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** Provide the ability to override linkage features of the interface.
47*/
48#ifndef SQLITE_EXTERN
49# define SQLITE_EXTERN extern
50#endif
51#ifndef SQLITE_API
52# define SQLITE_API
53#endif
54#ifndef SQLITE_CDECL
55# define SQLITE_CDECL
56#endif
57#ifndef SQLITE_APICALL
58# define SQLITE_APICALL
59#endif
60#ifndef SQLITE_STDCALL
61# define SQLITE_STDCALL SQLITE_APICALL
62#endif
63#ifndef SQLITE_CALLBACK
64# define SQLITE_CALLBACK
65#endif
66#ifndef SQLITE_SYSAPI
67# define SQLITE_SYSAPI
68#endif
69
70/*
71** These no-op macros are used in front of interfaces to mark those
72** interfaces as either deprecated or experimental. New applications
73** should not use deprecated interfaces - they are supported for backwards
74** compatibility only. Application writers should be aware that
75** experimental interfaces are subject to change in point releases.
76**
77** These macros used to resolve to various kinds of compiler magic that
78** would generate warning messages when they were used. But that
79** compiler magic ended up generating such a flurry of bug reports
80** that we have taken it all out and gone back to using simple
81** noop macros.
82*/
83#define SQLITE_DEPRECATED
84#define SQLITE_EXPERIMENTAL
85
86/*
87** Ensure these symbols were not defined by some previous header file.
88*/
89#ifdef SQLITE_VERSION
90# undef SQLITE_VERSION
91#endif
92#ifdef SQLITE_VERSION_NUMBER
93# undef SQLITE_VERSION_NUMBER
94#endif
95
96/*
97** CAPI3REF: Compile-Time Library Version Numbers
98**
99** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header
100** evaluates to a string literal that is the SQLite version in the
101** format "X.Y.Z" where X is the major version number (always 3 for
102** SQLite3) and Y is the minor version number and Z is the release number.)^
103** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer
104** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same
105** numbers used in [SQLITE_VERSION].)^
106** The SQLITE_VERSION_NUMBER for any given release of SQLite will also
107** be larger than the release from which it is derived. Either Y will
108** be held constant and Z will be incremented or else Y will be incremented
109** and Z will be reset to zero.
110**
111** Since [version 3.6.18] ([dateof:3.6.18]),
112** SQLite source code has been stored in the
113** <a href="http://www.fossil-scm.org/">Fossil configuration management
114** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to
115** a string which identifies a particular check-in of SQLite
116** within its configuration management system. ^The SQLITE_SOURCE_ID
117** string contains the date and time of the check-in (UTC) and a SHA1
118** or SHA3-256 hash of the entire source tree. If the source code has
119** been edited in any way since it was last checked in, then the last
120** four hexadecimal digits of the hash may be modified.
121**
122** See also: [sqlite3_libversion()],
123** [sqlite3_libversion_number()], [sqlite3_sourceid()],
124** [sqlite_version()] and [sqlite_source_id()].
125*/
126#define SQLITE_VERSION "3.23.0"
127#define SQLITE_VERSION_NUMBER 3023000
128#define SQLITE_SOURCE_ID DUCKDB_SOURCE_ID
129
130
131/*
132** CAPI3REF: Run-Time Library Version Numbers
133** KEYWORDS: sqlite3_version sqlite3_sourceid
134**
135** These interfaces provide the same information as the [SQLITE_VERSION],
136** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
137** but are associated with the library instead of the header file. ^(Cautious
138** programmers might include assert() statements in their application to
139** verify that values returned by these interfaces match the macros in
140** the header, and thus ensure that the application is
141** compiled with matching library and header files.
142**
143** <blockquote><pre>
144** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
145** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 );
146** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
147** </pre></blockquote>)^
148**
149** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION]
150** macro. ^The sqlite3_libversion() function returns a pointer to the
151** to the sqlite3_version[] string constant. The sqlite3_libversion()
152** function is provided for use in DLLs since DLL users usually do not have
153** direct access to string constants within the DLL. ^The
154** sqlite3_libversion_number() function returns an integer equal to
155** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns
156** a pointer to a string constant whose value is the same as the
157** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built
158** using an edited copy of [the amalgamation], then the last four characters
159** of the hash might be different from [SQLITE_SOURCE_ID].)^
160**
161** See also: [sqlite_version()] and [sqlite_source_id()].
162*/
163SQLITE_API SQLITE_EXTERN const char sqlite3_version[];
164SQLITE_API const char *sqlite3_libversion(void);
165SQLITE_API const char *sqlite3_sourceid(void);
166SQLITE_API int sqlite3_libversion_number(void);
167
168/*
169** CAPI3REF: Run-Time Library Compilation Options Diagnostics
170**
171** ^The sqlite3_compileoption_used() function returns 0 or 1
172** indicating whether the specified option was defined at
173** compile time. ^The SQLITE_ prefix may be omitted from the
174** option name passed to sqlite3_compileoption_used().
175**
176** ^The sqlite3_compileoption_get() function allows iterating
177** over the list of options that were defined at compile time by
178** returning the N-th compile time option string. ^If N is out of range,
179** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_
180** prefix is omitted from any strings returned by
181** sqlite3_compileoption_get().
182**
183** ^Support for the diagnostic functions sqlite3_compileoption_used()
184** and sqlite3_compileoption_get() may be omitted by specifying the
185** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time.
186**
187** See also: SQL functions [sqlite_compileoption_used()] and
188** [sqlite_compileoption_get()] and the [compile_options pragma].
189*/
190#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
191SQLITE_API int sqlite3_compileoption_used(const char *zOptName);
192SQLITE_API const char *sqlite3_compileoption_get(int N);
193#endif
194
195/*
196** CAPI3REF: Test To See If The Library Is Threadsafe
197**
198** ^The sqlite3_threadsafe() function returns zero if and only if
199** SQLite was compiled with mutexing code omitted due to the
200** [SQLITE_THREADSAFE] compile-time option being set to 0.
201**
202** SQLite can be compiled with or without mutexes. When
203** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
204** are enabled and SQLite is threadsafe. When the
205** [SQLITE_THREADSAFE] macro is 0,
206** the mutexes are omitted. Without the mutexes, it is not safe
207** to use SQLite concurrently from more than one thread.
208**
209** Enabling mutexes incurs a measurable performance penalty.
210** So if speed is of utmost importance, it makes sense to disable
211** the mutexes. But for maximum safety, mutexes should be enabled.
212** ^The default behavior is for mutexes to be enabled.
213**
214** This interface can be used by an application to make sure that the
215** version of SQLite that it is linking against was compiled with
216** the desired setting of the [SQLITE_THREADSAFE] macro.
217**
218** This interface only reports on the compile-time mutex setting
219** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with
220** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
221** can be fully or partially disabled using a call to [sqlite3_config()]
222** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
223** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the
224** sqlite3_threadsafe() function shows only the compile-time setting of
225** thread safety, not any run-time changes to that setting made by
226** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
227** is unchanged by calls to sqlite3_config().)^
228**
229** See the [threading mode] documentation for additional information.
230*/
231SQLITE_API int sqlite3_threadsafe(void);
232
233/*
234** CAPI3REF: Database Connection Handle
235** KEYWORDS: {database connection} {database connections}
236**
237** Each open SQLite database is represented by a pointer to an instance of
238** the opaque structure named "sqlite3". It is useful to think of an sqlite3
239** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and
240** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
241** and [sqlite3_close_v2()] are its destructors. There are many other
242** interfaces (such as
243** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
244** [sqlite3_busy_timeout()] to name but three) that are methods on an
245** sqlite3 object.
246*/
247typedef struct sqlite3 sqlite3;
248
249/*
250** CAPI3REF: 64-Bit Integer Types
251** KEYWORDS: sqlite_int64 sqlite_uint64
252**
253** Because there is no cross-platform way to specify 64-bit integer types
254** SQLite includes typedefs for 64-bit signed and unsigned integers.
255**
256** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
257** The sqlite_int64 and sqlite_uint64 types are supported for backwards
258** compatibility only.
259**
260** ^The sqlite3_int64 and sqlite_int64 types can store integer values
261** between -9223372036854775808 and +9223372036854775807 inclusive. ^The
262** sqlite3_uint64 and sqlite_uint64 types can store integer values
263** between 0 and +18446744073709551615 inclusive.
264*/
265#ifdef SQLITE_INT64_TYPE
266 typedef SQLITE_INT64_TYPE sqlite_int64;
267# ifdef SQLITE_UINT64_TYPE
268 typedef SQLITE_UINT64_TYPE sqlite_uint64;
269# else
270 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
271# endif
272#elif defined(_MSC_VER) || defined(__BORLANDC__)
273 typedef __int64 sqlite_int64;
274 typedef unsigned __int64 sqlite_uint64;
275#else
276 typedef long long int sqlite_int64;
277 typedef unsigned long long int sqlite_uint64;
278#endif
279typedef sqlite_int64 sqlite3_int64;
280typedef sqlite_uint64 sqlite3_uint64;
281
282/*
283** If compiling for a processor that lacks floating point support,
284** substitute integer for floating-point.
285*/
286#ifdef SQLITE_OMIT_FLOATING_POINT
287# define double sqlite3_int64
288#endif
289
290/*
291** CAPI3REF: Closing A Database Connection
292** DESTRUCTOR: sqlite3
293**
294** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors
295** for the [sqlite3] object.
296** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if
297** the [sqlite3] object is successfully destroyed and all associated
298** resources are deallocated.
299**
300** ^If the database connection is associated with unfinalized prepared
301** statements or unfinished sqlite3_backup objects then sqlite3_close()
302** will leave the database connection open and return [SQLITE_BUSY].
303** ^If sqlite3_close_v2() is called with unfinalized prepared statements
304** and/or unfinished sqlite3_backups, then the database connection becomes
305** an unusable "zombie" which will automatically be deallocated when the
306** last prepared statement is finalized or the last sqlite3_backup is
307** finished. The sqlite3_close_v2() interface is intended for use with
308** host languages that are garbage collected, and where the order in which
309** destructors are called is arbitrary.
310**
311** Applications should [sqlite3_finalize | finalize] all [prepared statements],
312** [sqlite3_blob_close | close] all [BLOB handles], and
313** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated
314** with the [sqlite3] object prior to attempting to close the object. ^If
315** sqlite3_close_v2() is called on a [database connection] that still has
316** outstanding [prepared statements], [BLOB handles], and/or
317** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation
318** of resources is deferred until all [prepared statements], [BLOB handles],
319** and [sqlite3_backup] objects are also destroyed.
320**
321** ^If an [sqlite3] object is destroyed while a transaction is open,
322** the transaction is automatically rolled back.
323**
324** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)]
325** must be either a NULL
326** pointer or an [sqlite3] object pointer obtained
327** from [sqlite3_open()], [sqlite3_open16()], or
328** [sqlite3_open_v2()], and not previously closed.
329** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer
330** argument is a harmless no-op.
331*/
332SQLITE_API int sqlite3_close(sqlite3*);
333SQLITE_API int sqlite3_close_v2(sqlite3*);
334
335/*
336** The type for a callback function.
337** This is legacy and deprecated. It is included for historical
338** compatibility and is not documented.
339*/
340typedef int (*sqlite3_callback)(void*,int,char**, char**);
341
342/*
343** CAPI3REF: One-Step Query Execution Interface
344** METHOD: sqlite3
345**
346** The sqlite3_exec() interface is a convenience wrapper around
347** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
348** that allows an application to run multiple statements of SQL
349** without having to use a lot of C code.
350**
351** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
352** semicolon-separate SQL statements passed into its 2nd argument,
353** in the context of the [database connection] passed in as its 1st
354** argument. ^If the callback function of the 3rd argument to
355** sqlite3_exec() is not NULL, then it is invoked for each result row
356** coming out of the evaluated SQL statements. ^The 4th argument to
357** sqlite3_exec() is relayed through to the 1st argument of each
358** callback invocation. ^If the callback pointer to sqlite3_exec()
359** is NULL, then no callback is ever invoked and result rows are
360** ignored.
361**
362** ^If an error occurs while evaluating the SQL statements passed into
363** sqlite3_exec(), then execution of the current statement stops and
364** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec()
365** is not NULL then any error message is written into memory obtained
366** from [sqlite3_malloc()] and passed back through the 5th parameter.
