
11579**
11580** When enabled, this function returns an upper limit, in bytes, for the size
11581** of the changeset that might be produced if sqlite3session_changeset() were
11582** called. The final changeset size might be equal to or smaller than the
11583** size in bytes returned by this function.
11584*/
11585SQLITE_API sqlite3_int64 sqlite3session_changeset_size(sqlite3_session *pSession);
11586
11587/*
11588** CAPI3REF: Load The Difference Between Tables Into A Session
11589** METHOD: sqlite3_session
11590**
11591** If it is not already attached to the session object passed as the first
11592** argument, this function attaches table zTbl in the same manner as the
11593** [sqlite3session_attach()] function. If zTbl does not exist, or if it
11594** does not have a primary key, this function is a no-op (but does not return
11595** an error).
11596**
11597** Argument zFromDb must be the name of a database ("main", "temp" etc.)
11598** attached to the same database handle as the session object that contains
11599** a table compatible with the table attached to the session by this function.
11600** A table is considered compatible if it:
11601**
11602** <ul>
11603** <li> Has the same name,
11604** <li> Has the same set of columns declared in the same order, and
11605** <li> Has the same PRIMARY KEY definition.
11606** </ul>
11607**
11608** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables
11609** are compatible but do not have any PRIMARY KEY columns, it is not an error
11610** but no changes are added to the session object. As with other session
11611** APIs, tables without PRIMARY KEYs are simply ignored.
11612**
11613** This function adds a set of changes to the session object that could be
11614** used to update the table in database zFrom (call this the "from-table")
11615** so that its content is the same as the table attached to the session
11616** object (call this the "to-table"). Specifically:
11617**
11618** <ul>
11619** <li> For each row (primary key) that exists in the to-table but not in
11620** the from-table, an INSERT record is added to the session object.
11621**
11622** <li> For each row (primary key) that exists in the to-table but not in
11623** the from-table, a DELETE record is added to the session object.
11624**
11625** <li> For each row (primary key) that exists in both tables, but features
11626** different non-PK values in each, an UPDATE record is added to the
11627** session.
11628** </ul>
11629**
11630** To clarify, if this function is called and then a changeset constructed
11631** using [sqlite3session_changeset()], then after applying that changeset to
11632** database zFrom the contents of the two compatible tables would be
11633** identical.
11634**
11635** Unless the call to this function is a no-op as described above, it is an
11636** error if database zFrom does not exist or does not contain the required
11637** compatible table.
11638**
11639** If the operation is successful, SQLITE_OK is returned. Otherwise, an SQLite
11640** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg
11641** may be set to point to a buffer containing an English language error
11642** message. It is the responsibility of the caller to free this buffer using
11643** sqlite3_free().
11644*/
11645SQLITE_API int sqlite3session_diff(
11646 sqlite3_session *pSession,
11647 const char *zFromDb,
11648 const char *zTbl,
11649 char **pzErrMsg
11650);
11651
11652
11653/*
11654** CAPI3REF: Generate A Patchset From A Session Object
11655** METHOD: sqlite3_session
11656**
11657** The differences between a patchset and a changeset are that:
11658**
11659** <ul>
11660** <li> DELETE records consist of the primary key fields only. The
11661** original values of other fields are omitted.
11662** <li> The original values of any modified fields are omitted from
11663** UPDATE records.
11664** </ul>
11665**
11666** A patchset blob may be used with up to date versions of all
11667** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(),
11668** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly,
11669** attempting to use a patchset blob with old versions of the
11670** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error.
11671**
11672** Because the non-primary key "old.*" fields are omitted, no
11673** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset
11674** is passed to the sqlite3changeset_apply() API. Other conflict types work
11675** in the same way as for changesets.
11676**
11677** Changes within a patchset are ordered in the same way as for changesets
11678** generated by the sqlite3session_changeset() function (i.e. all changes for
11679** a single table are grouped together, tables appear in the order in which
11680** they were attached to the session object).
11681*/
11682SQLITE_API int sqlite3session_patchset(
11683 sqlite3_session *pSession, /* Session object */
11684 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */
11685 void **ppPatchset /* OUT: Buffer containing patchset */
11686);
11687
11688/*
11689** CAPI3REF: Test if a changeset has recorded any changes.
11690**
11691** Return non-zero if no changes to attached tables have been recorded by
11692** the session object passed as the first argument. Otherwise, if one or
11693** more changes have been recorded, return zero.
11694**
11695** Even if this function returns zero, it is possible that calling
11696** [sqlite3session_changeset()] on the session handle may still return a
11697** changeset that contains no changes. This can happen when a row in
11698** an attached table is modified and then later on the original values
11699** are restored. However, if this function returns non-zero, then it is
11700** guaranteed that a call to sqlite3session_changeset() will return a
11701** changeset containing zero changes.
11702*/
11703SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession);
11704
11705/*
11706** CAPI3REF: Query for the amount of heap memory used by a session object.
11707**
11708** This API returns the total amount of heap memory in bytes currently
11709** used by the session object passed as the only argument.
11710*/
11711SQLITE_API sqlite3_int64 sqlite3session_memory_used(sqlite3_session *pSession);
11712
11713/*
11714** CAPI3REF: Create An Iterator To Traverse A Changeset
11715** CONSTRUCTOR: sqlite3_changeset_iter
11716**
11717** Create an iterator used to iterate through the contents of a changeset.
11718** If successful, *pp is set to point to the iterator handle and SQLITE_OK
11719** is returned. Otherwise, if an error occurs, *pp is set to zero and an
11720** SQLite error code is returned.
11721**
11722** The following functions can be used to advance and query a changeset
11723** iterator created by this function:
11724**
11725** <ul>
11726** <li> [sqlite3changeset_next()]
11727** <li> [sqlite3changeset_op()]
11728** <li> [sqlite3changeset_new()]
11729** <li> [sqlite3changeset_old()]
11730** </ul>
11731**
11732** It is the responsibility of the caller to eventually destroy the iterator
11733** by passing it to [sqlite3changeset_finalize()]. The buffer containing the
11734** changeset (pChangeset) must remain valid until after the iterator is
11735** destroyed.
11736**
11737** Assuming the changeset blob was created by one of the
11738** [sqlite3session_changeset()], [sqlite3changeset_concat()] or
11739** [sqlite3changeset_invert()] functions, all changes within the changeset
11740** that apply to a single table are grouped together. This means that when
11741** an application iterates through a changeset using an iterator created by
11742** this function, all changes that relate to a single table are visited
11743** consecutively. There is no chance that the iterator will visit a change
11744** the applies to table X, then one for table Y, and then later on visit
11745** another change for table X.
11746**
11747** The behavior of sqlite3changeset_start_v2() and its streaming equivalent
11748** may be modified by passing a combination of
11749** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter.
11750**
11751** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b>
11752** and therefore subject to change.
11753*/
11754SQLITE_API int sqlite3changeset_start(
11755 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
11756 int nChangeset, /* Size of changeset blob in bytes */
11757 void *pChangeset /* Pointer to blob containing changeset */
11758);
11759SQLITE_API int sqlite3changeset_start_v2(
11760 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
11761 int nChangeset, /* Size of changeset blob in bytes */
11762 void *pChangeset, /* Pointer to blob containing changeset */
11763 int flags /* SESSION_CHANGESETSTART_* flags */
11764);
11765
11766/*
11767** CAPI3REF: Flags for sqlite3changeset_start_v2
11768**
11769** The following flags may passed via the 4th parameter to
11770** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]:
11771**
11772** <dt>SQLITE_CHANGESETSTART_INVERT <dd>
11773** Invert the changeset while iterating through it. This is equivalent to
11774** inverting a changeset using sqlite3changeset_invert() before applying it.
11775** It is an error to specify this flag with a patchset.
11776*/
11777#define SQLITE_CHANGESETSTART_INVERT 0x0002
11778
11779
11780/*
11781** CAPI3REF: Advance A Changeset Iterator
11782** METHOD: sqlite3_changeset_iter
11783**
11784** This function may only be used with iterators created by the function
11785** [sqlite3changeset_start()]. If it is called on an iterator passed to
11786** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE
11787** is returned and the call has no effect.
11788**
11789** Immediately after an iterator is created by sqlite3changeset_start(), it
11790** does not point to any change in the changeset. Assuming the changeset
11791** is not empty, the first call to this function advances the iterator to
11792** point to the first change in the changeset. Each subsequent call advances
11793** the iterator to point to the next change in the changeset (if any). If
11794** no error occurs and the iterator points to a valid change after a call
11795** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned.
11796** Otherwise, if all changes in the changeset have already been visited,
11797** SQLITE_DONE is returned.
11798**
11799** If an error occurs, an SQLite error code is returned. Possible error
11800** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or
11801** SQLITE_NOMEM.
11802*/
11803SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter);
11804
11805/*
11806** CAPI3REF: Obtain The Current Operation From A Changeset Iterator
11807** METHOD: sqlite3_changeset_iter
11808**
11809** The pIter argument passed to this function may either be an iterator
11810** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
11811** created by [sqlite3changeset_start()]. In the latter case, the most recent
11812** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this
11813** is not the case, this function returns [SQLITE_MISUSE].
11814**
11815** Arguments pOp, pnCol and pzTab may not be NULL. Upon return, three
11816** outputs are set through these pointers:
11817**
11818** *pOp is set to one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE],
11819** depending on the type of change that the iterator currently points to;
11820**
11821** *pnCol is set to the number of columns in the table affected by the change; and
11822**
11823** *pzTab is set to point to a nul-terminated utf-8 encoded string containing
11824** the name of the table affected by the current change. The buffer remains
11825** valid until either sqlite3changeset_next() is called on the iterator
11826** or until the conflict-handler function returns.
11827**
11828** If pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change
11829** is an indirect change, or false (0) otherwise. See the documentation for
11830** [sqlite3session_indirect()] for a description of direct and indirect
11831** changes.
11832**
11833** If no error occurs, SQLITE_OK is returned. If an error does occur, an
11834** SQLite error code is returned. The values of the output variables may not
11835** be trusted in this case.
11836*/
11837SQLITE_API int sqlite3changeset_op(
11838 sqlite3_changeset_iter *pIter, /* Iterator object */
11839 const char **pzTab, /* OUT: Pointer to table name */
11840 int *pnCol, /* OUT: Number of columns in table */
11841 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */
11842 int *pbIndirect /* OUT: True for an 'indirect' change */
11843);
11844
11845/*
11846** CAPI3REF: Obtain The Primary Key Definition Of A Table
11847** METHOD: sqlite3_changeset_iter
11848**
11849** For each modified table, a changeset includes the following:
11850**
11851** <ul>
11852** <li> The number of columns in the table, and
11853** <li> Which of those columns make up the tables PRIMARY KEY.
11854** </ul>
11855**
11856** This function is used to find which columns comprise the PRIMARY KEY of
11857** the table modified by the change that iterator pIter currently points to.
11858** If successful, *pabPK is set to point to an array of nCol entries, where
11859** nCol is the number of columns in the table. Elements of *pabPK are set to
11860** 0x01 if the corresponding column is part of the tables primary key, or
11861** 0x00 if it is not.