367** To avoid memory leaks, the application should invoke [sqlite3_free()]
368** on error message strings returned through the 5th parameter of
369** sqlite3_exec() after the error message string is no longer needed.
370** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
371** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
372** NULL before returning.
373**
374** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
375** routine returns SQLITE_ABORT without invoking the callback again and
376** without running any subsequent SQL statements.
377**
378** ^The 2nd argument to the sqlite3_exec() callback function is the
379** number of columns in the result. ^The 3rd argument to the sqlite3_exec()
380** callback is an array of pointers to strings obtained as if from
381** [sqlite3_column_text()], one for each column. ^If an element of a
382** result row is NULL then the corresponding string pointer for the
383** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the
384** sqlite3_exec() callback is an array of pointers to strings where each
385** entry represents the name of corresponding result column as obtained
386** from [sqlite3_column_name()].
387**
388** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
389** to an empty string, or a pointer that contains only whitespace and/or
390** SQL comments, then no SQL statements are evaluated and the database
391** is not changed.
392**
393** Restrictions:
394**
395** <ul>
396** <li> The application must ensure that the 1st parameter to sqlite3_exec()
397** is a valid and open [database connection].
398** <li> The application must not close the [database connection] specified by
399** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
400** <li> The application must not modify the SQL statement text passed into
401** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
402** </ul>
403*/
404SQLITE_API int sqlite3_exec(
405 sqlite3*, /* An open database */
406 const char *sql, /* SQL to be evaluated */
407 int (*callback)(void*,int,char**,char**), /* Callback function */
408 void *, /* 1st argument to callback */
409 char **errmsg /* Error msg written here */
410);
411
412/*
413** CAPI3REF: Result Codes
414** KEYWORDS: {result code definitions}
415**
416** Many SQLite functions return an integer result code from the set shown
417** here in order to indicate success or failure.
418**
419** New error codes may be added in future versions of SQLite.
420**
421** See also: [extended result code definitions]
422*/
423#define SQLITE_OK 0 /* Successful result */
424/* beginning-of-error-codes */
425#define SQLITE_ERROR 1 /* Generic error */
426#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */
427#define SQLITE_PERM 3 /* Access permission denied */
428#define SQLITE_ABORT 4 /* Callback routine requested an abort */
429#define SQLITE_BUSY 5 /* The database file is locked */
430#define SQLITE_LOCKED 6 /* A table in the database is locked */
431#define SQLITE_NOMEM 7 /* A malloc() failed */
432#define SQLITE_READONLY 8 /* Attempt to write a readonly database */
433#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/
434#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */
435#define SQLITE_CORRUPT 11 /* The database disk image is malformed */
436#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */
437#define SQLITE_FULL 13 /* Insertion failed because database is full */
438#define SQLITE_CANTOPEN 14 /* Unable to open the database file */
439#define SQLITE_PROTOCOL 15 /* Database lock protocol error */
440#define SQLITE_EMPTY 16 /* Internal use only */
441#define SQLITE_SCHEMA 17 /* The database schema changed */
442#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */
443#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */
444#define SQLITE_MISMATCH 20 /* Data type mismatch */
445#define SQLITE_MISUSE 21 /* Library used incorrectly */
446#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */
447#define SQLITE_AUTH 23 /* Authorization denied */
448#define SQLITE_FORMAT 24 /* Not used */
449#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */
450#define SQLITE_NOTADB 26 /* File opened that is not a database file */
451#define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */
452#define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */
453#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */
454#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */
455/* end-of-error-codes */
456
457/*
458** CAPI3REF: Extended Result Codes
459** KEYWORDS: {extended result code definitions}
460**
461** In its default configuration, SQLite API routines return one of 30 integer
462** [result codes]. However, experience has shown that many of
463** these result codes are too coarse-grained. They do not provide as
464** much information about problems as programmers might like. In an effort to
465** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8]
466** and later) include
467** support for additional result codes that provide more detailed information
468** about errors. These [extended result codes] are enabled or disabled
469** on a per database connection basis using the
470** [sqlite3_extended_result_codes()] API. Or, the extended code for
471** the most recent error can be obtained using
472** [sqlite3_extended_errcode()].
473*/
474#define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8))
475#define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8))
476#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8))
477#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8))
478#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8))
479#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8))
480#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8))
481#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8))
482#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8))
483#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8))
484#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8))
485#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8))
486#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8))
487#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8))
488#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8))
489#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))
490#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8))
491#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8))
492#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8))
493#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8))
494#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8))
495#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8))
496#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8))
497#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8))
498#define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8))
499#define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8))
500#define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8))
501#define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8))
502#define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8))
503#define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8))
504#define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8))
505#define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8))
506#define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8))
507#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8))
508#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8))
509#define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8))
510#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8))
511#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8))
512#define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8))
513#define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8))
514#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8))
515#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8))
516#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8))
517#define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8))
518#define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8))
519#define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8))
520#define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8))
521#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8))
522#define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8))
523#define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8))
524#define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8))
525#define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8))
526#define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8))
527#define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8))
528#define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8))
529#define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8))
530#define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8))
531#define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8))
532#define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8))
533#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8))
534#define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8))
535#define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8))
536#define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8))
537
538/*
539** CAPI3REF: Flags For File Open Operations
540**
541** These bit values are intended for use in the
542** 3rd parameter to the [sqlite3_open_v2()] interface and
543** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
544*/
545#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */
546#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */
547#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */
548#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */
549#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */
550#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */
551#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */
552#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */
553#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */
554#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */
555#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */
556#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */
557#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */
558#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */
559#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */
560#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */
561#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */
562#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */
563#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */
564#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */
565
566/* Reserved: 0x00F00000 */
567
568/*
569** CAPI3REF: Device Characteristics
570**
571** The xDeviceCharacteristics method of the [sqlite3_io_methods]
572** object returns an integer which is a vector of these
573** bit values expressing I/O characteristics of the mass storage
574** device that holds the file that the [sqlite3_io_methods]
575** refers to.
576**
577** The SQLITE_IOCAP_ATOMIC property means that all writes of
578** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
579** mean that writes of blocks that are nnn bytes in size and
580** are aligned to an address which is an integer multiple of
581** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
582** that when data is appended to a file, the data is appended
583** first then the size of the file is extended, never the other
584** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
585** information is written to disk in the same order as calls
586** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that
587** after reboot following a crash or power loss, the only bytes in a
588** file that were written at the application level might have changed
589** and that adjacent bytes, even bytes within the same sector are
590** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN
591** flag indicates that a file cannot be deleted when open. The
592** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on
593** read-only media and cannot be changed even by processes with
594** elevated privileges.
595**
596** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying
597** filesystem supports doing multiple write operations atomically when those
598** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and
599** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE].
600*/
601#define SQLITE_IOCAP_ATOMIC 0x00000001
602#define SQLITE_IOCAP_ATOMIC512 0x00000002
603#define SQLITE_IOCAP_ATOMIC1K 0x00000004
604#define SQLITE_IOCAP_ATOMIC2K 0x00000008
605#define SQLITE_IOCAP_ATOMIC4K 0x00000010
606#define SQLITE_IOCAP_ATOMIC8K 0x00000020
607#define SQLITE_IOCAP_ATOMIC16K 0x00000040
608#define SQLITE_IOCAP_ATOMIC32K 0x00000080
609#define SQLITE_IOCAP_ATOMIC64K 0x00000100
610#define SQLITE_IOCAP_SAFE_APPEND 0x00000200
611#define SQLITE_IOCAP_SEQUENTIAL 0x00000400
612#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800
613#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000
614#define SQLITE_IOCAP_IMMUTABLE 0x00002000
615#define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000
616
617/*
618** CAPI3REF: File Locking Levels
619**
620** SQLite uses one of these integer values as the second
621** argument to calls it makes to the xLock() and xUnlock() methods
622** of an [sqlite3_io_methods] object.
623*/
624#define SQLITE_LOCK_NONE 0
625#define SQLITE_LOCK_SHARED 1
626#define SQLITE_LOCK_RESERVED 2
627#define SQLITE_LOCK_PENDING 3
628#define SQLITE_LOCK_EXCLUSIVE 4
629
630/*
631** CAPI3REF: Synchronization Type Flags
632**
633** When SQLite invokes the xSync() method of an
634** [sqlite3_io_methods] object it uses a combination of
635** these integer values as the second argument.
636**
637** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
638** sync operation only needs to flush data to mass storage. Inode
639** information need not be flushed. If the lower four bits of the flag
640** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.
641** If the lower four bits equal SQLITE_SYNC_FULL, that means
642** to use Mac OS X style fullsync instead of fsync().
643**
644** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags
645** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL
646** settings. The [synchronous pragma] determines when calls to the
647** xSync VFS method occur and applies uniformly across all platforms.
648** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how
649** energetic or rigorous or forceful the sync operations are and
650** only make a difference on Mac OSX for the default SQLite code.
651** (Third-party VFS implementations might also make the distinction
652** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the
653** operating systems natively supported by SQLite, only Mac OSX
654** cares about the difference.)
655*/
656#define SQLITE_SYNC_NORMAL 0x00002
657#define SQLITE_SYNC_FULL 0x00003
658#define SQLITE_SYNC_DATAONLY 0x00010
659
660/*
661** CAPI3REF: OS Interface Open File Handle
662**
663** An [sqlite3_file] object represents an open file in the
664** [sqlite3_vfs | OS interface layer]. Individual OS interface
665** implementations will
666** want to subclass this object by appending additional fields
667** for their own use. The pMethods entry is a pointer to an
668** [sqlite3_io_methods] object that defines methods for performing
669** I/O operations on the open file.
670*/
671typedef struct sqlite3_file sqlite3_file;
672struct sqlite3_file {
673 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */
674};
675
676/*
677** CAPI3REF: OS Interface File Virtual Methods Object
678**
679** Every file opened by the [sqlite3_vfs.xOpen] method populates an
680** [sqlite3_file] object (or, more commonly, a subclass of the
681** [sqlite3_file] object) with a pointer to an instance of this object.
682** This object defines the methods used to perform various operations
683** against the open file represented by the [sqlite3_file] object.
684**
685** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element
686** to a non-NULL pointer, then the sqlite3_io_methods.xClose method
687** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The
688** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen]
689** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element
690** to NULL.
691**
692** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
693** [SQLITE_SYNC_FULL]. The first choice is the normal fsync().
694** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY]
695** flag may be ORed in to indicate that only the data of the file
696** and not its inode needs to be synced.
697**
698** The integer values to xLock() and xUnlock() are one of
699** <ul>
700** <li> [SQLITE_LOCK_NONE],
701** <li> [SQLITE_LOCK_SHARED],
702** <li> [SQLITE_LOCK_RESERVED],
703** <li> [SQLITE_LOCK_PENDING], or
704** <li> [SQLITE_LOCK_EXCLUSIVE].
705** </ul>
706** xLock() increases the lock. xUnlock() decreases the lock.
707** The xCheckReservedLock() method checks whether any database connection,
708** either in this process or in some other process, is holding a RESERVED,
709** PENDING, or EXCLUSIVE lock on the file. It returns true
710** if such a lock exists and false otherwise.
711**
712** The xFileControl() method is a generic interface that allows custom
713** VFS implementations to directly control an open file using the
714** [sqlite3_file_control()] interface. The second "op" argument is an
715** integer opcode. The third argument is a generic pointer intended to
716** point to a structure that may contain arguments or space in which to
717** write return values. Potential uses for xFileControl() might be
718** functions to enable blocking locks with timeouts, to change the
719** locking strategy (for example to use dot-file locks), to inquire
720** about the status of a lock, or to break stale locks. The SQLite
721** core reserves all opcodes less than 100 for its own use.
722** A [file control opcodes | list of opcodes] less than 100 is available.
723** Applications that define a custom xFileControl method should use opcodes
724** greater than 100 to avoid conflicts. VFS implementations should
725** return [SQLITE_NOTFOUND] for file control opcodes that they do not
726** recognize.