11862**
11863** If argument pnCol is not NULL, then *pnCol is set to the number of columns
11864** in the table.
11865**
11866** If this function is called when the iterator does not point to a valid
11867** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise,
11868** SQLITE_OK is returned and the output variables populated as described
11869** above.
11870*/
11871SQLITE_API int sqlite3changeset_pk(
11872 sqlite3_changeset_iter *pIter, /* Iterator object */
11873 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */
11874 int *pnCol /* OUT: Number of entries in output array */
11875);
11876
11877/*
11878** CAPI3REF: Obtain old.* Values From A Changeset Iterator
11879** METHOD: sqlite3_changeset_iter
11880**
11881** The pIter argument passed to this function may either be an iterator
11882** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
11883** created by [sqlite3changeset_start()]. In the latter case, the most recent
11884** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
11885** Furthermore, it may only be called if the type of change that the iterator
11886** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise,
11887** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
11888**
11889** Argument iVal must be greater than or equal to 0, and less than the number
11890** of columns in the table affected by the current change. Otherwise,
11891** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
11892**
11893** If successful, this function sets *ppValue to point to a protected
11894** sqlite3_value object containing the iVal'th value from the vector of
11895** original row values stored as part of the UPDATE or DELETE change and
11896** returns SQLITE_OK. The name of the function comes from the fact that this
11897** is similar to the "old.*" columns available to update or delete triggers.
11898**
11899** If some other error occurs (e.g. an OOM condition), an SQLite error code
11900** is returned and *ppValue is set to NULL.
11901*/
11902SQLITE_API int sqlite3changeset_old(
11903 sqlite3_changeset_iter *pIter, /* Changeset iterator */
11904 int iVal, /* Column number */
11905 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */
11906);
11907
11908/*
11909** CAPI3REF: Obtain new.* Values From A Changeset Iterator
11910** METHOD: sqlite3_changeset_iter
11911**
11912** The pIter argument passed to this function may either be an iterator
11913** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
11914** created by [sqlite3changeset_start()]. In the latter case, the most recent
11915** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
11916** Furthermore, it may only be called if the type of change that the iterator
11917** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise,
11918** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
11919**
11920** Argument iVal must be greater than or equal to 0, and less than the number
11921** of columns in the table affected by the current change. Otherwise,
11922** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
11923**
11924** If successful, this function sets *ppValue to point to a protected
11925** sqlite3_value object containing the iVal'th value from the vector of
11926** new row values stored as part of the UPDATE or INSERT change and
11927** returns SQLITE_OK. If the change is an UPDATE and does not include
11928** a new value for the requested column, *ppValue is set to NULL and
11929** SQLITE_OK returned. The name of the function comes from the fact that
11930** this is similar to the "new.*" columns available to update or delete
11931** triggers.
11932**
11933** If some other error occurs (e.g. an OOM condition), an SQLite error code
11934** is returned and *ppValue is set to NULL.
11935*/
11936SQLITE_API int sqlite3changeset_new(
11937 sqlite3_changeset_iter *pIter, /* Changeset iterator */
11938 int iVal, /* Column number */
11939 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */
11940);
11941
11942/*
11943** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator
11944** METHOD: sqlite3_changeset_iter
11945**
11946** This function should only be used with iterator objects passed to a
11947** conflict-handler callback by [sqlite3changeset_apply()] with either
11948** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function
11949** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue
11950** is set to NULL.
11951**
11952** Argument iVal must be greater than or equal to 0, and less than the number
11953** of columns in the table affected by the current change. Otherwise,
11954** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
11955**
11956** If successful, this function sets *ppValue to point to a protected
11957** sqlite3_value object containing the iVal'th value from the
11958** "conflicting row" associated with the current conflict-handler callback
11959** and returns SQLITE_OK.
11960**
11961** If some other error occurs (e.g. an OOM condition), an SQLite error code
11962** is returned and *ppValue is set to NULL.
11963*/
11964SQLITE_API int sqlite3changeset_conflict(
11965 sqlite3_changeset_iter *pIter, /* Changeset iterator */
11966 int iVal, /* Column number */
11967 sqlite3_value **ppValue /* OUT: Value from conflicting row */
11968);
11969
11970/*
11971** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations
11972** METHOD: sqlite3_changeset_iter
11973**
11974** This function may only be called with an iterator passed to an
11975** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case
11976** it sets the output variable to the total number of known foreign key
11977** violations in the destination database and returns SQLITE_OK.
11978**
11979** In all other cases this function returns SQLITE_MISUSE.
11980*/
11981SQLITE_API int sqlite3changeset_fk_conflicts(
11982 sqlite3_changeset_iter *pIter, /* Changeset iterator */
11983 int *pnOut /* OUT: Number of FK violations */
11984);
11985
11986
11987/*
11988** CAPI3REF: Finalize A Changeset Iterator
11989** METHOD: sqlite3_changeset_iter
11990**
11991** This function is used to finalize an iterator allocated with
11992** [sqlite3changeset_start()].
11993**
11994** This function should only be called on iterators created using the
11995** [sqlite3changeset_start()] function. If an application calls this
11996** function with an iterator passed to a conflict-handler by
11997** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the
11998** call has no effect.
11999**
12000** If an error was encountered within a call to an sqlite3changeset_xxx()
12001** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an
12002** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding
12003** to that error is returned by this function. Otherwise, SQLITE_OK is
12004** returned. This is to allow the following pattern (pseudo-code):
12005**
12006** <pre>
12007** sqlite3changeset_start();
12008** while( SQLITE_ROW==sqlite3changeset_next() ){
12009** // Do something with change.
12010** }
12011** rc = sqlite3changeset_finalize();
12012** if( rc!=SQLITE_OK ){
12013** // An error has occurred
12014** }
12015** </pre>
12016*/
12017SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter);
12018
12019/*
12020** CAPI3REF: Invert A Changeset
12021**
12022** This function is used to "invert" a changeset object. Applying an inverted
12023** changeset to a database reverses the effects of applying the uninverted
12024** changeset. Specifically:
12025**
12026** <ul>
12027** <li> Each DELETE change is changed to an INSERT, and
12028** <li> Each INSERT change is changed to a DELETE, and
12029** <li> For each UPDATE change, the old.* and new.* values are exchanged.
12030** </ul>
12031**
12032** This function does not change the order in which changes appear within
12033** the changeset. It merely reverses the sense of each individual change.
12034**
12035** If successful, a pointer to a buffer containing the inverted changeset
12036** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and
12037** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are
12038** zeroed and an SQLite error code returned.
12039**
12040** It is the responsibility of the caller to eventually call sqlite3_free()
12041** on the *ppOut pointer to free the buffer allocation following a successful
12042** call to this function.
12043**
12044** WARNING/TODO: This function currently assumes that the input is a valid
12045** changeset. If it is not, the results are undefined.
12046*/
12047SQLITE_API int sqlite3changeset_invert(
12048 int nIn, const void *pIn, /* Input changeset */
12049 int *pnOut, void **ppOut /* OUT: Inverse of input */
12050);
12051
12052/*
12053** CAPI3REF: Concatenate Two Changeset Objects
12054**
12055** This function is used to concatenate two changesets, A and B, into a
12056** single changeset. The result is a changeset equivalent to applying
12057** changeset A followed by changeset B.
12058**
12059** This function combines the two input changesets using an
12060** sqlite3_changegroup object. Calling it produces similar results as the
12061** following code fragment:
12062**
12063** <pre>
12064** sqlite3_changegroup *pGrp;
12065** rc = sqlite3_changegroup_new(&pGrp);
12066** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA);
12067** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB);
12068** if( rc==SQLITE_OK ){
12069** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut);
12070** }else{
12071** *ppOut = 0;
12072** *pnOut = 0;
12073** }
12074** </pre>
12075**
12076** Refer to the sqlite3_changegroup documentation below for details.
12077*/
12078SQLITE_API int sqlite3changeset_concat(
12079 int nA, /* Number of bytes in buffer pA */
12080 void *pA, /* Pointer to buffer containing changeset A */
12081 int nB, /* Number of bytes in buffer pB */
12082 void *pB, /* Pointer to buffer containing changeset B */
12083 int *pnOut, /* OUT: Number of bytes in output changeset */
12084 void **ppOut /* OUT: Buffer containing output changeset */
12085);
12086
12087/*
12088** CAPI3REF: Changegroup Handle
12089**
12090** A changegroup is an object used to combine two or more
12091** [changesets] or [patchsets]
12092*/
12093typedef struct sqlite3_changegroup sqlite3_changegroup;
12094
12095/*
12096** CAPI3REF: Create A New Changegroup Object
12097** CONSTRUCTOR: sqlite3_changegroup
12098**
12099** An sqlite3_changegroup object is used to combine two or more changesets
12100** (or patchsets) into a single changeset (or patchset). A single changegroup
12101** object may combine changesets or patchsets, but not both. The output is
12102** always in the same format as the input.
12103**
12104** If successful, this function returns SQLITE_OK and populates (*pp) with
12105** a pointer to a new sqlite3_changegroup object before returning. The caller
12106** should eventually free the returned object using a call to
12107** sqlite3changegroup_delete(). If an error occurs, an SQLite error code
12108** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL.
12109**
12110** The usual usage pattern for an sqlite3_changegroup object is as follows:
12111**
12112** <ul>
12113** <li> It is created using a call to sqlite3changegroup_new().
12114**
12115** <li> Zero or more changesets (or patchsets) are added to the object
12116** by calling sqlite3changegroup_add().
12117**
12118** <li> The result of combining all input changesets together is obtained
12119** by the application via a call to sqlite3changegroup_output().
12120**
12121** <li> The object is deleted using a call to sqlite3changegroup_delete().
12122** </ul>
12123**
12124** Any number of calls to add() and output() may be made between the calls to
12125** new() and delete(), and in any order.
12126**
12127** As well as the regular sqlite3changegroup_add() and
12128** sqlite3changegroup_output() functions, also available are the streaming
12129** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm().
12130*/
12131SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp);
12132
12133/*
12134** CAPI3REF: Add a Schema to a Changegroup
12135** METHOD: sqlite3_changegroup_schema
12136**
12137** This method may be used to optionally enforce the rule that the changesets
12138** added to the changegroup handle must match the schema of database zDb
12139** ("main", "temp", or the name of an attached database). If
12140** sqlite3changegroup_add() is called to add a changeset that is not compatible
12141** with the configured schema, SQLITE_SCHEMA is returned and the changegroup
12142** object is left in an undefined state.
12143**
12144** A changeset schema is considered compatible with the database schema in
12145** the same way as for sqlite3changeset_apply(). Specifically, for each
12146** table in the changeset, there exists a database table with:
12147**
12148** <ul>
12149** <li> The name identified by the changeset, and
12150** <li> at least as many columns as recorded in the changeset, and
12151** <li> the primary key columns in the same position as recorded in
12152** the changeset.
12153** </ul>
12154**
12155** The output of the changegroup object always has the same schema as the
12156** database nominated using this function. In cases where changesets passed
12157** to sqlite3changegroup_add() have fewer columns than the corresponding table
12158** in the database schema, these are filled in using the default column
12159** values from the database schema. This makes it possible to combined
12160** changesets that have different numbers of columns for a single table
12161** within a changegroup, provided that they are otherwise compatible.
12162*/
12163SQLITE_API int sqlite3changegroup_schema(sqlite3_changegroup*, sqlite3*, const char *zDb);
12164
12165/*
12166** CAPI3REF: Add A Changeset To A Changegroup
12167** METHOD: sqlite3_changegroup
12168**
12169** Add all changes within the changeset (or patchset) in buffer pData (size
12170** nData bytes) to the changegroup.
12171**
12172** If the buffer contains a patchset, then all prior calls to this function
12173** on the same changegroup object must also have specified patchsets. Or, if
12174** the buffer contains a changeset, so must have the earlier calls to this
12175** function. Otherwise, SQLITE_ERROR is returned and no changes are added
12176** to the changegroup.
12177**
12178** Rows within the changeset and changegroup are identified by the values in
12179** their PRIMARY KEY columns. A change in the changeset is considered to
12180** apply to the same row as a change already present in the changegroup if
12181** the two rows have the same primary key.
12182**
12183** Changes to rows that do not already appear in the changegroup are
12184** simply copied into it. Or, if both the new changeset and the changegroup
12185** contain changes that apply to a single row, the final contents of the
12186** changegroup depends on the type of each change, as follows:
12187**
12188** <table border=1 style="margin-left:8ex;margin-right:8ex">
12189** <tr><th style="white-space:pre">Existing Change </th>
12190** <th style="white-space:pre">New Change </th>
12191** <th>Output Change
12192** <tr><td>INSERT <td>INSERT <td>
12193** The new change is ignored. This case does not occur if the new
12194** changeset was recorded immediately after the changesets already
12195** added to the changegroup.
12196** <tr><td>INSERT <td>UPDATE <td>
12197** The INSERT change remains in the changegroup. The values in the
12198** INSERT change are modified as if the row was inserted by the
12199** existing change and then updated according to the new change.
12200** <tr><td>INSERT <td>DELETE <td>
12201** The existing INSERT is removed from the changegroup. The DELETE is
12202** not added.
12203** <tr><td>UPDATE <td>INSERT <td>
12204** The new change is ignored. This case does not occur if the new
12205** changeset was recorded immediately after the changesets already
12206** added to the changegroup.
12207** <tr><td>UPDATE <td>UPDATE <td>
12208** The existing UPDATE remains within the changegroup. It is amended
12209** so that the accompanying values are as if the row was updated once
12210** by the existing change and then again by the new change.
12211** <tr><td>UPDATE <td>DELETE <td>
12212** The existing UPDATE is replaced by the new DELETE within the
12213** changegroup.
12214** <tr><td>DELETE <td>INSERT <td>
12215** If one or more of the column values in the row inserted by the
12216** new change differ from those in the row deleted by the existing
12217** change, the existing DELETE is replaced by an UPDATE within the
12218** changegroup. Otherwise, if the inserted row is exactly the same
12219** as the deleted row, the existing DELETE is simply discarded.
12220** <tr><td>DELETE <td>UPDATE <td>
12221** The new change is ignored. This case does not occur if the new
12222** changeset was recorded immediately after the changesets already
12223** added to the changegroup.
12224** <tr><td>DELETE <td>DELETE <td>
12225** The new change is ignored. This case does not occur if the new
12226** changeset was recorded immediately after the changesets already
12227** added to the changegroup.
12228** </table>
12229**
12230** If the new changeset contains changes to a table that is already present
12231** in the changegroup, then the number of columns and the position of the
12232** primary key columns for the table must be consistent. If this is not the
12233** case, this function fails with SQLITE_SCHEMA. Except, if the changegroup
12234** object has been configured with a database schema using the
12235** sqlite3changegroup_schema() API, then it is possible to combine changesets
12236** with different numbers of columns for a single table, provided that
12237** they are otherwise compatible.
12238**
12239** If the input changeset appears to be corrupt and the corruption is
12240** detected, SQLITE_CORRUPT is returned. Or, if an out-of-memory condition
12241** occurs during processing, this function returns SQLITE_NOMEM.
12242**
12243** In all cases, if an error occurs the state of the final contents of the
12244** changegroup is undefined. If no error occurs, SQLITE_OK is returned.
12245*/
12246SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData);
12247
12248/*
12249** CAPI3REF: Add A Single Change To A Changegroup
12250** METHOD: sqlite3_changegroup
12251**
12252** This function adds the single change currently indicated by the iterator
12253** passed as the second argument to the changegroup object. The rules for
12254** adding the change are just as described for [sqlite3changegroup_add()].
12255**
12256** If the change is successfully added to the changegroup, SQLITE_OK is
12257** returned. Otherwise, an SQLite error code is returned.
12258**
12259** The iterator must point to a valid entry when this function is called.
12260** If it does not, SQLITE_ERROR is returned and no change is added to the
12261** changegroup. Additionally, the iterator must not have been opened with
12262** the SQLITE_CHANGESETAPPLY_INVERT flag. In this case SQLITE_ERROR is also
12263** returned.
12264*/
12265SQLITE_API int sqlite3changegroup_add_change(
12266 sqlite3_changegroup*,
12267 sqlite3_changeset_iter*
12268);
12269
12270
12271
12272/*
12273** CAPI3REF: Obtain A Composite Changeset From A Changegroup
12274** METHOD: sqlite3_changegroup
12275**
12276** Obtain a buffer containing a changeset (or patchset) representing the
12277** current contents of the changegroup. If the inputs to the changegroup
12278** were themselves changesets, the output is a changeset. Or, if the
12279** inputs were patchsets, the output is also a patchset.
12280**
12281** As with the output of the sqlite3session_changeset() and
12282** sqlite3session_patchset() functions, all changes related to a single
12283** table are grouped together in the output of this function. Tables appear
12284** in the same order as for the very first changeset added to the changegroup.
12285** If the second or subsequent changesets added to the changegroup contain
12286** changes for tables that do not appear in the first changeset, they are
12287** appended onto the end of the output changeset, again in the order in
12288** which they are first encountered.
12289**
12290** If an error occurs, an SQLite error code is returned and the output
12291** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK
12292** is returned and the output variables are set to the size of and a
12293** pointer to the output buffer, respectively. In this case it is the
12294** responsibility of the caller to eventually free the buffer using a
12295** call to sqlite3_free().
12296*/
12297SQLITE_API int sqlite3changegroup_output(
12298 sqlite3_changegroup*,
12299 int *pnData, /* OUT: Size of output buffer in bytes */
12300 void **ppData /* OUT: Pointer to output buffer */
12301);
12302
12303/*
12304** CAPI3REF: Delete A Changegroup Object
12305** DESTRUCTOR: sqlite3_changegroup
12306*/
12307SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*);
12308
12309/*
12310** CAPI3REF: Apply A Changeset To A Database
12311**
12312** Apply a changeset or patchset to a database. These functions attempt to
12313** update the "main" database attached to handle db with the changes found in
12314** the changeset passed via the second and third arguments.
12315**
12316** The fourth argument (xFilter) passed to these functions is the "filter
12317** callback". If it is not NULL, then for each table affected by at least one
12318** change in the changeset, the filter callback is invoked with
12319** the table name as the second argument, and a copy of the context pointer
12320** passed as the sixth argument as the first. If the "filter callback"
12321** returns zero, then no attempt is made to apply any changes to the table.
12322** Otherwise, if the return value is non-zero or the xFilter argument to
12323** is NULL, all changes related to the table are attempted.
12324**
12325** For each table that is not excluded by the filter callback, this function
12326** tests that the target database contains a compatible table. A table is
12327** considered compatible if all of the following are true:
12328**
12329** <ul>
12330** <li> The table has the same name as the name recorded in the
12331** changeset, and
12332** <li> The table has at least as many columns as recorded in the
12333** changeset, and
12334** <li> The table has primary key columns in the same position as
12335** recorded in the changeset.
12336** </ul>
12337**
12338** If there is no compatible table, it is not an error, but none of the
12339** changes associated with the table are applied. A warning message is issued
12340** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most
12341** one such warning is issued for each table in the changeset.
12342**
12343** For each change for which there is a compatible table, an attempt is made
12344** to modify the table contents according to the UPDATE, INSERT or DELETE
12345** change. If a change cannot be applied cleanly, the conflict handler
12346** function passed as the fifth argument to sqlite3changeset_apply() may be
12347** invoked. A description of exactly when the conflict handler is invoked for
12348** each type of change is below.
12349**
12350** Unlike the xFilter argument, xConflict may not be passed NULL. The results
12351** of passing anything other than a valid function pointer as the xConflict
12352** argument are undefined.
12353**
12354** Each time the conflict handler function is invoked, it must return one
12355** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or
12356** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned
12357** if the second argument passed to the conflict handler is either
12358** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler
12359** returns an illegal value, any changes already made are rolled back and
12360** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different
12361** actions are taken by sqlite3changeset_apply() depending on the value
12362** returned by each invocation of the conflict-handler function. Refer to
12363** the documentation for the three
12364** [SQLITE_CHANGESET_OMIT|available return values] for details.
12365**
12366** <dl>
12367** <dt>DELETE Changes<dd>
12368** For each DELETE change, the function checks if the target database
12369** contains a row with the same primary key value (or values) as the
12370** original row values stored in the changeset. If it does, and the values
12371** stored in all non-primary key columns also match the values stored in
12372** the changeset the row is deleted from the target database.
12373**
12374** If a row with matching primary key values is found, but one or more of
12375** the non-primary key fields contains a value different from the original
12376** row value stored in the changeset, the conflict-handler function is
12377** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the
12378** database table has more columns than are recorded in the changeset,
12379** only the values of those non-primary key fields are compared against
12380** the current database contents - any trailing database table columns
12381** are ignored.
12382**
12383** If no row with matching primary key values is found in the database,
12384** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
12385** passed as the second argument.
12386**
12387** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT
12388** (which can only happen if a foreign key constraint is violated), the
12389** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT]
12390** passed as the second argument. This includes the case where the DELETE
12391** operation is attempted because an earlier call to the conflict handler
12392** function returned [SQLITE_CHANGESET_REPLACE].
12393**
12394** <dt>INSERT Changes<dd>
12395** For each INSERT change, an attempt is made to insert the new row into
12396** the database. If the changeset row contains fewer fields than the
12397** database table, the trailing fields are populated with their default
12398** values.
12399**
12400** If the attempt to insert the row fails because the database already
12401** contains a row with the same primary key values, the conflict handler
12402** function is invoked with the second argument set to
12403** [SQLITE_CHANGESET_CONFLICT].
12404**
12405** If the attempt to insert the row fails because of some other constraint
12406** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is
12407** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT].
12408** This includes the case where the INSERT operation is re-attempted because
12409** an earlier call to the conflict handler function returned
12410** [SQLITE_CHANGESET_REPLACE].
12411**
12412** <dt>UPDATE Changes<dd>
12413** For each UPDATE change, the function checks if the target database
12414** contains a row with the same primary key value (or values) as the
12415** original row values stored in the changeset. If it does, and the values
12416** stored in all modified non-primary key columns also match the values
12417** stored in the changeset the row is updated within the target database.