727**
728** The xSectorSize() method returns the sector size of the
729** device that underlies the file. The sector size is the
730** minimum write that can be performed without disturbing
731** other bytes in the file. The xDeviceCharacteristics()
732** method returns a bit vector describing behaviors of the
733** underlying device:
734**
735** <ul>
736** <li> [SQLITE_IOCAP_ATOMIC]
737** <li> [SQLITE_IOCAP_ATOMIC512]
738** <li> [SQLITE_IOCAP_ATOMIC1K]
739** <li> [SQLITE_IOCAP_ATOMIC2K]
740** <li> [SQLITE_IOCAP_ATOMIC4K]
741** <li> [SQLITE_IOCAP_ATOMIC8K]
742** <li> [SQLITE_IOCAP_ATOMIC16K]
743** <li> [SQLITE_IOCAP_ATOMIC32K]
744** <li> [SQLITE_IOCAP_ATOMIC64K]
745** <li> [SQLITE_IOCAP_SAFE_APPEND]
746** <li> [SQLITE_IOCAP_SEQUENTIAL]
747** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN]
748** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE]
749** <li> [SQLITE_IOCAP_IMMUTABLE]
750** <li> [SQLITE_IOCAP_BATCH_ATOMIC]
751** </ul>
752**
753** The SQLITE_IOCAP_ATOMIC property means that all writes of
754** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
755** mean that writes of blocks that are nnn bytes in size and
756** are aligned to an address which is an integer multiple of
757** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
758** that when data is appended to a file, the data is appended
759** first then the size of the file is extended, never the other
760** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
761** information is written to disk in the same order as calls
762** to xWrite().
763**
764** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
765** in the unread portions of the buffer with zeros. A VFS that
766** fails to zero-fill short reads might seem to work. However,
767** failure to zero-fill short reads will eventually lead to
768** database corruption.
769*/
770typedef struct sqlite3_io_methods sqlite3_io_methods;
771struct sqlite3_io_methods {
772 int iVersion;
773 int (*xClose)(sqlite3_file*);
774 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
775 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
776 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
777 int (*xSync)(sqlite3_file*, int flags);
778 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
779 int (*xLock)(sqlite3_file*, int);
780 int (*xUnlock)(sqlite3_file*, int);
781 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);
782 int (*xFileControl)(sqlite3_file*, int op, void *pArg);
783 int (*xSectorSize)(sqlite3_file*);
784 int (*xDeviceCharacteristics)(sqlite3_file*);
785 /* Methods above are valid for version 1 */
786 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
787 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags);
788 void (*xShmBarrier)(sqlite3_file*);
789 int (*xShmUnmap)(sqlite3_file*, int deleteFlag);
790 /* Methods above are valid for version 2 */
791 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp);
792 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p);
793 /* Methods above are valid for version 3 */
794 /* Additional methods may be added in future releases */
795};
796
797/*
798** CAPI3REF: Standard File Control Opcodes
799** KEYWORDS: {file control opcodes} {file control opcode}
800**
801** These integer constants are opcodes for the xFileControl method
802** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
803** interface.
804**
805** <ul>
806** <li>[[SQLITE_FCNTL_LOCKSTATE]]
807** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This
808** opcode causes the xFileControl method to write the current state of
809** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
810** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
811** into an integer that the pArg argument points to. This capability
812** is used during testing and is only available when the SQLITE_TEST
813** compile-time option is used.
814**
815** <li>[[SQLITE_FCNTL_SIZE_HINT]]
816** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
817** layer a hint of how large the database file will grow to be during the
818** current transaction. This hint is not guaranteed to be accurate but it
819** is often close. The underlying VFS might choose to preallocate database
820** file space based on this hint in order to help writes to the database
821** file run faster.
822**
823** <li>[[SQLITE_FCNTL_CHUNK_SIZE]]
824** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
825** extends and truncates the database file in chunks of a size specified
826** by the user. The fourth argument to [sqlite3_file_control()] should
827** point to an integer (type int) containing the new chunk-size to use
828** for the nominated database. Allocating database file space in large
829** chunks (say 1MB at a time), may reduce file-system fragmentation and
830** improve performance on some systems.
831**
832** <li>[[SQLITE_FCNTL_FILE_POINTER]]
833** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
834** to the [sqlite3_file] object associated with a particular database
835** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER].
836**
837** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]]
838** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer
839** to the [sqlite3_file] object associated with the journal file (either
840** the [rollback journal] or the [write-ahead log]) for a particular database
841** connection. See also [SQLITE_FCNTL_FILE_POINTER].
842**
843** <li>[[SQLITE_FCNTL_SYNC_OMITTED]]
844** No longer in use.
845**
846** <li>[[SQLITE_FCNTL_SYNC]]
847** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and
848** sent to the VFS immediately before the xSync method is invoked on a
849** database file descriptor. Or, if the xSync method is not invoked
850** because the user has configured SQLite with
851** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place
852** of the xSync method. In most cases, the pointer argument passed with
853** this file-control is NULL. However, if the database file is being synced
854** as part of a multi-database commit, the argument points to a nul-terminated
855** string containing the transactions master-journal file name. VFSes that
856** do not need this signal should silently ignore this opcode. Applications
857** should not call [sqlite3_file_control()] with this opcode as doing so may
858** disrupt the operation of the specialized VFSes that do require it.
859**
860** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]]
861** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite
862** and sent to the VFS after a transaction has been committed immediately
863** but before the database is unlocked. VFSes that do not need this signal
864** should silently ignore this opcode. Applications should not call
865** [sqlite3_file_control()] with this opcode as doing so may disrupt the
866** operation of the specialized VFSes that do require it.
867**
868** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]]
869** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
870** retry counts and intervals for certain disk I/O operations for the
871** windows [VFS] in order to provide robustness in the presence of
872** anti-virus programs. By default, the windows VFS will retry file read,
873** file write, and file delete operations up to 10 times, with a delay
874** of 25 milliseconds before the first retry and with the delay increasing
875** by an additional 25 milliseconds with each subsequent retry. This
876** opcode allows these two values (10 retries and 25 milliseconds of delay)
877** to be adjusted. The values are changed for all database connections
878** within the same process. The argument is a pointer to an array of two
879** integers where the first integer is the new retry count and the second
880** integer is the delay. If either integer is negative, then the setting
881** is not changed but instead the prior value of that setting is written
882** into the array entry, allowing the current retry settings to be
883** interrogated. The zDbName parameter is ignored.
884**
885** <li>[[SQLITE_FCNTL_PERSIST_WAL]]
886** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
887** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary
888** write ahead log and shared memory files used for transaction control
889** are automatically deleted when the latest connection to the database
890** closes. Setting persistent WAL mode causes those files to persist after
891** close. Persisting the files is useful when other processes that do not
892** have write permission on the directory containing the database file want
893** to read the database file, as the WAL and shared memory files must exist
894** in order for the database to be readable. The fourth parameter to
895** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
896** That integer is 0 to disable persistent WAL mode or 1 to enable persistent
897** WAL mode. If the integer is -1, then it is overwritten with the current
898** WAL persistence setting.
899**
900** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]]
901** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the
902** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting
903** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the
904** xDeviceCharacteristics methods. The fourth parameter to
905** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
906** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage
907** mode. If the integer is -1, then it is overwritten with the current
908** zero-damage mode setting.
909**
910** <li>[[SQLITE_FCNTL_OVERWRITE]]
911** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
912** a write transaction to indicate that, unless it is rolled back for some
913** reason, the entire database file will be overwritten by the current
914** transaction. This is used by VACUUM operations.
915**
916** <li>[[SQLITE_FCNTL_VFSNAME]]
917** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of
918** all [VFSes] in the VFS stack. The names are of all VFS shims and the
919** final bottom-level VFS are written into memory obtained from
920** [sqlite3_malloc()] and the result is stored in the char* variable
921** that the fourth parameter of [sqlite3_file_control()] points to.
922** The caller is responsible for freeing the memory when done. As with
923** all file-control actions, there is no guarantee that this will actually
924** do anything. Callers should initialize the char* variable to a NULL
925** pointer in case this file-control is not implemented. This file-control
926** is intended for diagnostic use only.
927**
928** <li>[[SQLITE_FCNTL_VFS_POINTER]]
929** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level
930** [VFSes] currently in use. ^(The argument X in
931** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be
932** of type "[sqlite3_vfs] **". This opcodes will set *X
933** to a pointer to the top-level VFS.)^
934** ^When there are multiple VFS shims in the stack, this opcode finds the
935** upper-most shim only.
936**
937** <li>[[SQLITE_FCNTL_PRAGMA]]
938** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA]
939** file control is sent to the open [sqlite3_file] object corresponding
940** to the database file to which the pragma statement refers. ^The argument
941** to the [SQLITE_FCNTL_PRAGMA] file control is an array of
942** pointers to strings (char**) in which the second element of the array
943** is the name of the pragma and the third element is the argument to the
944** pragma or NULL if the pragma has no argument. ^The handler for an
945** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element
946** of the char** argument point to a string obtained from [sqlite3_mprintf()]
947** or the equivalent and that string will become the result of the pragma or
948** the error message if the pragma fails. ^If the
949** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal
950** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA]
951** file control returns [SQLITE_OK], then the parser assumes that the
952** VFS has handled the PRAGMA itself and the parser generates a no-op
953** prepared statement if result string is NULL, or that returns a copy
954** of the result string if the string is non-NULL.
955** ^If the [SQLITE_FCNTL_PRAGMA] file control returns
956** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
957** that the VFS encountered an error while handling the [PRAGMA] and the
958** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA]
959** file control occurs at the beginning of pragma statement analysis and so
960** it is able to override built-in [PRAGMA] statements.
961**
962** <li>[[SQLITE_FCNTL_BUSYHANDLER]]
963** ^The [SQLITE_FCNTL_BUSYHANDLER]
964** file-control may be invoked by SQLite on the database file handle
965** shortly after it is opened in order to provide a custom VFS with access
966** to the connections busy-handler callback. The argument is of type (void **)
967** - an array of two (void *) values. The first (void *) actually points
968** to a function of type (int (*)(void *)). In order to invoke the connections
969** busy-handler, this function should be invoked with the second (void *) in
970** the array as the only argument. If it returns non-zero, then the operation
971** should be retried. If it returns zero, the custom VFS should abandon the
972** current operation.
973**
974** <li>[[SQLITE_FCNTL_TEMPFILENAME]]
975** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control
976** to have SQLite generate a
977** temporary filename using the same algorithm that is followed to generate
978** temporary filenames for TEMP tables and other internal uses. The
979** argument should be a char** which will be filled with the filename
980** written into memory obtained from [sqlite3_malloc()]. The caller should
981** invoke [sqlite3_free()] on the result to avoid a memory leak.
982**
983** <li>[[SQLITE_FCNTL_MMAP_SIZE]]
984** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the
985** maximum number of bytes that will be used for memory-mapped I/O.
986** The argument is a pointer to a value of type sqlite3_int64 that
987** is an advisory maximum number of bytes in the file to memory map. The
988** pointer is overwritten with the old value. The limit is not changed if
989** the value originally pointed to is negative, and so the current limit
990** can be queried by passing in a pointer to a negative number. This
991** file-control is used internally to implement [PRAGMA mmap_size].
992**
993** <li>[[SQLITE_FCNTL_TRACE]]
994** The [SQLITE_FCNTL_TRACE] file control provides advisory information
995** to the VFS about what the higher layers of the SQLite stack are doing.
996** This file control is used by some VFS activity tracing [shims].
997** The argument is a zero-terminated string. Higher layers in the
998** SQLite stack may generate instances of this file control if
999** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled.
1000**
1001** <li>[[SQLITE_FCNTL_HAS_MOVED]]
1002** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a
1003** pointer to an integer and it writes a boolean into that integer depending
1004** on whether or not the file has been renamed, moved, or deleted since it
1005** was first opened.
1006**
1007** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]]
1008** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the
1009** underlying native file handle associated with a file handle. This file
1010** control interprets its argument as a pointer to a native file handle and
1011** writes the resulting value there.
1012**
1013** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]]
1014** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This
1015** opcode causes the xFileControl method to swap the file handle with the one
1016** pointed to by the pArg argument. This capability is used during testing
1017** and only needs to be supported when SQLITE_TEST is defined.
1018**
1019** <li>[[SQLITE_FCNTL_WAL_BLOCK]]
1020** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might
1021** be advantageous to block on the next WAL lock if the lock is not immediately
1022** available. The WAL subsystem issues this signal during rare
1023** circumstances in order to fix a problem with priority inversion.