12418**
12419** If a row with matching primary key values is found, but one or more of
12420** the modified non-primary key fields contains a value different from an
12421** original row value stored in the changeset, the conflict-handler function
12422** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since
12423** UPDATE changes only contain values for non-primary key fields that are
12424** to be modified, only those fields need to match the original values to
12425** avoid the SQLITE_CHANGESET_DATA conflict-handler callback.
12426**
12427** If no row with matching primary key values is found in the database,
12428** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
12429** passed as the second argument.
12430**
12431** If the UPDATE operation is attempted, but SQLite returns
12432** SQLITE_CONSTRAINT, the conflict-handler function is invoked with
12433** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument.
12434** This includes the case where the UPDATE operation is attempted after
12435** an earlier call to the conflict handler function returned
12436** [SQLITE_CHANGESET_REPLACE].
12437** </dl>
12438**
12439** It is safe to execute SQL statements, including those that write to the
12440** table that the callback related to, from within the xConflict callback.
12441** This can be used to further customize the application's conflict
12442** resolution strategy.
12443**
12444** All changes made by these functions are enclosed in a savepoint transaction.
12445** If any other error (aside from a constraint failure when attempting to
12446** write to the target database) occurs, then the savepoint transaction is
12447** rolled back, restoring the target database to its original state, and an
12448** SQLite error code returned.
12449**
12450** If the output parameters (ppRebase) and (pnRebase) are non-NULL and
12451** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2()
12452** may set (*ppRebase) to point to a "rebase" that may be used with the
12453** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase)
12454** is set to the size of the buffer in bytes. It is the responsibility of the
12455** caller to eventually free any such buffer using sqlite3_free(). The buffer
12456** is only allocated and populated if one or more conflicts were encountered
12457** while applying the patchset. See comments surrounding the sqlite3_rebaser
12458** APIs for further details.
12459**
12460** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent
12461** may be modified by passing a combination of
12462** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter.
12463**
12464** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b>
12465** and therefore subject to change.
12466*/
12467SQLITE_API int sqlite3changeset_apply(
12468 sqlite3 *db, /* Apply change to "main" db of this handle */
12469 int nChangeset, /* Size of changeset in bytes */
12470 void *pChangeset, /* Changeset blob */
12471 int(*xFilter)(
12472 void *pCtx, /* Copy of sixth arg to _apply() */
12473 const char *zTab /* Table name */
12474 ),
12475 int(*xConflict)(
12476 void *pCtx, /* Copy of sixth arg to _apply() */
12477 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12478 sqlite3_changeset_iter *p /* Handle describing change and conflict */
12479 ),
12480 void *pCtx /* First argument passed to xConflict */
12481);
12482SQLITE_API int sqlite3changeset_apply_v2(
12483 sqlite3 *db, /* Apply change to "main" db of this handle */
12484 int nChangeset, /* Size of changeset in bytes */
12485 void *pChangeset, /* Changeset blob */
12486 int(*xFilter)(
12487 void *pCtx, /* Copy of sixth arg to _apply() */
12488 const char *zTab /* Table name */
12489 ),
12490 int(*xConflict)(
12491 void *pCtx, /* Copy of sixth arg to _apply() */
12492 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12493 sqlite3_changeset_iter *p /* Handle describing change and conflict */
12494 ),
12495 void *pCtx, /* First argument passed to xConflict */
12496 void **ppRebase, int *pnRebase, /* OUT: Rebase data */
12497 int flags /* SESSION_CHANGESETAPPLY_* flags */
12498);
12499
12500/*
12501** CAPI3REF: Flags for sqlite3changeset_apply_v2
12502**
12503** The following flags may passed via the 9th parameter to
12504** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]:
12505**
12506** <dl>
12507** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd>
12508** Usually, the sessions module encloses all operations performed by
12509** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The
12510** SAVEPOINT is committed if the changeset or patchset is successfully
12511** applied, or rolled back if an error occurs. Specifying this flag
12512** causes the sessions module to omit this savepoint. In this case, if the
12513** caller has an open transaction or savepoint when apply_v2() is called,
12514** it may revert the partially applied changeset by rolling it back.
12515**
12516** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>
12517** Invert the changeset before applying it. This is equivalent to inverting
12518** a changeset using sqlite3changeset_invert() before applying it. It is
12519** an error to specify this flag with a patchset.
12520**
12521** <dt>SQLITE_CHANGESETAPPLY_IGNORENOOP <dd>
12522** Do not invoke the conflict handler callback for any changes that
12523** would not actually modify the database even if they were applied.
12524** Specifically, this means that the conflict handler is not invoked
12525** for:
12526** <ul>
12527** <li>a delete change if the row being deleted cannot be found,
12528** <li>an update change if the modified fields are already set to
12529** their new values in the conflicting row, or
12530** <li>an insert change if all fields of the conflicting row match
12531** the row being inserted.
12532** </ul>
12533**
12534** <dt>SQLITE_CHANGESETAPPLY_FKNOACTION <dd>
12535** If this flag it set, then all foreign key constraints in the target
12536** database behave as if they were declared with "ON UPDATE NO ACTION ON
12537** DELETE NO ACTION", even if they are actually CASCADE, RESTRICT, SET NULL
12538** or SET DEFAULT.
12539*/
12540#define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001
12541#define SQLITE_CHANGESETAPPLY_INVERT 0x0002
12542#define SQLITE_CHANGESETAPPLY_IGNORENOOP 0x0004
12543#define SQLITE_CHANGESETAPPLY_FKNOACTION 0x0008
12544
12545/*
12546** CAPI3REF: Constants Passed To The Conflict Handler
12547**
12548** Values that may be passed as the second argument to a conflict-handler.
12549**
12550** <dl>
12551** <dt>SQLITE_CHANGESET_DATA<dd>
12552** The conflict handler is invoked with CHANGESET_DATA as the second argument
12553** when processing a DELETE or UPDATE change if a row with the required
12554** PRIMARY KEY fields is present in the database, but one or more other
12555** (non primary-key) fields modified by the update do not contain the
12556** expected "before" values.
12557**
12558** The conflicting row, in this case, is the database row with the matching
12559** primary key.
12560**
12561** <dt>SQLITE_CHANGESET_NOTFOUND<dd>
12562** The conflict handler is invoked with CHANGESET_NOTFOUND as the second
12563** argument when processing a DELETE or UPDATE change if a row with the
12564** required PRIMARY KEY fields is not present in the database.
12565**
12566** There is no conflicting row in this case. The results of invoking the
12567** sqlite3changeset_conflict() API are undefined.
12568**
12569** <dt>SQLITE_CHANGESET_CONFLICT<dd>
12570** CHANGESET_CONFLICT is passed as the second argument to the conflict
12571** handler while processing an INSERT change if the operation would result
12572** in duplicate primary key values.
12573**
12574** The conflicting row in this case is the database row with the matching
12575** primary key.
12576**
12577** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd>
12578** If foreign key handling is enabled, and applying a changeset leaves the
12579** database in a state containing foreign key violations, the conflict
12580** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument
12581** exactly once before the changeset is committed. If the conflict handler
12582** returns CHANGESET_OMIT, the changes, including those that caused the
12583** foreign key constraint violation, are committed. Or, if it returns
12584** CHANGESET_ABORT, the changeset is rolled back.
12585**
12586** No current or conflicting row information is provided. The only function
12587** it is possible to call on the supplied sqlite3_changeset_iter handle
12588** is sqlite3changeset_fk_conflicts().
12589**
12590** <dt>SQLITE_CHANGESET_CONSTRAINT<dd>
12591** If any other constraint violation occurs while applying a change (i.e.
12592** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is
12593** invoked with CHANGESET_CONSTRAINT as the second argument.
12594**
12595** There is no conflicting row in this case. The results of invoking the
12596** sqlite3changeset_conflict() API are undefined.
12597**
12598** </dl>
12599*/
12600#define SQLITE_CHANGESET_DATA 1
12601#define SQLITE_CHANGESET_NOTFOUND 2
12602#define SQLITE_CHANGESET_CONFLICT 3
12603#define SQLITE_CHANGESET_CONSTRAINT 4
12604#define SQLITE_CHANGESET_FOREIGN_KEY 5
12605
12606/*
12607** CAPI3REF: Constants Returned By The Conflict Handler
12608**
12609** A conflict handler callback must return one of the following three values.
12610**
12611** <dl>
12612** <dt>SQLITE_CHANGESET_OMIT<dd>
12613** If a conflict handler returns this value no special action is taken. The
12614** change that caused the conflict is not applied. The session module
12615** continues to the next change in the changeset.
12616**
12617** <dt>SQLITE_CHANGESET_REPLACE<dd>
12618** This value may only be returned if the second argument to the conflict
12619** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this
12620** is not the case, any changes applied so far are rolled back and the
12621** call to sqlite3changeset_apply() returns SQLITE_MISUSE.
12622**
12623** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict
12624** handler, then the conflicting row is either updated or deleted, depending
12625** on the type of change.
12626**
12627** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict
12628** handler, then the conflicting row is removed from the database and a
12629** second attempt to apply the change is made. If this second attempt fails,
12630** the original row is restored to the database before continuing.
12631**
12632** <dt>SQLITE_CHANGESET_ABORT<dd>
12633** If this value is returned, any changes applied so far are rolled back
12634** and the call to sqlite3changeset_apply() returns SQLITE_ABORT.
12635** </dl>
12636*/
12637#define SQLITE_CHANGESET_OMIT 0
12638#define SQLITE_CHANGESET_REPLACE 1
12639#define SQLITE_CHANGESET_ABORT 2
12640
12641/*
12642** CAPI3REF: Rebasing changesets
12643** EXPERIMENTAL
12644**
12645** Suppose there is a site hosting a database in state S0. And that
12646** modifications are made that move that database to state S1 and a
12647** changeset recorded (the "local" changeset). Then, a changeset based
12648** on S0 is received from another site (the "remote" changeset) and
12649** applied to the database. The database is then in state
12650** (S1+"remote"), where the exact state depends on any conflict
12651** resolution decisions (OMIT or REPLACE) made while applying "remote".
12652** Rebasing a changeset is to update it to take those conflict
12653** resolution decisions into account, so that the same conflicts
12654** do not have to be resolved elsewhere in the network.
12655**
12656** For example, if both the local and remote changesets contain an
12657** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)":
12658**
12659** local: INSERT INTO t1 VALUES(1, 'v1');
12660** remote: INSERT INTO t1 VALUES(1, 'v2');
12661**
12662** and the conflict resolution is REPLACE, then the INSERT change is
12663** removed from the local changeset (it was overridden). Or, if the
12664** conflict resolution was "OMIT", then the local changeset is modified
12665** to instead contain:
12666**
12667** UPDATE t1 SET b = 'v2' WHERE a=1;
12668**
12669** Changes within the local changeset are rebased as follows:
12670**
12671** <dl>
12672** <dt>Local INSERT<dd>
12673** This may only conflict with a remote INSERT. If the conflict
12674** resolution was OMIT, then add an UPDATE change to the rebased
12675** changeset. Or, if the conflict resolution was REPLACE, add
12676** nothing to the rebased changeset.
12677**
12678** <dt>Local DELETE<dd>
12679** This may conflict with a remote UPDATE or DELETE. In both cases the
12680** only possible resolution is OMIT. If the remote operation was a
12681** DELETE, then add no change to the rebased changeset. If the remote
12682** operation was an UPDATE, then the old.* fields of change are updated
12683** to reflect the new.* values in the UPDATE.
12684**
12685** <dt>Local UPDATE<dd>
12686** This may conflict with a remote UPDATE or DELETE. If it conflicts
12687** with a DELETE, and the conflict resolution was OMIT, then the update
12688** is changed into an INSERT. Any undefined values in the new.* record
12689** from the update change are filled in using the old.* values from
12690** the conflicting DELETE. Or, if the conflict resolution was REPLACE,
12691** the UPDATE change is simply omitted from the rebased changeset.
12692**
12693** If conflict is with a remote UPDATE and the resolution is OMIT, then
12694** the old.* values are rebased using the new.* values in the remote
12695** change. Or, if the resolution is REPLACE, then the change is copied
12696** into the rebased changeset with updates to columns also updated by
12697** the conflicting remote UPDATE removed. If this means no columns would
12698** be updated, the change is omitted.
12699** </dl>
12700**
12701** A local change may be rebased against multiple remote changes
12702** simultaneously. If a single key is modified by multiple remote
12703** changesets, they are combined as follows before the local changeset
12704** is rebased:
12705**
12706** <ul>
12707** <li> If there has been one or more REPLACE resolutions on a
12708** key, it is rebased according to a REPLACE.
12709**
12710** <li> If there have been no REPLACE resolutions on a key, then
12711** the local changeset is rebased according to the most recent
12712** of the OMIT resolutions.
12713** </ul>
12714**
12715** Note that conflict resolutions from multiple remote changesets are
12716** combined on a per-field basis, not per-row. This means that in the
12717** case of multiple remote UPDATE operations, some fields of a single
12718** local change may be rebased for REPLACE while others are rebased for
12719** OMIT.
12720**
12721** In order to rebase a local changeset, the remote changeset must first
12722** be applied to the local database using sqlite3changeset_apply_v2() and
12723** the buffer of rebase information captured. Then:
12724**
12725** <ol>
12726** <li> An sqlite3_rebaser object is created by calling
12727** sqlite3rebaser_create().
12728** <li> The new object is configured with the rebase buffer obtained from
12729** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure().
12730** If the local changeset is to be rebased against multiple remote
12731** changesets, then sqlite3rebaser_configure() should be called
12732** multiple times, in the same order that the multiple
12733** sqlite3changeset_apply_v2() calls were made.
12734** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase().
12735** <li> The sqlite3_rebaser object is deleted by calling
12736** sqlite3rebaser_delete().
12737** </ol>
12738*/
12739typedef struct sqlite3_rebaser sqlite3_rebaser;
12740
12741/*
12742** CAPI3REF: Create a changeset rebaser object.
12743** EXPERIMENTAL
12744**
12745** Allocate a new changeset rebaser object. If successful, set (*ppNew) to
12746** point to the new object and return SQLITE_OK. Otherwise, if an error
12747** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew)
12748** to NULL.
12749*/
12750SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew);
12751
12752/*
12753** CAPI3REF: Configure a changeset rebaser object.
12754** EXPERIMENTAL
12755**
12756** Configure the changeset rebaser object to rebase changesets according
12757** to the conflict resolutions described by buffer pRebase (size nRebase
12758** bytes), which must have been obtained from a previous call to
12759** sqlite3changeset_apply_v2().
12760*/
12761SQLITE_API int sqlite3rebaser_configure(
12762 sqlite3_rebaser*,
12763 int nRebase, const void *pRebase
12764);
12765
12766/*
12767** CAPI3REF: Rebase a changeset
12768** EXPERIMENTAL
12769**
12770** Argument pIn must point to a buffer containing a changeset nIn bytes
12771** in size. This function allocates and populates a buffer with a copy
12772** of the changeset rebased according to the configuration of the
12773** rebaser object passed as the first argument. If successful, (*ppOut)
12774** is set to point to the new buffer containing the rebased changeset and
12775** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the
12776** responsibility of the caller to eventually free the new buffer using
12777** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut)
12778** are set to zero and an SQLite error code returned.
12779*/
12780SQLITE_API int sqlite3rebaser_rebase(
12781 sqlite3_rebaser*,
12782 int nIn, const void *pIn,
12783 int *pnOut, void **ppOut
12784);
12785
12786/*
12787** CAPI3REF: Delete a changeset rebaser object.
12788** EXPERIMENTAL
12789**
12790** Delete the changeset rebaser object and all associated resources. There
12791** should be one call to this function for each successful invocation
12792** of sqlite3rebaser_create().
12793*/
12794SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p);
12795
12796/*
12797** CAPI3REF: Streaming Versions of API functions.
12798**
12799** The six streaming API xxx_strm() functions serve similar purposes to the
12800** corresponding non-streaming API functions:
12801**
12802** <table border=1 style="margin-left:8ex;margin-right:8ex">
12803** <tr><th>Streaming function<th>Non-streaming equivalent</th>
12804** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply]
12805** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2]
12806** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat]
12807** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert]
12808** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start]
12809** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset]
12810** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset]
12811** </table>
12812**
12813** Non-streaming functions that accept changesets (or patchsets) as input
12814** require that the entire changeset be stored in a single buffer in memory.
12815** Similarly, those that return a changeset or patchset do so by returning
12816** a pointer to a single large buffer allocated using sqlite3_malloc().
12817** Normally this is convenient. However, if an application running in a
12818** low-memory environment is required to handle very large changesets, the
12819** large contiguous memory allocations required can become onerous.
12820**
12821** In order to avoid this problem, instead of a single large buffer, input
12822** is passed to a streaming API functions by way of a callback function that
12823** the sessions module invokes to incrementally request input data as it is
12824** required. In all cases, a pair of API function parameters such as
12825**
12826** <pre>
12827** int nChangeset,
12828** void *pChangeset,
12829** </pre>
12830**
12831** Is replaced by:
12832**
12833** <pre>
12834** int (*xInput)(void *pIn, void *pData, int *pnData),
12835** void *pIn,
12836** </pre>
12837**
12838** Each time the xInput callback is invoked by the sessions module, the first
12839** argument passed is a copy of the supplied pIn context pointer. The second
12840** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no
12841** error occurs the xInput method should copy up to (*pnData) bytes of data
12842** into the buffer and set (*pnData) to the actual number of bytes copied
12843** before returning SQLITE_OK. If the input is completely exhausted, (*pnData)
12844** should be set to zero to indicate this. Or, if an error occurs, an SQLite
12845** error code should be returned. In all cases, if an xInput callback returns
12846** an error, all processing is abandoned and the streaming API function
12847** returns a copy of the error code to the caller.
12848**
12849** In the case of sqlite3changeset_start_strm(), the xInput callback may be
12850** invoked by the sessions module at any point during the lifetime of the
12851** iterator. If such an xInput callback returns an error, the iterator enters
12852** an error state, whereby all subsequent calls to iterator functions
12853** immediately fail with the same error code as returned by xInput.
12854**
12855** Similarly, streaming API functions that return changesets (or patchsets)
12856** return them in chunks by way of a callback function instead of via a
12857** pointer to a single large buffer. In this case, a pair of parameters such
12858** as:
12859**
12860** <pre>
12861** int *pnChangeset,
12862** void **ppChangeset,
12863** </pre>
12864**
12865** Is replaced by:
12866**
12867** <pre>
12868** int (*xOutput)(void *pOut, const void *pData, int nData),
12869** void *pOut
12870** </pre>
12871**
12872** The xOutput callback is invoked zero or more times to return data to
12873** the application. The first parameter passed to each call is a copy of the
12874** pOut pointer supplied by the application. The second parameter, pData,
12875** points to a buffer nData bytes in size containing the chunk of output
12876** data being returned. If the xOutput callback successfully processes the
12877** supplied data, it should return SQLITE_OK to indicate success. Otherwise,
12878** it should return some other SQLite error code. In this case processing
12879** is immediately abandoned and the streaming API function returns a copy
12880** of the xOutput error code to the application.
12881**
12882** The sessions module never invokes an xOutput callback with the third
12883** parameter set to a value less than or equal to zero. Other than this,
12884** no guarantees are made as to the size of the chunks of data returned.
12885*/
12886SQLITE_API int sqlite3changeset_apply_strm(
12887 sqlite3 *db, /* Apply change to "main" db of this handle */
12888 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
12889 void *pIn, /* First arg for xInput */
12890 int(*xFilter)(
12891 void *pCtx, /* Copy of sixth arg to _apply() */
12892 const char *zTab /* Table name */
12893 ),
12894 int(*xConflict)(
12895 void *pCtx, /* Copy of sixth arg to _apply() */
12896 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12897 sqlite3_changeset_iter *p /* Handle describing change and conflict */
12898 ),
12899 void *pCtx /* First argument passed to xConflict */
12900);
12901SQLITE_API int sqlite3changeset_apply_v2_strm(
12902 sqlite3 *db, /* Apply change to "main" db of this handle */
12903 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
12904 void *pIn, /* First arg for xInput */
12905 int(*xFilter)(
12906 void *pCtx, /* Copy of sixth arg to _apply() */
12907 const char *zTab /* Table name */
12908 ),
12909 int(*xConflict)(
12910 void *pCtx, /* Copy of sixth arg to _apply() */
12911 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12912 sqlite3_changeset_iter *p /* Handle describing change and conflict */
12913 ),
12914 void *pCtx, /* First argument passed to xConflict */
12915 void **ppRebase, int *pnRebase,
12916 int flags
12917);
12918SQLITE_API int sqlite3changeset_concat_strm(
12919 int (*xInputA)(void *pIn, void *pData, int *pnData),
12920 void *pInA,
12921 int (*xInputB)(void *pIn, void *pData, int *pnData),
12922 void *pInB,
12923 int (*xOutput)(void *pOut, const void *pData, int nData),
12924 void *pOut
12925);
12926SQLITE_API int sqlite3changeset_invert_strm(
12927 int (*xInput)(void *pIn, void *pData, int *pnData),
12928 void *pIn,
12929 int (*xOutput)(void *pOut, const void *pData, int nData),
12930 void *pOut
12931);
12932SQLITE_API int sqlite3changeset_start_strm(
12933 sqlite3_changeset_iter **pp,
12934 int (*xInput)(void *pIn, void *pData, int *pnData),
12935 void *pIn
12936);
12937SQLITE_API int sqlite3changeset_start_v2_strm(
12938 sqlite3_changeset_iter **pp,
12939 int (*xInput)(void *pIn, void *pData, int *pnData),
12940 void *pIn,
12941 int flags
12942);
12943SQLITE_API int sqlite3session_changeset_strm(
12944 sqlite3_session *pSession,
12945 int (*xOutput)(void *pOut, const void *pData, int nData),
12946 void *pOut
12947);
12948SQLITE_API int sqlite3session_patchset_strm(
12949 sqlite3_session *pSession,
12950 int (*xOutput)(void *pOut, const void *pData, int nData),
12951 void *pOut
12952);
12953SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*,
12954 int (*xInput)(void *pIn, void *pData, int *pnData),
12955 void *pIn
12956);
12957SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*,
12958 int (*xOutput)(void *pOut, const void *pData, int nData),
12959 void *pOut
12960);
12961SQLITE_API int sqlite3rebaser_rebase_strm(
12962 sqlite3_rebaser *pRebaser,
12963 int (*xInput)(void *pIn, void *pData, int *pnData),
12964 void *pIn,
12965 int (*xOutput)(void *pOut, const void *pData, int nData),
12966 void *pOut
12967);
12968
12969/*
12970** CAPI3REF: Configure global parameters
12971**
12972** The sqlite3session_config() interface is used to make global configuration
12973** changes to the sessions module in order to tune it to the specific needs
12974** of the application.