1024** Applications should <em>not</em> use this file-control.
1025**
1026** <li>[[SQLITE_FCNTL_ZIPVFS]]
1027** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other
1028** VFS should return SQLITE_NOTFOUND for this opcode.
1029**
1030** <li>[[SQLITE_FCNTL_RBU]]
1031** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by
1032** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for
1033** this opcode.
1034**
1035** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]]
1036** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then
1037** the file descriptor is placed in "batch write mode", which
1038** means all subsequent write operations will be deferred and done
1039** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems
1040** that do not support batch atomic writes will return SQLITE_NOTFOUND.
1041** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to
1042** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or
1043** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make
1044** no VFS interface calls on the same [sqlite3_file] file descriptor
1045** except for calls to the xWrite method and the xFileControl method
1046** with [SQLITE_FCNTL_SIZE_HINT].
1047**
1048** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]]
1049** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write
1050** operations since the previous successful call to
1051** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically.
1052** This file control returns [SQLITE_OK] if and only if the writes were
1053** all performed successfully and have been committed to persistent storage.
1054** ^Regardless of whether or not it is successful, this file control takes
1055** the file descriptor out of batch write mode so that all subsequent
1056** write operations are independent.
1057** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without
1058** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1059**
1060** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]]
1061** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write
1062** operations since the previous successful call to
1063** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back.
1064** ^This file control takes the file descriptor out of batch write mode
1065** so that all subsequent write operations are independent.
1066** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without
1067** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1068**
1069** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]]
1070** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode causes attempts to obtain
1071** a file lock using the xLock or xShmLock methods of the VFS to wait
1072** for up to M milliseconds before failing, where M is the single
1073** unsigned integer parameter.
1074** </ul>
1075*/
1076#define SQLITE_FCNTL_LOCKSTATE 1
1077#define SQLITE_FCNTL_GET_LOCKPROXYFILE 2
1078#define SQLITE_FCNTL_SET_LOCKPROXYFILE 3
1079#define SQLITE_FCNTL_LAST_ERRNO 4
1080#define SQLITE_FCNTL_SIZE_HINT 5
1081#define SQLITE_FCNTL_CHUNK_SIZE 6
1082#define SQLITE_FCNTL_FILE_POINTER 7
1083#define SQLITE_FCNTL_SYNC_OMITTED 8
1084#define SQLITE_FCNTL_WIN32_AV_RETRY 9
1085#define SQLITE_FCNTL_PERSIST_WAL 10
1086#define SQLITE_FCNTL_OVERWRITE 11
1087#define SQLITE_FCNTL_VFSNAME 12
1088#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13
1089#define SQLITE_FCNTL_PRAGMA 14
1090#define SQLITE_FCNTL_BUSYHANDLER 15
1091#define SQLITE_FCNTL_TEMPFILENAME 16
1092#define SQLITE_FCNTL_MMAP_SIZE 18
1093#define SQLITE_FCNTL_TRACE 19
1094#define SQLITE_FCNTL_HAS_MOVED 20
1095#define SQLITE_FCNTL_SYNC 21
1096#define SQLITE_FCNTL_COMMIT_PHASETWO 22
1097#define SQLITE_FCNTL_WIN32_SET_HANDLE 23
1098#define SQLITE_FCNTL_WAL_BLOCK 24
1099#define SQLITE_FCNTL_ZIPVFS 25
1100#define SQLITE_FCNTL_RBU 26
1101#define SQLITE_FCNTL_VFS_POINTER 27
1102#define SQLITE_FCNTL_JOURNAL_POINTER 28
1103#define SQLITE_FCNTL_WIN32_GET_HANDLE 29
1104#define SQLITE_FCNTL_PDB 30
1105#define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31
1106#define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32
1107#define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33
1108#define SQLITE_FCNTL_LOCK_TIMEOUT 34
1109
1110/* deprecated names */
1111#define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE
1112#define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE
1113#define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO
1114
1115
1116/*
1117** CAPI3REF: Mutex Handle
1118**
1119** The mutex module within SQLite defines [sqlite3_mutex] to be an
1120** abstract type for a mutex object. The SQLite core never looks
1121** at the internal representation of an [sqlite3_mutex]. It only
1122** deals with pointers to the [sqlite3_mutex] object.
1123**
1124** Mutexes are created using [sqlite3_mutex_alloc()].
1125*/
1126typedef struct sqlite3_mutex sqlite3_mutex;
1127
1128/*
1129** CAPI3REF: Loadable Extension Thunk
1130**
1131** A pointer to the opaque sqlite3_api_routines structure is passed as
1132** the third parameter to entry points of [loadable extensions]. This
1133** structure must be typedefed in order to work around compiler warnings
1134** on some platforms.
1135*/
1136typedef struct sqlite3_api_routines sqlite3_api_routines;
1137
1138/*
1139** CAPI3REF: OS Interface Object
1140**
1141** An instance of the sqlite3_vfs object defines the interface between
1142** the SQLite core and the underlying operating system. The "vfs"
1143** in the name of the object stands for "virtual file system". See
1144** the [VFS | VFS documentation] for further information.
1145**
1146** The VFS interface is sometimes extended by adding new methods onto
1147** the end. Each time such an extension occurs, the iVersion field
1148** is incremented. The iVersion value started out as 1 in
1149** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2
1150** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased
1151** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields
1152** may be appended to the sqlite3_vfs object and the iVersion value
1153** may increase again in future versions of SQLite.
1154** Note that the structure
1155** of the sqlite3_vfs object changes in the transition from
1156** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0]
1157** and yet the iVersion field was not modified.
1158**
1159** The szOsFile field is the size of the subclassed [sqlite3_file]
1160** structure used by this VFS. mxPathname is the maximum length of
1161** a pathname in this VFS.
1162**
1163** Registered sqlite3_vfs objects are kept on a linked list formed by
1164** the pNext pointer. The [sqlite3_vfs_register()]
1165** and [sqlite3_vfs_unregister()] interfaces manage this list
1166** in a thread-safe way. The [sqlite3_vfs_find()] interface
1167** searches the list. Neither the application code nor the VFS
1168** implementation should use the pNext pointer.
1169**
1170** The pNext field is the only field in the sqlite3_vfs
1171** structure that SQLite will ever modify. SQLite will only access
1172** or modify this field while holding a particular static mutex.
1173** The application should never modify anything within the sqlite3_vfs
1174** object once the object has been registered.
1175**
1176** The zName field holds the name of the VFS module. The name must
1177** be unique across all VFS modules.
1178**
1179** [[sqlite3_vfs.xOpen]]
1180** ^SQLite guarantees that the zFilename parameter to xOpen
1181** is either a NULL pointer or string obtained
1182** from xFullPathname() with an optional suffix added.
1183** ^If a suffix is added to the zFilename parameter, it will
1184** consist of a single "-" character followed by no more than
1185** 11 alphanumeric and/or "-" characters.
1186** ^SQLite further guarantees that
1187** the string will be valid and unchanged until xClose() is
1188** called. Because of the previous sentence,
1189** the [sqlite3_file] can safely store a pointer to the
1190** filename if it needs to remember the filename for some reason.
1191** If the zFilename parameter to xOpen is a NULL pointer then xOpen
1192** must invent its own temporary name for the file. ^Whenever the
1193** xFilename parameter is NULL it will also be the case that the
1194** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
1195**
1196** The flags argument to xOpen() includes all bits set in
1197** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()]
1198** or [sqlite3_open16()] is used, then flags includes at least
1199** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE].
1200** If xOpen() opens a file read-only then it sets *pOutFlags to
1201** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set.
1202**
1203** ^(SQLite will also add one of the following flags to the xOpen()
1204** call, depending on the object being opened:
1205**
1206** <ul>
1207** <li> [SQLITE_OPEN_MAIN_DB]
1208** <li> [SQLITE_OPEN_MAIN_JOURNAL]
1209** <li> [SQLITE_OPEN_TEMP_DB]
1210** <li> [SQLITE_OPEN_TEMP_JOURNAL]
1211** <li> [SQLITE_OPEN_TRANSIENT_DB]
1212** <li> [SQLITE_OPEN_SUBJOURNAL]
1213** <li> [SQLITE_OPEN_MASTER_JOURNAL]
1214** <li> [SQLITE_OPEN_WAL]
1215** </ul>)^
1216**
1217** The file I/O implementation can use the object type flags to
1218** change the way it deals with files. For example, an application
1219** that does not care about crash recovery or rollback might make
1220** the open of a journal file a no-op. Writes to this journal would
1221** also be no-ops, and any attempt to read the journal would return
1222** SQLITE_IOERR. Or the implementation might recognize that a database
1223** file will be doing page-aligned sector reads and writes in a random
1224** order and set up its I/O subsystem accordingly.
1225**
1226** SQLite might also add one of the following flags to the xOpen method:
1227**
1228** <ul>
1229** <li> [SQLITE_OPEN_DELETEONCLOSE]
1230** <li> [SQLITE_OPEN_EXCLUSIVE]
1231** </ul>
1232**
1233** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
1234** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE]
1235** will be set for TEMP databases and their journals, transient
1236** databases, and subjournals.
1237**
1238** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
1239** with the [SQLITE_OPEN_CREATE] flag, which are both directly
1240** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
1241** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the
1242** SQLITE_OPEN_CREATE, is used to indicate that file should always
1243** be created, and that it is an error if it already exists.
1244** It is <i>not</i> used to indicate the file should be opened
1245** for exclusive access.
1246**
1247** ^At least szOsFile bytes of memory are allocated by SQLite
1248** to hold the [sqlite3_file] structure passed as the third
1249** argument to xOpen. The xOpen method does not have to
1250** allocate the structure; it should just fill it in. Note that
1251** the xOpen method must set the sqlite3_file.pMethods to either
1252** a valid [sqlite3_io_methods] object or to NULL. xOpen must do
1253** this even if the open fails. SQLite expects that the sqlite3_file.pMethods
1254** element will be valid after xOpen returns regardless of the success
1255** or failure of the xOpen call.
1256**
1257** [[sqlite3_vfs.xAccess]]
1258** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
1259** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
1260** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
1261** to test whether a file is at least readable. The file can be a
1262** directory.
1263**
1264** ^SQLite will always allocate at least mxPathname+1 bytes for the
1265** output buffer xFullPathname. The exact size of the output buffer
1266** is also passed as a parameter to both methods. If the output buffer
1267** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
1268** handled as a fatal error by SQLite, vfs implementations should endeavor
1269** to prevent this by setting mxPathname to a sufficiently large value.
1270**
1271** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
1272** interfaces are not strictly a part of the filesystem, but they are
1273** included in the VFS structure for completeness.
1274** The xRandomness() function attempts to return nBytes bytes
1275** of good-quality randomness into zOut. The return value is
1276** the actual number of bytes of randomness obtained.
1277** The xSleep() method causes the calling thread to sleep for at
1278** least the number of microseconds given. ^The xCurrentTime()
1279** method returns a Julian Day Number for the current date and time as
1280** a floating point value.
1281** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
1282** Day Number multiplied by 86400000 (the number of milliseconds in
1283** a 24-hour day).
1284** ^SQLite will use the xCurrentTimeInt64() method to get the current
1285** date and time if that method is available (if iVersion is 2 or
1286** greater and the function pointer is not NULL) and will fall back
1287** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
1288**
1289** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces
1290** are not used by the SQLite core. These optional interfaces are provided
1291** by some VFSes to facilitate testing of the VFS code. By overriding
1292** system calls with functions under its control, a test program can
1293** simulate faults and error conditions that would otherwise be difficult
1294** or impossible to induce. The set of system calls that can be overridden
1295** varies from one VFS to another, and from one version of the same VFS to the
1296** next. Applications that use these interfaces must be prepared for any
1297** or all of these interfaces to be NULL or for their behavior to change
1298** from one release to the next. Applications must not attempt to access
1299** any of these methods if the iVersion of the VFS is less than 3.