12975**
12976** The sqlite3session_config() interface is not threadsafe. If it is invoked
12977** while any other thread is inside any other sessions method then the
12978** results are undefined. Furthermore, if it is invoked after any sessions
12979** related objects have been created, the results are also undefined.
12980**
12981** The first argument to the sqlite3session_config() function must be one
12982** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The
12983** interpretation of the (void*) value passed as the second parameter and
12984** the effect of calling this function depends on the value of the first
12985** parameter.
12986**
12987** <dl>
12988** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd>
12989** By default, the sessions module streaming interfaces attempt to input
12990** and output data in approximately 1 KiB chunks. This operand may be used
12991** to set and query the value of this configuration setting. The pointer
12992** passed as the second argument must point to a value of type (int).
12993** If this value is greater than 0, it is used as the new streaming data
12994** chunk size for both input and output. Before returning, the (int) value
12995** pointed to by pArg is set to the final value of the streaming interface
12996** chunk size.
12997** </dl>
12998**
12999** This function returns SQLITE_OK if successful, or an SQLite error code
13000** otherwise.
13001*/
13002SQLITE_API int sqlite3session_config(int op, void *pArg);
13003
13004/*
13005** CAPI3REF: Values for sqlite3session_config().
13006*/
13007#define SQLITE_SESSION_CONFIG_STRMSIZE 1
13008
13009/*
13010** Make sure we can call this stuff from C++.
13011*/
13012#ifdef __cplusplus
13013}
13014#endif
13015
13016#endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */
13017
13018/******** End of sqlite3session.h *********/
13019/******** Begin file fts5.h *********/
13020/*
13021** 2014 May 31
13022**
13023** The author disclaims copyright to this source code. In place of
13024** a legal notice, here is a blessing:
13025**
13026** May you do good and not evil.
13027** May you find forgiveness for yourself and forgive others.
13028** May you share freely, never taking more than you give.
13029**
13030******************************************************************************
13031**
13032** Interfaces to extend FTS5. Using the interfaces defined in this file,
13033** FTS5 may be extended with:
13034**
13035** * custom tokenizers, and
13036** * custom auxiliary functions.
13037*/
13038
13039
13040#ifndef _FTS5_H
13041#define _FTS5_H
13042
13043
13044#ifdef __cplusplus
13045extern "C" {
13046#endif
13047
13048/*************************************************************************
13049** CUSTOM AUXILIARY FUNCTIONS
13050**
13051** Virtual table implementations may overload SQL functions by implementing
13052** the sqlite3_module.xFindFunction() method.
13053*/
13054
13055typedef struct Fts5ExtensionApi Fts5ExtensionApi;
13056typedef struct Fts5Context Fts5Context;
13057typedef struct Fts5PhraseIter Fts5PhraseIter;
13058
13059typedef void (*fts5_extension_function)(
13060 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */
13061 Fts5Context *pFts, /* First arg to pass to pApi functions */
13062 sqlite3_context *pCtx, /* Context for returning result/error */
13063 int nVal, /* Number of values in apVal[] array */
13064 sqlite3_value **apVal /* Array of trailing arguments */
13065);
13066
13067struct Fts5PhraseIter {
13068 const unsigned char *a;
13069 const unsigned char *b;
13070};
13071
13072/*
13073** EXTENSION API FUNCTIONS
13074**
13075** xUserData(pFts):
13076** Return a copy of the pUserData pointer passed to the xCreateFunction()
13077** API when the extension function was registered.
13078**
13079** xColumnTotalSize(pFts, iCol, pnToken):
13080** If parameter iCol is less than zero, set output variable *pnToken
13081** to the total number of tokens in the FTS5 table. Or, if iCol is
13082** non-negative but less than the number of columns in the table, return
13083** the total number of tokens in column iCol, considering all rows in
13084** the FTS5 table.
13085**
13086** If parameter iCol is greater than or equal to the number of columns
13087** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
13088** an OOM condition or IO error), an appropriate SQLite error code is
13089** returned.
13090**
13091** xColumnCount(pFts):
13092** Return the number of columns in the table.
13093**
13094** xColumnSize(pFts, iCol, pnToken):
13095** If parameter iCol is less than zero, set output variable *pnToken
13096** to the total number of tokens in the current row. Or, if iCol is
13097** non-negative but less than the number of columns in the table, set
13098** *pnToken to the number of tokens in column iCol of the current row.
13099**
13100** If parameter iCol is greater than or equal to the number of columns
13101** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
13102** an OOM condition or IO error), an appropriate SQLite error code is
13103** returned.
13104**
13105** This function may be quite inefficient if used with an FTS5 table
13106** created with the "columnsize=0" option.
13107**
13108** xColumnText:
13109** If parameter iCol is less than zero, or greater than or equal to the
13110** number of columns in the table, SQLITE_RANGE is returned.
13111**
13112** Otherwise, this function attempts to retrieve the text of column iCol of
13113** the current document. If successful, (*pz) is set to point to a buffer
13114** containing the text in utf-8 encoding, (*pn) is set to the size in bytes
13115** (not characters) of the buffer and SQLITE_OK is returned. Otherwise,
13116** if an error occurs, an SQLite error code is returned and the final values
13117** of (*pz) and (*pn) are undefined.
13118**
13119** xPhraseCount:
13120** Returns the number of phrases in the current query expression.
13121**
13122** xPhraseSize:
13123** If parameter iCol is less than zero, or greater than or equal to the
13124** number of phrases in the current query, as returned by xPhraseCount,
13125** 0 is returned. Otherwise, this function returns the number of tokens in
13126** phrase iPhrase of the query. Phrases are numbered starting from zero.
13127**
13128** xInstCount:
13129** Set *pnInst to the total number of occurrences of all phrases within
13130** the query within the current row. Return SQLITE_OK if successful, or
13131** an error code (i.e. SQLITE_NOMEM) if an error occurs.
13132**
13133** This API can be quite slow if used with an FTS5 table created with the
13134** "detail=none" or "detail=column" option. If the FTS5 table is created
13135** with either "detail=none" or "detail=column" and "content=" option
13136** (i.e. if it is a contentless table), then this API always returns 0.
13137**
13138** xInst:
13139** Query for the details of phrase match iIdx within the current row.
13140** Phrase matches are numbered starting from zero, so the iIdx argument
13141** should be greater than or equal to zero and smaller than the value
13142** output by xInstCount(). If iIdx is less than zero or greater than
13143** or equal to the value returned by xInstCount(), SQLITE_RANGE is returned.
13144**
13145** Otherwise, output parameter *piPhrase is set to the phrase number, *piCol
13146** to the column in which it occurs and *piOff the token offset of the
13147** first token of the phrase. SQLITE_OK is returned if successful, or an
13148** error code (i.e. SQLITE_NOMEM) if an error occurs.
13149**
13150** This API can be quite slow if used with an FTS5 table created with the
13151** "detail=none" or "detail=column" option.
13152**
13153** xRowid:
13154** Returns the rowid of the current row.
13155**
13156** xTokenize:
13157** Tokenize text using the tokenizer belonging to the FTS5 table.
13158**
13159** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback):
13160** This API function is used to query the FTS table for phrase iPhrase
13161** of the current query. Specifically, a query equivalent to:
13162**
13163** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid
13164**
13165** with $p set to a phrase equivalent to the phrase iPhrase of the
13166** current query is executed. Any column filter that applies to
13167** phrase iPhrase of the current query is included in $p. For each
13168** row visited, the callback function passed as the fourth argument
13169** is invoked. The context and API objects passed to the callback
13170** function may be used to access the properties of each matched row.
13171** Invoking Api.xUserData() returns a copy of the pointer passed as
13172** the third argument to pUserData.
13173**
13174** If parameter iPhrase is less than zero, or greater than or equal to
13175** the number of phrases in the query, as returned by xPhraseCount(),
13176** this function returns SQLITE_RANGE.
13177**
13178** If the callback function returns any value other than SQLITE_OK, the
13179** query is abandoned and the xQueryPhrase function returns immediately.
13180** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK.
13181** Otherwise, the error code is propagated upwards.
13182**
13183** If the query runs to completion without incident, SQLITE_OK is returned.
13184** Or, if some error occurs before the query completes or is aborted by
13185** the callback, an SQLite error code is returned.
13186**
13187**
13188** xSetAuxdata(pFts5, pAux, xDelete)
13189**
13190** Save the pointer passed as the second argument as the extension function's
13191** "auxiliary data". The pointer may then be retrieved by the current or any
13192** future invocation of the same fts5 extension function made as part of
13193** the same MATCH query using the xGetAuxdata() API.
13194**
13195** Each extension function is allocated a single auxiliary data slot for
13196** each FTS query (MATCH expression). If the extension function is invoked
13197** more than once for a single FTS query, then all invocations share a
13198** single auxiliary data context.
13199**
13200** If there is already an auxiliary data pointer when this function is
13201** invoked, then it is replaced by the new pointer. If an xDelete callback
13202** was specified along with the original pointer, it is invoked at this
13203** point.
13204**
13205** The xDelete callback, if one is specified, is also invoked on the
13206** auxiliary data pointer after the FTS5 query has finished.
13207**
13208** If an error (e.g. an OOM condition) occurs within this function,
13209** the auxiliary data is set to NULL and an error code returned. If the
13210** xDelete parameter was not NULL, it is invoked on the auxiliary data
13211** pointer before returning.
13212**
13213**
13214** xGetAuxdata(pFts5, bClear)
13215**
13216** Returns the current auxiliary data pointer for the fts5 extension
13217** function. See the xSetAuxdata() method for details.
13218**
13219** If the bClear argument is non-zero, then the auxiliary data is cleared
13220** (set to NULL) before this function returns. In this case the xDelete,
13221** if any, is not invoked.
13222**
13223**
13224** xRowCount(pFts5, pnRow)
13225**
13226** This function is used to retrieve the total number of rows in the table.
13227** In other words, the same value that would be returned by:
13228**
13229** SELECT count(*) FROM ftstable;
13230**
13231** xPhraseFirst()
13232** This function is used, along with type Fts5PhraseIter and the xPhraseNext
13233** method, to iterate through all instances of a single query phrase within
13234** the current row. This is the same information as is accessible via the
13235** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient
13236** to use, this API may be faster under some circumstances. To iterate
13237** through instances of phrase iPhrase, use the following code:
13238**
13239** Fts5PhraseIter iter;
13240** int iCol, iOff;
13241** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff);
13242** iCol>=0;
13243** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff)
13244** ){
13245** // An instance of phrase iPhrase at offset iOff of column iCol
13246** }
13247**
13248** The Fts5PhraseIter structure is defined above. Applications should not
13249** modify this structure directly - it should only be used as shown above
13250** with the xPhraseFirst() and xPhraseNext() API methods (and by
13251** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below).