1300*/
1301typedef struct sqlite3_vfs sqlite3_vfs;
1302typedef void (*sqlite3_syscall_ptr)(void);
1303struct sqlite3_vfs {
1304 int iVersion; /* Structure version number (currently 3) */
1305 int szOsFile; /* Size of subclassed sqlite3_file */
1306 int mxPathname; /* Maximum file pathname length */
1307 sqlite3_vfs *pNext; /* Next registered VFS */
1308 const char *zName; /* Name of this virtual file system */
1309 void *pAppData; /* Pointer to application-specific data */
1310 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*,
1311 int flags, int *pOutFlags);
1312 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
1313 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);
1314 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
1315 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
1316 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
1317 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);
1318 void (*xDlClose)(sqlite3_vfs*, void*);
1319 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
1320 int (*xSleep)(sqlite3_vfs*, int microseconds);
1321 int (*xCurrentTime)(sqlite3_vfs*, double*);
1322 int (*xGetLastError)(sqlite3_vfs*, int, char *);
1323 /*
1324 ** The methods above are in version 1 of the sqlite_vfs object
1325 ** definition. Those that follow are added in version 2 or later
1326 */
1327 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
1328 /*
1329 ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
1330 ** Those below are for version 3 and greater.
1331 */
1332 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr);
1333 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName);
1334 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);
1335 /*
1336 ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
1337 ** New fields may be appended in future versions. The iVersion
1338 ** value will increment whenever this happens.
1339 */
1340};
1341
1342/*
1343** CAPI3REF: Flags for the xAccess VFS method
1344**
1345** These integer constants can be used as the third parameter to
1346** the xAccess method of an [sqlite3_vfs] object. They determine
1347** what kind of permissions the xAccess method is looking for.
1348** With SQLITE_ACCESS_EXISTS, the xAccess method
1349** simply checks whether the file exists.
1350** With SQLITE_ACCESS_READWRITE, the xAccess method
1351** checks whether the named directory is both readable and writable
1352** (in other words, if files can be added, removed, and renamed within
1353** the directory).
1354** The SQLITE_ACCESS_READWRITE constant is currently used only by the
1355** [temp_store_directory pragma], though this could change in a future
1356** release of SQLite.
1357** With SQLITE_ACCESS_READ, the xAccess method
1358** checks whether the file is readable. The SQLITE_ACCESS_READ constant is
1359** currently unused, though it might be used in a future release of
1360** SQLite.
1361*/
1362#define SQLITE_ACCESS_EXISTS 0
1363#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */
1364#define SQLITE_ACCESS_READ 2 /* Unused */
1365
1366/*
1367** CAPI3REF: Flags for the xShmLock VFS method
1368**
1369** These integer constants define the various locking operations
1370** allowed by the xShmLock method of [sqlite3_io_methods]. The
1371** following are the only legal combinations of flags to the
1372** xShmLock method:
1373**
1374** <ul>
1375** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED
1376** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE
1377** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED
1378** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE
1379** </ul>
1380**
1381** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
1382** was given on the corresponding lock.
1383**
1384** The xShmLock method can transition between unlocked and SHARED or
1385** between unlocked and EXCLUSIVE. It cannot transition between SHARED
1386** and EXCLUSIVE.
1387*/
1388#define SQLITE_SHM_UNLOCK 1
1389#define SQLITE_SHM_LOCK 2
1390#define SQLITE_SHM_SHARED 4
1391#define SQLITE_SHM_EXCLUSIVE 8
1392
1393/*
1394** CAPI3REF: Maximum xShmLock index
1395**
1396** The xShmLock method on [sqlite3_io_methods] may use values
1397** between 0 and this upper bound as its "offset" argument.
1398** The SQLite core will never attempt to acquire or release a
1399** lock outside of this range
1400*/
1401#define SQLITE_SHM_NLOCK 8
1402
1403
1404/*
1405** CAPI3REF: Initialize The SQLite Library
1406**
1407** ^The sqlite3_initialize() routine initializes the
1408** SQLite library. ^The sqlite3_shutdown() routine
1409** deallocates any resources that were allocated by sqlite3_initialize().
1410** These routines are designed to aid in process initialization and
1411** shutdown on embedded systems. Workstation applications using
1412** SQLite normally do not need to invoke either of these routines.
1413**
1414** A call to sqlite3_initialize() is an "effective" call if it is
1415** the first time sqlite3_initialize() is invoked during the lifetime of
1416** the process, or if it is the first time sqlite3_initialize() is invoked
1417** following a call to sqlite3_shutdown(). ^(Only an effective call
1418** of sqlite3_initialize() does any initialization. All other calls
1419** are harmless no-ops.)^
1420**
1421** A call to sqlite3_shutdown() is an "effective" call if it is the first
1422** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only
1423** an effective call to sqlite3_shutdown() does any deinitialization.
1424** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
1425**
1426** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
1427** is not. The sqlite3_shutdown() interface must only be called from a
1428** single thread. All open [database connections] must be closed and all
1429** other SQLite resources must be deallocated prior to invoking
1430** sqlite3_shutdown().
1431**
1432** Among other things, ^sqlite3_initialize() will invoke
1433** sqlite3_os_init(). Similarly, ^sqlite3_shutdown()
1434** will invoke sqlite3_os_end().
1435**
1436** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
1437** ^If for some reason, sqlite3_initialize() is unable to initialize
1438** the library (perhaps it is unable to allocate a needed resource such
1439** as a mutex) it returns an [error code] other than [SQLITE_OK].
1440**
1441** ^The sqlite3_initialize() routine is called internally by many other
1442** SQLite interfaces so that an application usually does not need to
1443** invoke sqlite3_initialize() directly. For example, [sqlite3_open()]
1444** calls sqlite3_initialize() so the SQLite library will be automatically
1445** initialized when [sqlite3_open()] is called if it has not be initialized
1446** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
1447** compile-time option, then the automatic calls to sqlite3_initialize()
1448** are omitted and the application must call sqlite3_initialize() directly
1449** prior to using any other SQLite interface. For maximum portability,
1450** it is recommended that applications always invoke sqlite3_initialize()
1451** directly prior to using any other SQLite interface. Future releases
1452** of SQLite may require this. In other words, the behavior exhibited
1453** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
1454** default behavior in some future release of SQLite.
1455**
1456** The sqlite3_os_init() routine does operating-system specific
1457** initialization of the SQLite library. The sqlite3_os_end()
1458** routine undoes the effect of sqlite3_os_init(). Typical tasks
1459** performed by these routines include allocation or deallocation
1460** of static resources, initialization of global variables,
1461** setting up a default [sqlite3_vfs] module, or setting up
1462** a default configuration using [sqlite3_config()].
1463**
1464** The application should never invoke either sqlite3_os_init()
1465** or sqlite3_os_end() directly. The application should only invoke
1466** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init()
1467** interface is called automatically by sqlite3_initialize() and
1468** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate
1469** implementations for sqlite3_os_init() and sqlite3_os_end()
1470** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
1471** When [custom builds | built for other platforms]
1472** (using the [SQLITE_OS_OTHER=1] compile-time
1473** option) the application must supply a suitable implementation for
1474** sqlite3_os_init() and sqlite3_os_end(). An application-supplied
1475** implementation of sqlite3_os_init() or sqlite3_os_end()
1476** must return [SQLITE_OK] on success and some other [error code] upon
1477** failure.
1478*/
1479SQLITE_API int sqlite3_initialize(void);
1480SQLITE_API int sqlite3_shutdown(void);
1481SQLITE_API int sqlite3_os_init(void);
1482SQLITE_API int sqlite3_os_end(void);
1483
1484/*
1485** CAPI3REF: Configuring The SQLite Library
1486**
1487** The sqlite3_config() interface is used to make global configuration
1488** changes to SQLite in order to tune SQLite to the specific needs of
1489** the application. The default configuration is recommended for most
1490** applications and so this routine is usually not necessary. It is
1491** provided to support rare applications with unusual needs.
1492**
1493** <b>The sqlite3_config() interface is not threadsafe. The application
1494** must ensure that no other SQLite interfaces are invoked by other
1495** threads while sqlite3_config() is running.</b>
1496**
1497** The sqlite3_config() interface
1498** may only be invoked prior to library initialization using
1499** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
1500** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
1501** [sqlite3_shutdown()] then it will return SQLITE_MISUSE.
1502** Note, however, that ^sqlite3_config() can be called as part of the
1503** implementation of an application-defined [sqlite3_os_init()].
1504**
1505** The first argument to sqlite3_config() is an integer
1506** [configuration option] that determines
1507** what property of SQLite is to be configured. Subsequent arguments
1508** vary depending on the [configuration option]
1509** in the first argument.
1510**
1511** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
1512** ^If the option is unknown or SQLite is unable to set the option
1513** then this routine returns a non-zero [error code].
1514*/
1515SQLITE_API int sqlite3_config(int, ...);
1516
1517/*
1518** CAPI3REF: Configure database connections
1519** METHOD: sqlite3
1520**
1521** The sqlite3_db_config() interface is used to make configuration
1522** changes to a [database connection]. The interface is similar to
1523** [sqlite3_config()] except that the changes apply to a single
1524** [database connection] (specified in the first argument).
1525**
1526** The second argument to sqlite3_db_config(D,V,...) is the
1527** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code
1528** that indicates what aspect of the [database connection] is being configured.
1529** Subsequent arguments vary depending on the configuration verb.
1530**
1531** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
1532** the call is considered successful.
1533*/
1534SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...);
1535
1536/*
1537** CAPI3REF: Memory Allocation Routines
1538**
1539** An instance of this object defines the interface between SQLite
1540** and low-level memory allocation routines.
1541**
1542** This object is used in only one place in the SQLite interface.
1543** A pointer to an instance of this object is the argument to
1544** [sqlite3_config()] when the configuration option is
1545** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].
1546** By creating an instance of this object
1547** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
1548** during configuration, an application can specify an alternative
1549** memory allocation subsystem for SQLite to use for all of its
1550** dynamic memory needs.
1551**
1552** Note that SQLite comes with several [built-in memory allocators]
1553** that are perfectly adequate for the overwhelming majority of applications
1554** and that this object is only useful to a tiny minority of applications
1555** with specialized memory allocation requirements. This object is
1556** also used during testing of SQLite in order to specify an alternative
1557** memory allocator that simulates memory out-of-memory conditions in
1558** order to verify that SQLite recovers gracefully from such
1559** conditions.
1560**
1561** The xMalloc, xRealloc, and xFree methods must work like the
1562** malloc(), realloc() and free() functions from the standard C library.
1563** ^SQLite guarantees that the second argument to
1564** xRealloc is always a value returned by a prior call to xRoundup.
1565**
1566** xSize should return the allocated size of a memory allocation
1567** previously obtained from xMalloc or xRealloc. The allocated size
1568** is always at least as big as the requested size but may be larger.
1569**
1570** The xRoundup method returns what would be the allocated size of
1571** a memory allocation given a particular requested size. Most memory
1572** allocators round up memory allocations at least to the next multiple
1573** of 8. Some allocators round up to a larger multiple or to a power of 2.
1574** Every memory allocation request coming in through [sqlite3_malloc()]
1575** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0,
1576** that causes the corresponding memory allocation to fail.
1577**
1578** The xInit method initializes the memory allocator. For example,
1579** it might allocate any require mutexes or initialize internal data
1580** structures. The xShutdown method is invoked (indirectly) by
1581** [sqlite3_shutdown()] and should deallocate any resources acquired
1582** by xInit. The pAppData pointer is used as the only parameter to
1583** xInit and xShutdown.
1584**
1585** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes
1586** the xInit method, so the xInit method need not be threadsafe. The
1587** xShutdown method is only called from [sqlite3_shutdown()] so it does
1588** not need to be threadsafe either. For all other methods, SQLite
1589** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
1590** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
1591** it is by default) and so the methods are automatically serialized.
1592** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
1593** methods must be threadsafe or else make their own arrangements for
1594** serialization.
1595**
1596** SQLite will never invoke xInit() more than once without an intervening
1597** call to xShutdown().
1598*/
1599typedef struct sqlite3_mem_methods sqlite3_mem_methods;
1600struct sqlite3_mem_methods {
1601 void *(*xMalloc)(int); /* Memory allocation function */
1602 void (*xFree)(void*); /* Free a prior allocation */
1603 void *(*xRealloc)(void*,int); /* Resize an allocation */
1604 int (*xSize)(void*); /* Return the size of an allocation */
1605 int (*xRoundup)(int); /* Round up request size to allocation size */
1606 int (*xInit)(void*); /* Initialize the memory allocator */
1607 void (*xShutdown)(void*); /* Deinitialize the memory allocator */
1608 void *pAppData; /* Argument to xInit() and xShutdown() */
1609};
1610
1611/*
1612** CAPI3REF: Configuration Options
1613** KEYWORDS: {configuration option}
1614**
1615** These constants are the available integer configuration options that
1616** can be passed as the first argument to the [sqlite3_config()] interface.
1617**
1618** New configuration options may be added in future releases of SQLite.
1619** Existing configuration options might be discontinued. Applications
1620** should check the return code from [sqlite3_config()] to make sure that
1621** the call worked. The [sqlite3_config()] interface will return a
1622** non-zero [error code] if a discontinued or unsupported configuration option
1623** is invoked.
1624**
1625** <dl>
1626** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
1627** <dd>There are no arguments to this option. ^This option sets the
1628** [threading mode] to Single-thread. In other words, it disables
1629** all mutexing and puts SQLite into a mode where it can only be used
1630** by a single thread. ^If SQLite is compiled with
1631** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1632** it is not possible to change the [threading mode] from its default
1633** value of Single-thread and so [sqlite3_config()] will return
1634** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
1635** configuration option.</dd>
1636**
1637** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt>
1638** <dd>There are no arguments to this option. ^This option sets the
1639** [threading mode] to Multi-thread. In other words, it disables
1640** mutexing on [database connection] and [prepared statement] objects.
1641** The application is responsible for serializing access to
1642** [database connections] and [prepared statements]. But other mutexes
1643** are enabled so that SQLite will be safe to use in a multi-threaded
1644** environment as long as no two threads attempt to use the same
1645** [database connection] at the same time. ^If SQLite is compiled with
1646** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1647** it is not possible to set the Multi-thread [threading mode] and
1648** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1649** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
1650**
1651** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt>
1652** <dd>There are no arguments to this option. ^This option sets the
1653** [threading mode] to Serialized. In other words, this option enables
1654** all mutexes including the recursive
1655** mutexes on [database connection] and [prepared statement] objects.
1656** In this mode (which is the default when SQLite is compiled with
1657** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
1658** to [database connections] and [prepared statements] so that the
1659** application is free to use the same [database connection] or the
1660** same [prepared statement] in different threads at the same time.
1661** ^If SQLite is compiled with
1662** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1663** it is not possible to set the Serialized [threading mode] and
1664** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1665** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
1666**
1667** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
1668** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is
1669** a pointer to an instance of the [sqlite3_mem_methods] structure.
1670** The argument specifies
1671** alternative low-level memory allocation routines to be used in place of
1672** the memory allocation routines built into SQLite.)^ ^SQLite makes
1673** its own private copy of the content of the [sqlite3_mem_methods] structure
1674** before the [sqlite3_config()] call returns.</dd>
1675**
1676** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
1677** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which
1678** is a pointer to an instance of the [sqlite3_mem_methods] structure.
1679** The [sqlite3_mem_methods]
1680** structure is filled with the currently defined memory allocation routines.)^
1681** This option can be used to overload the default memory allocation
1682** routines with a wrapper that simulations memory allocation failure or
1683** tracks memory usage, for example. </dd>
1684**
1685** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt>
1686** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of
1687** type int, interpreted as a boolean, which if true provides a hint to
1688** SQLite that it should avoid large memory allocations if possible.
1689** SQLite will run faster if it is free to make large memory allocations,
1690** but some application might prefer to run slower in exchange for
1691** guarantees about memory fragmentation that are possible if large
1692** allocations are avoided. This hint is normally off.
1693** </dd>
1694**
1695** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
1696** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int,
1697** interpreted as a boolean, which enables or disables the collection of
1698** memory allocation statistics. ^(When memory allocation statistics are
1699** disabled, the following SQLite interfaces become non-operational:
1700** <ul>
1701** <li> [sqlite3_memory_used()]
1702** <li> [sqlite3_memory_highwater()]
1703** <li> [sqlite3_soft_heap_limit64()]
1704** <li> [sqlite3_status64()]
1705** </ul>)^
1706** ^Memory allocation statistics are enabled by default unless SQLite is
1707** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
1708** allocation statistics are disabled by default.
1709** </dd>
1710**
1711** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
1712** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used.
1713** </dd>
1714**
1715** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
1716** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool
1717** that SQLite can use for the database page cache with the default page
1718** cache implementation.
1719** This configuration option is a no-op if an application-define page
1720** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2].
1721** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to
1722** 8-byte aligned memory (pMem), the size of each page cache line (sz),
1723** and the number of cache lines (N).
1724** The sz argument should be the size of the largest database page
1725** (a power of two between 512 and 65536) plus some extra bytes for each
1726** page header. ^The number of extra bytes needed by the page header
1727** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ].
1728** ^It is harmless, apart from the wasted memory,
1729** for the sz parameter to be larger than necessary. The pMem
1730** argument must be either a NULL pointer or a pointer to an 8-byte
1731** aligned block of memory of at least sz*N bytes, otherwise
1732** subsequent behavior is undefined.
1733** ^When pMem is not NULL, SQLite will strive to use the memory provided
1734** to satisfy page cache needs, falling back to [sqlite3_malloc()] if
1735** a page cache line is larger than sz bytes or if all of the pMem buffer
1736** is exhausted.
1737** ^If pMem is NULL and N is non-zero, then each database connection
1738** does an initial bulk allocation for page cache memory
1739** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or
1740** of -1024*N bytes if N is negative, . ^If additional
1741** page cache memory is needed beyond what is provided by the initial
1742** allocation, then SQLite goes to [sqlite3_malloc()] separately for each
1743** additional cache line. </dd>
1744**
1745** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
1746** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer
1747** that SQLite will use for all of its dynamic memory allocation needs
1748** beyond those provided for by [SQLITE_CONFIG_PAGECACHE].
1749** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled
1750** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns
1751** [SQLITE_ERROR] if invoked otherwise.
1752** ^There are three arguments to SQLITE_CONFIG_HEAP:
1753** An 8-byte aligned pointer to the memory,
1754** the number of bytes in the memory buffer, and the minimum allocation size.
1755** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
1756** to using its default memory allocator (the system malloc() implementation),
1757** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the
1758** memory pointer is not NULL then the alternative memory
1759** allocator is engaged to handle all of SQLites memory allocation needs.
1760** The first pointer (the memory pointer) must be aligned to an 8-byte
1761** boundary or subsequent behavior of SQLite will be undefined.
1762** The minimum allocation size is capped at 2**12. Reasonable values
1763** for the minimum allocation size are 2**5 through 2**8.</dd>
1764**
1765** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
1766** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a
1767** pointer to an instance of the [sqlite3_mutex_methods] structure.
1768** The argument specifies alternative low-level mutex routines to be used
1769** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of
1770** the content of the [sqlite3_mutex_methods] structure before the call to
1771** [sqlite3_config()] returns. ^If SQLite is compiled with
1772** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1773** the entire mutexing subsystem is omitted from the build and hence calls to
1774** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
1775** return [SQLITE_ERROR].</dd>
1776**
1777** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
1778** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which
1779** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The
1780** [sqlite3_mutex_methods]
1781** structure is filled with the currently defined mutex routines.)^
1782** This option can be used to overload the default mutex allocation
1783** routines with a wrapper used to track mutex usage for performance
1784** profiling or testing, for example. ^If SQLite is compiled with
1785** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1786** the entire mutexing subsystem is omitted from the build and hence calls to
1787** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
1788** return [SQLITE_ERROR].</dd>
1789**
1790** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
1791** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine
1792** the default size of lookaside memory on each [database connection].
1793** The first argument is the
1794** size of each lookaside buffer slot and the second is the number of
1795** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE
1796** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE]
1797** option to [sqlite3_db_config()] can be used to change the lookaside
1798** configuration on individual connections.)^ </dd>
1799**
1800** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt>
1801** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is
1802** a pointer to an [sqlite3_pcache_methods2] object. This object specifies
1803** the interface to a custom page cache implementation.)^
1804** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd>
1805**
1806** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>
1807** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which
1808** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of
1809** the current page cache implementation into that object.)^ </dd>
1810**
1811** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
1812** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite
1813** global [error log].
1814** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
1815** function with a call signature of void(*)(void*,int,const char*),
1816** and a pointer to void. ^If the function pointer is not NULL, it is
1817** invoked by [sqlite3_log()] to process each logging event. ^If the
1818** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
1819** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
1820** passed through as the first parameter to the application-defined logger
1821** function whenever that function is invoked. ^The second parameter to
1822** the logger function is a copy of the first parameter to the corresponding
1823** [sqlite3_log()] call and is intended to be a [result code] or an
1824** [extended result code]. ^The third parameter passed to the logger is
1825** log message after formatting via [sqlite3_snprintf()].
1826** The SQLite logging interface is not reentrant; the logger function
1827** supplied by the application must not invoke any SQLite interface.
1828** In a multi-threaded application, the application-defined logger
1829** function must be threadsafe. </dd>
1830**
1831** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
1832** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int.
1833** If non-zero, then URI handling is globally enabled. If the parameter is zero,
1834** then URI handling is globally disabled.)^ ^If URI handling is globally
1835** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()],
1836** [sqlite3_open16()] or
1837** specified as part of [ATTACH] commands are interpreted as URIs, regardless
1838** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
1839** connection is opened. ^If it is globally disabled, filenames are
1840** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
1841** database connection is opened. ^(By default, URI handling is globally
1842** disabled. The default value may be changed by compiling with the
1843** [SQLITE_USE_URI] symbol defined.)^
1844**
1845** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN
1846** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer
1847** argument which is interpreted as a boolean in order to enable or disable
1848** the use of covering indices for full table scans in the query optimizer.
1849** ^The default setting is determined
1850** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on"
1851** if that compile-time option is omitted.
1852** The ability to disable the use of covering indices for full table scans
1853** is because some incorrectly coded legacy applications might malfunction
1854** when the optimization is enabled. Providing the ability to
1855** disable the optimization allows the older, buggy application code to work
1856** without change even with newer versions of SQLite.
1857**
1858** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]]
1859** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE
1860** <dd> These options are obsolete and should not be used by new code.
1861** They are retained for backwards compatibility but are now no-ops.
1862** </dd>
1863**
1864** [[SQLITE_CONFIG_SQLLOG]]
1865** <dt>SQLITE_CONFIG_SQLLOG
1866** <dd>This option is only available if sqlite is compiled with the
1867** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should
1868** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int).
1869** The second should be of type (void*). The callback is invoked by the library
1870** in three separate circumstances, identified by the value passed as the
1871** fourth parameter. If the fourth parameter is 0, then the database connection
1872** passed as the second argument has just been opened. The third argument
1873** points to a buffer containing the name of the main database file. If the
1874** fourth parameter is 1, then the SQL statement that the third parameter
1875** points to has just been executed. Or, if the fourth parameter is 2, then
1876** the connection being passed as the second parameter is being closed. The
1877** third parameter is passed NULL In this case. An example of using this
1878** configuration option can be seen in the "test_sqllog.c" source file in
1879** the canonical SQLite source tree.</dd>
1880**
1881** [[SQLITE_CONFIG_MMAP_SIZE]]
1882** <dt>SQLITE_CONFIG_MMAP_SIZE
1883** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values
1884** that are the default mmap size limit (the default setting for
1885** [PRAGMA mmap_size]) and the maximum allowed mmap size limit.
1886** ^The default setting can be overridden by each database connection using
1887** either the [PRAGMA mmap_size] command, or by using the
1888** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size
1889** will be silently truncated if necessary so that it does not exceed the
1890** compile-time maximum mmap size set by the
1891** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^
1892** ^If either argument to this option is negative, then that argument is
1893** changed to its compile-time default.
1894**
1895** [[SQLITE_CONFIG_WIN32_HEAPSIZE]]
1896** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE
1897** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is
1898** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro
1899** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value
1900** that specifies the maximum size of the created heap.
1901**
1902** [[SQLITE_CONFIG_PCACHE_HDRSZ]]
1903** <dt>SQLITE_CONFIG_PCACHE_HDRSZ
1904** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which
1905** is a pointer to an integer and writes into that integer the number of extra
1906** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE].
1907** The amount of extra space required can change depending on the compiler,
1908** target platform, and SQLite version.