13252**
13253** This API can be quite slow if used with an FTS5 table created with the
13254** "detail=none" or "detail=column" option. If the FTS5 table is created
13255** with either "detail=none" or "detail=column" and "content=" option
13256** (i.e. if it is a contentless table), then this API always iterates
13257** through an empty set (all calls to xPhraseFirst() set iCol to -1).
13258**
13259** In all cases, matches are visited in (column ASC, offset ASC) order.
13260** i.e. all those in column 0, sorted by offset, followed by those in
13261** column 1, etc.
13262**
13263** xPhraseNext()
13264** See xPhraseFirst above.
13265**
13266** xPhraseFirstColumn()
13267** This function and xPhraseNextColumn() are similar to the xPhraseFirst()
13268** and xPhraseNext() APIs described above. The difference is that instead
13269** of iterating through all instances of a phrase in the current row, these
13270** APIs are used to iterate through the set of columns in the current row
13271** that contain one or more instances of a specified phrase. For example:
13272**
13273** Fts5PhraseIter iter;
13274** int iCol;
13275** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol);
13276** iCol>=0;
13277** pApi->xPhraseNextColumn(pFts, &iter, &iCol)
13278** ){
13279** // Column iCol contains at least one instance of phrase iPhrase
13280** }
13281**
13282** This API can be quite slow if used with an FTS5 table created with the
13283** "detail=none" option. If the FTS5 table is created with either
13284** "detail=none" "content=" option (i.e. if it is a contentless table),
13285** then this API always iterates through an empty set (all calls to
13286** xPhraseFirstColumn() set iCol to -1).
13287**
13288** The information accessed using this API and its companion
13289** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext
13290** (or xInst/xInstCount). The chief advantage of this API is that it is
13291** significantly more efficient than those alternatives when used with
13292** "detail=column" tables.
13293**
13294** xPhraseNextColumn()
13295** See xPhraseFirstColumn above.
13296**
13297** xQueryToken(pFts5, iPhrase, iToken, ppToken, pnToken)
13298** This is used to access token iToken of phrase iPhrase of the current
13299** query. Before returning, output parameter *ppToken is set to point
13300** to a buffer containing the requested token, and *pnToken to the
13301** size of this buffer in bytes.
13302**
13303** If iPhrase or iToken are less than zero, or if iPhrase is greater than
13304** or equal to the number of phrases in the query as reported by
13305** xPhraseCount(), or if iToken is equal to or greater than the number of
13306** tokens in the phrase, SQLITE_RANGE is returned and *ppToken and *pnToken
13307 are both zeroed.
13308**
13309** The output text is not a copy of the query text that specified the
13310** token. It is the output of the tokenizer module. For tokendata=1
13311** tables, this includes any embedded 0x00 and trailing data.
13312**
13313** xInstToken(pFts5, iIdx, iToken, ppToken, pnToken)
13314** This is used to access token iToken of phrase hit iIdx within the
13315** current row. If iIdx is less than zero or greater than or equal to the
13316** value returned by xInstCount(), SQLITE_RANGE is returned. Otherwise,
13317** output variable (*ppToken) is set to point to a buffer containing the
13318** matching document token, and (*pnToken) to the size of that buffer in
13319** bytes.
13320**
13321** The output text is not a copy of the document text that was tokenized.
13322** It is the output of the tokenizer module. For tokendata=1 tables, this
13323** includes any embedded 0x00 and trailing data.
13324**
13325** This API may be slow in some cases if the token identified by parameters
13326** iIdx and iToken matched a prefix token in the query. In most cases, the
13327** first call to this API for each prefix token in the query is forced
13328** to scan the portion of the full-text index that matches the prefix
13329** token to collect the extra data required by this API. If the prefix
13330** token matches a large number of token instances in the document set,
13331** this may be a performance problem.
13332**
13333** If the user knows in advance that a query may use this API for a
13334** prefix token, FTS5 may be configured to collect all required data as part
13335** of the initial querying of the full-text index, avoiding the second scan
13336** entirely. This also causes prefix queries that do not use this API to
13337** run more slowly and use more memory. FTS5 may be configured in this way
13338** either on a per-table basis using the [FTS5 insttoken | 'insttoken']
13339** option, or on a per-query basis using the
13340** [fts5_insttoken | fts5_insttoken()] user function.
13341**
13342** This API can be quite slow if used with an FTS5 table created with the
13343** "detail=none" or "detail=column" option.
13344**
13345** xColumnLocale(pFts5, iIdx, pzLocale, pnLocale)
13346** If parameter iCol is less than zero, or greater than or equal to the
13347** number of columns in the table, SQLITE_RANGE is returned.
13348**
13349** Otherwise, this function attempts to retrieve the locale associated
13350** with column iCol of the current row. Usually, there is no associated
13351** locale, and output parameters (*pzLocale) and (*pnLocale) are set
13352** to NULL and 0, respectively. However, if the fts5_locale() function
13353** was used to associate a locale with the value when it was inserted
13354** into the fts5 table, then (*pzLocale) is set to point to a nul-terminated
13355** buffer containing the name of the locale in utf-8 encoding. (*pnLocale)
13356** is set to the size in bytes of the buffer, not including the
13357** nul-terminator.
13358**
13359** If successful, SQLITE_OK is returned. Or, if an error occurs, an
13360** SQLite error code is returned. The final value of the output parameters
13361** is undefined in this case.
13362**
13363** xTokenize_v2:
13364** Tokenize text using the tokenizer belonging to the FTS5 table. This
13365** API is the same as the xTokenize() API, except that it allows a tokenizer
13366** locale to be specified.
13367*/
13368struct Fts5ExtensionApi {
13369 int iVersion; /* Currently always set to 4 */
13370
13371 void *(*xUserData)(Fts5Context*);
13372
13373 int (*xColumnCount)(Fts5Context*);
13374 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow);
13375 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken);
13376
13377 int (*xTokenize)(Fts5Context*,
13378 const char *pText, int nText, /* Text to tokenize */
13379 void *pCtx, /* Context passed to xToken() */
13380 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */
13381 );
13382
13383 int (*xPhraseCount)(Fts5Context*);
13384 int (*xPhraseSize)(Fts5Context*, int iPhrase);
13385
13386 int (*xInstCount)(Fts5Context*, int *pnInst);
13387 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff);
13388
13389 sqlite3_int64 (*xRowid)(Fts5Context*);
13390 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn);
13391 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken);
13392
13393 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData,
13394 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*)
13395 );
13396 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*));
13397 void *(*xGetAuxdata)(Fts5Context*, int bClear);
13398
13399 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*);
13400 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff);
13401
13402 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*);
13403 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol);
13404
13405 /* Below this point are iVersion>=3 only */
13406 int (*xQueryToken)(Fts5Context*,
13407 int iPhrase, int iToken,
13408 const char **ppToken, int *pnToken
13409 );
13410 int (*xInstToken)(Fts5Context*, int iIdx, int iToken, const char**, int*);
13411
13412 /* Below this point are iVersion>=4 only */
13413 int (*xColumnLocale)(Fts5Context*, int iCol, const char **pz, int *pn);
13414 int (*xTokenize_v2)(Fts5Context*,
13415 const char *pText, int nText, /* Text to tokenize */
13416 const char *pLocale, int nLocale, /* Locale to pass to tokenizer */
13417 void *pCtx, /* Context passed to xToken() */
13418 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */
13419 );
13420};
13421
13422/*
13423** CUSTOM AUXILIARY FUNCTIONS
13424*************************************************************************/
13425
13426/*************************************************************************
13427** CUSTOM TOKENIZERS
13428**
13429** Applications may also register custom tokenizer types. A tokenizer
13430** is registered by providing fts5 with a populated instance of the
13431** following structure. All structure methods must be defined, setting
13432** any member of the fts5_tokenizer struct to NULL leads to undefined
13433** behaviour. The structure methods are expected to function as follows:
13434**
13435** xCreate:
13436** This function is used to allocate and initialize a tokenizer instance.
13437** A tokenizer instance is required to actually tokenize text.
13438**
13439** The first argument passed to this function is a copy of the (void*)
13440** pointer provided by the application when the fts5_tokenizer_v2 object
13441** was registered with FTS5 (the third argument to xCreateTokenizer()).
13442** The second and third arguments are an array of nul-terminated strings
13443** containing the tokenizer arguments, if any, specified following the
13444** tokenizer name as part of the CREATE VIRTUAL TABLE statement used
13445** to create the FTS5 table.
13446**
13447** The final argument is an output variable. If successful, (*ppOut)
13448** should be set to point to the new tokenizer handle and SQLITE_OK
13449** returned. If an error occurs, some value other than SQLITE_OK should
13450** be returned. In this case, fts5 assumes that the final value of *ppOut
13451** is undefined.
13452**
13453** xDelete:
13454** This function is invoked to delete a tokenizer handle previously
13455** allocated using xCreate(). Fts5 guarantees that this function will
13456** be invoked exactly once for each successful call to xCreate().
13457**
13458** xTokenize:
13459** This function is expected to tokenize the nText byte string indicated
13460** by argument pText. pText may or may not be nul-terminated. The first
13461** argument passed to this function is a pointer to an Fts5Tokenizer object
13462** returned by an earlier call to xCreate().
13463**
13464** The third argument indicates the reason that FTS5 is requesting
13465** tokenization of the supplied text. This is always one of the following
13466** four values:
13467**
13468** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into
13469** or removed from the FTS table. The tokenizer is being invoked to
13470** determine the set of tokens to add to (or delete from) the
13471** FTS index.
13472**
13473** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed
13474** against the FTS index. The tokenizer is being called to tokenize
13475** a bareword or quoted string specified as part of the query.
13476**
13477** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as
13478** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is
13479** followed by a "*" character, indicating that the last token
13480** returned by the tokenizer will be treated as a token prefix.
13481**
13482** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to
13483** satisfy an fts5_api.xTokenize() request made by an auxiliary
13484** function. Or an fts5_api.xColumnSize() request made by the same
13485** on a columnsize=0 database.
13486** </ul>
13487**
13488** The sixth and seventh arguments passed to xTokenize() - pLocale and
13489** nLocale - are a pointer to a buffer containing the locale to use for
13490** tokenization (e.g. "en_US") and its size in bytes, respectively. The
13491** pLocale buffer is not nul-terminated. pLocale may be passed NULL (in
13492** which case nLocale is always 0) to indicate that the tokenizer should
13493** use its default locale.
13494**
13495** For each token in the input string, the supplied callback xToken() must
13496** be invoked. The first argument to it should be a copy of the pointer
13497** passed as the second argument to xTokenize(). The third and fourth
13498** arguments are a pointer to a buffer containing the token text, and the
13499** size of the token in bytes. The 4th and 5th arguments are the byte offsets
13500** of the first byte of and first byte immediately following the text from
13501** which the token is derived within the input.