1909**
1910** [[SQLITE_CONFIG_PMASZ]]
1911** <dt>SQLITE_CONFIG_PMASZ
1912** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which
1913** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded
1914** sorter to that integer. The default minimum PMA Size is set by the
1915** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched
1916** to help with sort operations when multithreaded sorting
1917** is enabled (using the [PRAGMA threads] command) and the amount of content
1918** to be sorted exceeds the page size times the minimum of the
1919** [PRAGMA cache_size] setting and this value.
1920**
1921** [[SQLITE_CONFIG_STMTJRNL_SPILL]]
1922** <dt>SQLITE_CONFIG_STMTJRNL_SPILL
1923** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which
1924** becomes the [statement journal] spill-to-disk threshold.
1925** [Statement journals] are held in memory until their size (in bytes)
1926** exceeds this threshold, at which point they are written to disk.
1927** Or if the threshold is -1, statement journals are always held
1928** exclusively in memory.
1929** Since many statement journals never become large, setting the spill
1930** threshold to a value such as 64KiB can greatly reduce the amount of
1931** I/O required to support statement rollback.
1932** The default value for this setting is controlled by the
1933** [SQLITE_STMTJRNL_SPILL] compile-time option.
1934** </dl>
1935*/
1936#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */
1937#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */
1938#define SQLITE_CONFIG_SERIALIZED 3 /* nil */
1939#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */
1940#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */
1941#define SQLITE_CONFIG_SCRATCH 6 /* No longer used */
1942#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */
1943#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */
1944#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */
1945#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */
1946#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */
1947/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */
1948#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */
1949#define SQLITE_CONFIG_PCACHE 14 /* no-op */
1950#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */
1951#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */
1952#define SQLITE_CONFIG_URI 17 /* int */
1953#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */
1954#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */
1955#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */
1956#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */
1957#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */
1958#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */
1959#define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */
1960#define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */
1961#define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */
1962#define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */
1963
1964/*
1965** CAPI3REF: Database Connection Configuration Options
1966**
1967** These constants are the available integer configuration options that
1968** can be passed as the second argument to the [sqlite3_db_config()] interface.
1969**
1970** New configuration options may be added in future releases of SQLite.
1971** Existing configuration options might be discontinued. Applications
1972** should check the return code from [sqlite3_db_config()] to make sure that
1973** the call worked. ^The [sqlite3_db_config()] interface will return a
1974** non-zero [error code] if a discontinued or unsupported configuration option
1975** is invoked.
1976**
1977** <dl>
1978** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
1979** <dd> ^This option takes three additional arguments that determine the
1980** [lookaside memory allocator] configuration for the [database connection].
1981** ^The first argument (the third parameter to [sqlite3_db_config()] is a
1982** pointer to a memory buffer to use for lookaside memory.
1983** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb
1984** may be NULL in which case SQLite will allocate the
1985** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the
1986** size of each lookaside buffer slot. ^The third argument is the number of
1987** slots. The size of the buffer in the first argument must be greater than
1988** or equal to the product of the second and third arguments. The buffer
1989** must be aligned to an 8-byte boundary. ^If the second argument to
1990** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally
1991** rounded down to the next smaller multiple of 8. ^(The lookaside memory
1992** configuration for a database connection can only be changed when that
1993** connection is not currently using lookaside memory, or in other words
1994** when the "current value" returned by
1995** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero.
1996** Any attempt to change the lookaside memory configuration when lookaside
1997** memory is in use leaves the configuration unchanged and returns
1998** [SQLITE_BUSY].)^</dd>
1999**
2000** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt>
2001** <dd> ^This option is used to enable or disable the enforcement of
2002** [foreign key constraints]. There should be two additional arguments.
2003** The first argument is an integer which is 0 to disable FK enforcement,
2004** positive to enable FK enforcement or negative to leave FK enforcement
2005** unchanged. The second parameter is a pointer to an integer into which
2006** is written 0 or 1 to indicate whether FK enforcement is off or on
2007** following this call. The second parameter may be a NULL pointer, in
2008** which case the FK enforcement setting is not reported back. </dd>
2009**
2010** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>
2011** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
2012** There should be two additional arguments.
2013** The first argument is an integer which is 0 to disable triggers,
2014** positive to enable triggers or negative to leave the setting unchanged.
2015** The second parameter is a pointer to an integer into which
2016** is written 0 or 1 to indicate whether triggers are disabled or enabled
2017** following this call. The second parameter may be a NULL pointer, in
2018** which case the trigger setting is not reported back. </dd>
2019**
2020** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt>
2021** <dd> ^This option is used to enable or disable the two-argument
2022** version of the [fts3_tokenizer()] function which is part of the
2023** [FTS3] full-text search engine extension.
2024** There should be two additional arguments.
2025** The first argument is an integer which is 0 to disable fts3_tokenizer() or
2026** positive to enable fts3_tokenizer() or negative to leave the setting
2027** unchanged.
2028** The second parameter is a pointer to an integer into which
2029** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled
2030** following this call. The second parameter may be a NULL pointer, in
2031** which case the new setting is not reported back. </dd>
2032**
2033** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt>
2034** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()]
2035** interface independently of the [load_extension()] SQL function.
2036** The [sqlite3_enable_load_extension()] API enables or disables both the
2037** C-API [sqlite3_load_extension()] and the SQL function [load_extension()].
2038** There should be two additional arguments.
2039** When the first argument to this interface is 1, then only the C-API is
2040** enabled and the SQL function remains disabled. If the first argument to
2041** this interface is 0, then both the C-API and the SQL function are disabled.
2042** If the first argument is -1, then no changes are made to state of either the
2043** C-API or the SQL function.
2044** The second parameter is a pointer to an integer into which
2045** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface
2046** is disabled or enabled following this call. The second parameter may
2047** be a NULL pointer, in which case the new setting is not reported back.
2048** </dd>
2049**
2050** <dt>SQLITE_DBCONFIG_MAINDBNAME</dt>
2051** <dd> ^This option is used to change the name of the "main" database
2052** schema. ^The sole argument is a pointer to a constant UTF8 string
2053** which will become the new schema name in place of "main". ^SQLite
2054** does not make a copy of the new main schema name string, so the application
2055** must ensure that the argument passed into this DBCONFIG option is unchanged
2056** until after the database connection closes.
2057** </dd>
2058**
2059** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt>
2060** <dd> Usually, when a database in wal mode is closed or detached from a
2061** database handle, SQLite checks if this will mean that there are now no
2062** connections at all to the database. If so, it performs a checkpoint
2063** operation before closing the connection. This option may be used to
2064** override this behaviour. The first parameter passed to this operation
2065** is an integer - positive to disable checkpoints-on-close, or zero (the
2066** default) to enable them, and negative to leave the setting unchanged.
2067** The second parameter is a pointer to an integer
2068** into which is written 0 or 1 to indicate whether checkpoints-on-close
2069** have been disabled - 0 if they are not disabled, 1 if they are.
2070** </dd>
2071**
2072** <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt>
2073** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates
2074** the [query planner stability guarantee] (QPSG). When the QPSG is active,
2075** a single SQL query statement will always use the same algorithm regardless
2076** of values of [bound parameters].)^ The QPSG disables some query optimizations
2077** that look at the values of bound parameters, which can make some queries
2078** slower. But the QPSG has the advantage of more predictable behavior. With
2079** the QPSG active, SQLite will always use the same query plan in the field as
2080** was used during testing in the lab.
2081** The first argument to this setting is an integer which is 0 to disable
2082** the QPSG, positive to enable QPSG, or negative to leave the setting
2083** unchanged. The second parameter is a pointer to an integer into which
2084** is written 0 or 1 to indicate whether the QPSG is disabled or enabled
2085** following this call.
2086** </dd>
2087**
2088** <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt>
2089** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not
2090** include output for any operations performed by trigger programs. This
2091** option is used to set or clear (the default) a flag that governs this
2092** behavior. The first parameter passed to this operation is an integer -
2093** positive to enable output for trigger programs, or zero to disable it,
2094** or negative to leave the setting unchanged.
2095** The second parameter is a pointer to an integer into which is written
2096** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if
2097** it is not disabled, 1 if it is.
2098** </dd>
2099** </dl>
2100*/
2101#define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */
2102#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */
2103#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */
2104#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */
2105#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */
2106#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */
2107#define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */
2108#define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */
2109#define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */
2110#define SQLITE_DBCONFIG_MAX 1008 /* Largest DBCONFIG */
2111
2112/*
2113** CAPI3REF: Enable Or Disable Extended Result Codes
2114** METHOD: sqlite3
2115**
2116** ^The sqlite3_extended_result_codes() routine enables or disables the
2117** [extended result codes] feature of SQLite. ^The extended result
2118** codes are disabled by default for historical compatibility.
2119*/
2120SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);
2121
2122/*
2123** CAPI3REF: Last Insert Rowid
2124** METHOD: sqlite3
2125**
2126** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables)
2127** has a unique 64-bit signed
2128** integer key called the [ROWID | "rowid"]. ^The rowid is always available
2129** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
2130** names are not also used by explicitly declared columns. ^If
2131** the table has a column of type [INTEGER PRIMARY KEY] then that column
2132** is another alias for the rowid.
2133**
2134** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of
2135** the most recent successful [INSERT] into a rowid table or [virtual table]
2136** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not
2137** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred
2138** on the database connection D, then sqlite3_last_insert_rowid(D) returns
2139** zero.
2140**
2141** As well as being set automatically as rows are inserted into database
2142** tables, the value returned by this function may be set explicitly by
2143** [sqlite3_set_last_insert_rowid()]
2144**
2145** Some virtual table implementations may INSERT rows into rowid tables as
2146** part of committing a transaction (e.g. to flush data accumulated in memory
2147** to disk). In this case subsequent calls to this function return the rowid
2148** associated with these internal INSERT operations, which leads to
2149** unintuitive results. Virtual table implementations that do write to rowid
2150** tables in this way can avoid this problem by restoring the original
2151** rowid value using [sqlite3_set_last_insert_rowid()] before returning
2152** control to the user.
2153**
2154** ^(If an [INSERT] occurs within a trigger then this routine will
2155** return the [rowid] of the inserted row as long as the trigger is
2156** running. Once the trigger program ends, the value returned
2157** by this routine reverts to what it was before the trigger was fired.)^
2158**
2159** ^An [INSERT] that fails due to a constraint violation is not a
2160** successful [INSERT] and does not change the value returned by this
2161** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
2162** and INSERT OR ABORT make no changes to the return value of this
2163** routine when their insertion fails. ^(When INSERT OR REPLACE
2164** encounters a constraint violation, it does not fail. The
2165** INSERT continues to completion after deleting rows that caused
2166** the constraint problem so INSERT OR REPLACE will always change
2167** the return value of this interface.)^
2168**
2169** ^For the purposes of this routine, an [INSERT] is considered to
2170** be successful even if it is subsequently rolled back.
2171**
2172** This function is accessible to SQL statements via the
2173** [last_insert_rowid() SQL function].
2174**
2175** If a separate thread performs a new [INSERT] on the same
2176** database connection while the [sqlite3_last_insert_rowid()]
2177** function is running and thus changes the last insert [rowid],
2178** then the value returned by [sqlite3_last_insert_rowid()] is
2179** unpredictable and might not equal either the old or the new
2180** last insert [rowid].
2181*/
2182SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);
2183
2184/*
2185** CAPI3REF: Set the Last Insert Rowid value.
2186** METHOD: sqlite3
2187**
2188** The sqlite3_set_last_insert_rowid(D, R) method allows the application to
2189** set the value returned by calling sqlite3_last_insert_rowid(D) to R
2190** without inserting a row into the database.
2191*/
2192SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64);
2193
2194/*
2195** CAPI3REF: Count The Number Of Rows Modified
2196** METHOD: sqlite3
2197**
2198** ^This function returns the number of rows modified, inserted or
2199** deleted by the most recently completed INSERT, UPDATE or DELETE
2200** statement on the database connection specified by the only parameter.
2201** ^Executing any other type of SQL statement does not modify the value
2202** returned by this function.
2203**
2204** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are
2205** considered - auxiliary changes caused by [CREATE TRIGGER | triggers],
2206** [foreign key actions] or [REPLACE] constraint resolution are not counted.
2207**
2208** Changes to a view that are intercepted by
2209** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value
2210** returned by sqlite3_changes() immediately after an INSERT, UPDATE or
2211** DELETE statement run on a view is always zero. Only changes made to real
2212** tables are counted.