13502**
13503** The second argument passed to the xToken() callback ("tflags") should
13504** normally be set to 0. The exception is if the tokenizer supports
13505** synonyms. In this case see the discussion below for details.
13506**
13507** FTS5 assumes the xToken() callback is invoked for each token in the
13508** order that they occur within the input text.
13509**
13510** If an xToken() callback returns any value other than SQLITE_OK, then
13511** the tokenization should be abandoned and the xTokenize() method should
13512** immediately return a copy of the xToken() return value. Or, if the
13513** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally,
13514** if an error occurs with the xTokenize() implementation itself, it
13515** may abandon the tokenization and return any error code other than
13516** SQLITE_OK or SQLITE_DONE.
13517**
13518** If the tokenizer is registered using an fts5_tokenizer_v2 object,
13519** then the xTokenize() method has two additional arguments - pLocale
13520** and nLocale. These specify the locale that the tokenizer should use
13521** for the current request. If pLocale and nLocale are both 0, then the
13522** tokenizer should use its default locale. Otherwise, pLocale points to
13523** an nLocale byte buffer containing the name of the locale to use as utf-8
13524** text. pLocale is not nul-terminated.
13525**
13526** FTS5_TOKENIZER
13527**
13528** There is also an fts5_tokenizer object. This is an older, deprecated,
13529** version of fts5_tokenizer_v2. It is similar except that:
13530**
13531** <ul>
13532** <li> There is no "iVersion" field, and
13533** <li> The xTokenize() method does not take a locale argument.
13534** </ul>
13535**
13536** Legacy fts5_tokenizer tokenizers must be registered using the
13537** legacy xCreateTokenizer() function, instead of xCreateTokenizer_v2().
13538**
13539** Tokenizer implementations registered using either API may be retrieved
13540** using both xFindTokenizer() and xFindTokenizer_v2().
13541**
13542** SYNONYM SUPPORT
13543**
13544** Custom tokenizers may also support synonyms. Consider a case in which a
13545** user wishes to query for a phrase such as "first place". Using the
13546** built-in tokenizers, the FTS5 query 'first + place' will match instances
13547** of "first place" within the document set, but not alternative forms
13548** such as "1st place". In some applications, it would be better to match
13549** all instances of "first place" or "1st place" regardless of which form
13550** the user specified in the MATCH query text.
13551**
13552** There are several ways to approach this in FTS5:
13553**
13554** <ol><li> By mapping all synonyms to a single token. In this case, using
13555** the above example, this means that the tokenizer returns the
13556** same token for inputs "first" and "1st". Say that token is in
13557** fact "first", so that when the user inserts the document "I won
13558** 1st place" entries are added to the index for tokens "i", "won",
13559** "first" and "place". If the user then queries for '1st + place',
13560** the tokenizer substitutes "first" for "1st" and the query works
13561** as expected.
13562**
13563** <li> By querying the index for all synonyms of each query term
13564** separately. In this case, when tokenizing query text, the
13565** tokenizer may provide multiple synonyms for a single term
13566** within the document. FTS5 then queries the index for each
13567** synonym individually. For example, faced with the query:
13568**
13569** <codeblock>
13570** ... MATCH 'first place'</codeblock>
13571**
13572** the tokenizer offers both "1st" and "first" as synonyms for the
13573** first token in the MATCH query and FTS5 effectively runs a query
13574** similar to:
13575**
13576** <codeblock>
13577** ... MATCH '(first OR 1st) place'</codeblock>
13578**
13579** except that, for the purposes of auxiliary functions, the query
13580** still appears to contain just two phrases - "(first OR 1st)"
13581** being treated as a single phrase.
13582**
13583** <li> By adding multiple synonyms for a single term to the FTS index.
13584** Using this method, when tokenizing document text, the tokenizer
13585** provides multiple synonyms for each token. So that when a
13586** document such as "I won first place" is tokenized, entries are
13587** added to the FTS index for "i", "won", "first", "1st" and
13588** "place".
13589**
13590** This way, even if the tokenizer does not provide synonyms
13591** when tokenizing query text (it should not - to do so would be
13592** inefficient), it doesn't matter if the user queries for
13593** 'first + place' or '1st + place', as there are entries in the
13594** FTS index corresponding to both forms of the first token.
13595** </ol>
13596**
13597** Whether it is parsing document or query text, any call to xToken that
13598** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit
13599** is considered to supply a synonym for the previous token. For example,
13600** when parsing the document "I won first place", a tokenizer that supports
13601** synonyms would call xToken() 5 times, as follows:
13602**
13603** <codeblock>
13604** xToken(pCtx, 0, "i", 1, 0, 1);
13605** xToken(pCtx, 0, "won", 3, 2, 5);
13606** xToken(pCtx, 0, "first", 5, 6, 11);
13607** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11);
13608** xToken(pCtx, 0, "place", 5, 12, 17);
13609**</codeblock>
13610**
13611** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time
13612** xToken() is called. Multiple synonyms may be specified for a single token
13613** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence.
13614** There is no limit to the number of synonyms that may be provided for a
13615** single token.
13616**
13617** In many cases, method (1) above is the best approach. It does not add
13618** extra data to the FTS index or require FTS5 to query for multiple terms,
13619** so it is efficient in terms of disk space and query speed. However, it
13620** does not support prefix queries very well. If, as suggested above, the
13621** token "first" is substituted for "1st" by the tokenizer, then the query:
13622**
13623** <codeblock>
13624** ... MATCH '1s*'</codeblock>
13625**
13626** will not match documents that contain the token "1st" (as the tokenizer
13627** will probably not map "1s" to any prefix of "first").
13628**
13629** For full prefix support, method (3) may be preferred. In this case,
13630** because the index contains entries for both "first" and "1st", prefix
13631** queries such as 'fi*' or '1s*' will match correctly. However, because
13632** extra entries are added to the FTS index, this method uses more space
13633** within the database.
13634**
13635** Method (2) offers a midpoint between (1) and (3). Using this method,
13636** a query such as '1s*' will match documents that contain the literal
13637** token "1st", but not "first" (assuming the tokenizer is not able to
13638** provide synonyms for prefixes). However, a non-prefix query like '1st'
13639** will match against "1st" and "first". This method does not require
13640** extra disk space, as no extra entries are added to the FTS index.
13641** On the other hand, it may require more CPU cycles to run MATCH queries,
13642** as separate queries of the FTS index are required for each synonym.
13643**
13644** When using methods (2) or (3), it is important that the tokenizer only
13645** provide synonyms when tokenizing document text (method (3)) or query
13646** text (method (2)), not both. Doing so will not cause any errors, but is
13647** inefficient.
13648*/
13649typedef struct Fts5Tokenizer Fts5Tokenizer;
13650typedef struct fts5_tokenizer_v2 fts5_tokenizer_v2;
13651struct fts5_tokenizer_v2 {
13652 int iVersion; /* Currently always 2 */
13653
13654 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
13655 void (*xDelete)(Fts5Tokenizer*);
13656 int (*xTokenize)(Fts5Tokenizer*,
13657 void *pCtx,
13658 int flags, /* Mask of FTS5_TOKENIZE_* flags */
13659 const char *pText, int nText,
13660 const char *pLocale, int nLocale,
13661 int (*xToken)(
13662 void *pCtx, /* Copy of 2nd argument to xTokenize() */
13663 int tflags, /* Mask of FTS5_TOKEN_* flags */
13664 const char *pToken, /* Pointer to buffer containing token */
13665 int nToken, /* Size of token in bytes */
13666 int iStart, /* Byte offset of token within input text */
13667 int iEnd /* Byte offset of end of token within input text */
13668 )
13669 );
13670};
13671
13672/*
13673** New code should use the fts5_tokenizer_v2 type to define tokenizer
13674** implementations. The following type is included for legacy applications
13675** that still use it.
13676*/
13677typedef struct fts5_tokenizer fts5_tokenizer;
13678struct fts5_tokenizer {
13679 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
13680 void (*xDelete)(Fts5Tokenizer*);
13681 int (*xTokenize)(Fts5Tokenizer*,
13682 void *pCtx,
13683 int flags, /* Mask of FTS5_TOKENIZE_* flags */
13684 const char *pText, int nText,
13685 int (*xToken)(
13686 void *pCtx, /* Copy of 2nd argument to xTokenize() */
13687 int tflags, /* Mask of FTS5_TOKEN_* flags */
13688 const char *pToken, /* Pointer to buffer containing token */
13689 int nToken, /* Size of token in bytes */
13690 int iStart, /* Byte offset of token within input text */
13691 int iEnd /* Byte offset of end of token within input text */
13692 )
13693 );
13694};
13695
13696
13697/* Flags that may be passed as the third argument to xTokenize() */
13698#define FTS5_TOKENIZE_QUERY 0x0001
13699#define FTS5_TOKENIZE_PREFIX 0x0002
13700#define FTS5_TOKENIZE_DOCUMENT 0x0004
13701#define FTS5_TOKENIZE_AUX 0x0008
13702
13703/* Flags that may be passed by the tokenizer implementation back to FTS5
13704** as the third argument to the supplied xToken callback. */
13705#define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */
13706
13707/*
13708** END OF CUSTOM TOKENIZERS
13709*************************************************************************/
13710
13711/*************************************************************************
13712** FTS5 EXTENSION REGISTRATION API
13713*/
13714typedef struct fts5_api fts5_api;
13715struct fts5_api {
13716 int iVersion; /* Currently always set to 3 */
13717
13718 /* Create a new tokenizer */
13719 int (*xCreateTokenizer)(
13720 fts5_api *pApi,
13721 const char *zName,
13722 void *pUserData,
13723 fts5_tokenizer *pTokenizer,
13724 void (*xDestroy)(void*)
13725 );
13726
13727 /* Find an existing tokenizer */
13728 int (*xFindTokenizer)(
13729 fts5_api *pApi,
13730 const char *zName,
13731 void **ppUserData,
13732 fts5_tokenizer *pTokenizer
13733 );
13734
13735 /* Create a new auxiliary function */
13736 int (*xCreateFunction)(
13737 fts5_api *pApi,
13738 const char *zName,
13739 void *pUserData,
13740 fts5_extension_function xFunction,
13741 void (*xDestroy)(void*)
13742 );
13743
13744 /* APIs below this point are only available if iVersion>=3 */
13745
13746 /* Create a new tokenizer */
13747 int (*xCreateTokenizer_v2)(
13748 fts5_api *pApi,
13749 const char *zName,
13750 void *pUserData,
13751 fts5_tokenizer_v2 *pTokenizer,
13752 void (*xDestroy)(void*)
13753 );
13754
13755 /* Find an existing tokenizer */
13756 int (*xFindTokenizer_v2)(
13757 fts5_api *pApi,
13758 const char *zName,
13759 void **ppUserData,
13760 fts5_tokenizer_v2 **ppTokenizer
13761 );
13762};
13763
13764/*
13765** END OF REGISTRATION API
13766*************************************************************************/
13767
13768#ifdef __cplusplus
13769} /* end of the 'extern "C"' block */
13770#endif
13771
13772#endif /* _FTS5_H */
13773
13774/******** End of fts5.h *********/
13775#endif /* SQLITE3_H */