2213**
2214** Things are more complicated if the sqlite3_changes() function is
2215** executed while a trigger program is running. This may happen if the
2216** program uses the [changes() SQL function], or if some other callback
2217** function invokes sqlite3_changes() directly. Essentially:
2218**
2219** <ul>
2220** <li> ^(Before entering a trigger program the value returned by
2221** sqlite3_changes() function is saved. After the trigger program
2222** has finished, the original value is restored.)^
2223**
2224** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE
2225** statement sets the value returned by sqlite3_changes()
2226** upon completion as normal. Of course, this value will not include
2227** any changes performed by sub-triggers, as the sqlite3_changes()
2228** value will be saved and restored after each sub-trigger has run.)^
2229** </ul>
2230**
2231** ^This means that if the changes() SQL function (or similar) is used
2232** by the first INSERT, UPDATE or DELETE statement within a trigger, it
2233** returns the value as set when the calling statement began executing.
2234** ^If it is used by the second or subsequent such statement within a trigger
2235** program, the value returned reflects the number of rows modified by the
2236** previous INSERT, UPDATE or DELETE statement within the same trigger.
2237**
2238** See also the [sqlite3_total_changes()] interface, the
2239** [count_changes pragma], and the [changes() SQL function].
2240**
2241** If a separate thread makes changes on the same database connection
2242** while [sqlite3_changes()] is running then the value returned
2243** is unpredictable and not meaningful.
2244*/
2245SQLITE_API int sqlite3_changes(sqlite3*);
2246
2247/*
2248** CAPI3REF: Total Number Of Rows Modified
2249** METHOD: sqlite3
2250**
2251** ^This function returns the total number of rows inserted, modified or
2252** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed
2253** since the database connection was opened, including those executed as
2254** part of trigger programs. ^Executing any other type of SQL statement
2255** does not affect the value returned by sqlite3_total_changes().
2256**
2257** ^Changes made as part of [foreign key actions] are included in the
2258** count, but those made as part of REPLACE constraint resolution are
2259** not. ^Changes to a view that are intercepted by INSTEAD OF triggers
2260** are not counted.
2261**
2262** See also the [sqlite3_changes()] interface, the
2263** [count_changes pragma], and the [total_changes() SQL function].
2264**
2265** If a separate thread makes changes on the same database connection
2266** while [sqlite3_total_changes()] is running then the value
2267** returned is unpredictable and not meaningful.
2268*/
2269SQLITE_API int sqlite3_total_changes(sqlite3*);
2270
2271/*
2272** CAPI3REF: Interrupt A Long-Running Query
2273** METHOD: sqlite3
2274**
2275** ^This function causes any pending database operation to abort and
2276** return at its earliest opportunity. This routine is typically
2277** called in response to a user action such as pressing "Cancel"
2278** or Ctrl-C where the user wants a long query operation to halt
2279** immediately.
2280**
2281** ^It is safe to call this routine from a thread different from the
2282** thread that is currently running the database operation. But it
2283** is not safe to call this routine with a [database connection] that
2284** is closed or might close before sqlite3_interrupt() returns.
2285**
2286** ^If an SQL operation is very nearly finished at the time when
2287** sqlite3_interrupt() is called, then it might not have an opportunity
2288** to be interrupted and might continue to completion.
2289**
2290** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
2291** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
2292** that is inside an explicit transaction, then the entire transaction
2293** will be rolled back automatically.
2294**
2295** ^The sqlite3_interrupt(D) call is in effect until all currently running
2296** SQL statements on [database connection] D complete. ^Any new SQL statements
2297** that are started after the sqlite3_interrupt() call and before the
2298** running statements reaches zero are interrupted as if they had been
2299** running prior to the sqlite3_interrupt() call. ^New SQL statements
2300** that are started after the running statement count reaches zero are
2301** not effected by the sqlite3_interrupt().
2302** ^A call to sqlite3_interrupt(D) that occurs when there are no running
2303** SQL statements is a no-op and has no effect on SQL statements
2304** that are started after the sqlite3_interrupt() call returns.
2305*/
2306SQLITE_API void sqlite3_interrupt(sqlite3*);
2307
2308/*
2309** CAPI3REF: Determine If An SQL Statement Is Complete
2310**
2311** These routines are useful during command-line input to determine if the
2312** currently entered text seems to form a complete SQL statement or
2313** if additional input is needed before sending the text into
2314** SQLite for parsing. ^These routines return 1 if the input string
2315** appears to be a complete SQL statement. ^A statement is judged to be
2316** complete if it ends with a semicolon token and is not a prefix of a
2317** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within
2318** string literals or quoted identifier names or comments are not
2319** independent tokens (they are part of the token in which they are
2320** embedded) and thus do not count as a statement terminator. ^Whitespace
2321** and comments that follow the final semicolon are ignored.
2322**
2323** ^These routines return 0 if the statement is incomplete. ^If a
2324** memory allocation fails, then SQLITE_NOMEM is returned.
2325**
2326** ^These routines do not parse the SQL statements thus
2327** will not detect syntactically incorrect SQL.
2328**
2329** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior
2330** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
2331** automatically by sqlite3_complete16(). If that initialization fails,
2332** then the return value from sqlite3_complete16() will be non-zero
2333** regardless of whether or not the input SQL is complete.)^
2334**
2335** The input to [sqlite3_complete()] must be a zero-terminated
2336** UTF-8 string.
2337**
2338** The input to [sqlite3_complete16()] must be a zero-terminated
2339** UTF-16 string in native byte order.
2340*/
2341SQLITE_API int sqlite3_complete(const char *sql);
2342SQLITE_API int sqlite3_complete16(const void *sql);
2343
2344/*
2345** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
2346** KEYWORDS: {busy-handler callback} {busy handler}
2347** METHOD: sqlite3
2348**
2349** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X
2350** that might be invoked with argument P whenever
2351** an attempt is made to access a database table associated with
2352** [database connection] D when another thread
2353** or process has the table locked.
2354** The sqlite3_busy_handler() interface is used to implement
2355** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout].
2356**
2357** ^If the busy callback is NULL, then [SQLITE_BUSY]
2358** is returned immediately upon encountering the lock. ^If the busy callback
2359** is not NULL, then the callback might be invoked with two arguments.
2360**
2361** ^The first argument to the busy handler is a copy of the void* pointer which
2362** is the third argument to sqlite3_busy_handler(). ^The second argument to
2363** the busy handler callback is the number of times that the busy handler has
2364** been invoked previously for the same locking event. ^If the
2365** busy callback returns 0, then no additional attempts are made to
2366** access the database and [SQLITE_BUSY] is returned
2367** to the application.
2368** ^If the callback returns non-zero, then another attempt
2369** is made to access the database and the cycle repeats.
2370**
2371** The presence of a busy handler does not guarantee that it will be invoked
2372** when there is lock contention. ^If SQLite determines that invoking the busy
2373** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
2374** to the application instead of invoking the
2375** busy handler.
2376** Consider a scenario where one process is holding a read lock that
2377** it is trying to promote to a reserved lock and
2378** a second process is holding a reserved lock that it is trying
2379** to promote to an exclusive lock. The first process cannot proceed
2380** because it is blocked by the second and the second process cannot
2381** proceed because it is blocked by the first. If both processes
2382** invoke the busy handlers, neither will make any progress. Therefore,
2383** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
2384** will induce the first process to release its read lock and allow
2385** the second process to proceed.
2386**
2387** ^The default busy callback is NULL.
2388**
2389** ^(There can only be a single busy handler defined for each
2390** [database connection]. Setting a new busy handler clears any
2391** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()]
2392** or evaluating [PRAGMA busy_timeout=N] will change the
2393** busy handler and thus clear any previously set busy handler.
2394**
2395** The busy callback should not take any actions which modify the
2396** database connection that invoked the busy handler. In other words,
2397** the busy handler is not reentrant. Any such actions
2398** result in undefined behavior.
2399**
2400** A busy handler must not close the database connection
2401** or [prepared statement] that invoked the busy handler.
2402*/
2403SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*);
2404
2405/*
2406** CAPI3REF: Set A Busy Timeout
2407** METHOD: sqlite3
2408**
2409** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
2410** for a specified amount of time when a table is locked. ^The handler
2411** will sleep multiple times until at least "ms" milliseconds of sleeping
2412** have accumulated. ^After at least "ms" milliseconds of sleeping,
2413** the handler returns 0 which causes [sqlite3_step()] to return
2414** [SQLITE_BUSY].
2415**
2416** ^Calling this routine with an argument less than or equal to zero
2417** turns off all busy handlers.
2418**
2419** ^(There can only be a single busy handler for a particular
2420** [database connection] at any given moment. If another busy handler
2421** was defined (using [sqlite3_busy_handler()]) prior to calling
2422** this routine, that other busy handler is cleared.)^
2423**
2424** See also: [PRAGMA busy_timeout]
2425*/
2426SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms);
2427
2428/*
2429** CAPI3REF: Convenience Routines For Running Queries
2430** METHOD: sqlite3
2431**
2432** This is a legacy interface that is preserved for backwards compatibility.
2433** Use of this interface is not recommended.
2434**
2435** Definition: A <b>result table</b> is memory data structure created by the
2436** [sqlite3_get_table()] interface. A result table records the
2437** complete query results from one or more queries.
2438**
2439** The table conceptually has a number of rows and columns. But
2440** these numbers are not part of the result table itself. These
2441** numbers are obtained separately. Let N be the number of rows
2442** and M be the number of columns.
2443**
2444** A result table is an array of pointers to zero-terminated UTF-8 strings.
2445** There are (N+1)*M elements in the array. The first M pointers point
2446** to zero-terminated strings that contain the names of the columns.
2447** The remaining entries all point to query results. NULL values result
2448** in NULL pointers. All other values are in their UTF-8 zero-terminated
2449** string representation as returned by [sqlite3_column_text()].
2450**
2451** A result table might consist of one or more memory allocations.
2452** It is not safe to pass a result table directly to [sqlite3_free()].
2453** A result table should be deallocated using [sqlite3_free_table()].
2454**
2455** ^(As an example of the result table format, suppose a query result
2456** is as follows:
2457**
2458** <blockquote><pre>
2459** Name | Age
2460** -----------------------
2461** Alice | 43
2462** Bob | 28
2463** Cindy | 21
2464** </pre></blockquote>
2465**
2466** There are two column (M==2) and three rows (N==3). Thus the
2467** result table has 8 entries. Suppose the result table is stored
2468** in an array names azResult. Then azResult holds this content:
2469**
2470** <blockquote><pre>
2471** azResult&#91;0] = "Name";
2472** azResult&#91;1] = "Age";
2473** azResult&#91;2] = "Alice";
2474** azResult&#91;3] = "43";
2475** azResult&#91;4] = "Bob";
2476** azResult&#91;5] = "28";
2477** azResult&#91;6] = "Cindy";
2478** azResult&#91;7] = "21";
2479** </pre></blockquote>)^
2480**
2481** ^The sqlite3_get_table() function evaluates one or more
2482** semicolon-separated SQL statements in the zero-terminated UTF-8
2483** string of its 2nd parameter and returns a result table to the
2484** pointer given in its 3rd parameter.
2485**
2486** After the application has finished with the result from sqlite3_get_table(),
2487** it must pass the result table pointer to sqlite3_free_table() in order to
2488** release the memory that was malloced. Because of the way the
2489** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
2490** function must not try to call [sqlite3_free()] directly. Only
2491** [sqlite3_free_table()] is able to release the memory properly and safely.
2492**
2493** The sqlite3_get_table() interface is implemented as a wrapper around
2494** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access
2495** to any internal data structures of SQLite. It uses only the public
2496** interface defined here. As a consequence, errors that occur in the
2497** wrapper layer outside of the internal [sqlite3_exec()] call are not
2498** reflected in subsequent calls to [sqlite3_errcode()] or
2499** [sqlite3_errmsg()].
2500*/
2501SQLITE_API int sqlite3_get_table(
2502 sqlite3 *db, /* An open database */
2503 const char *zSql, /* SQL to be evaluated */
2504 char ***pazResult, /* Results of the query */
2505 int *pnRow, /* Number of result rows written here */
2506 int *pnColumn, /* Number of result columns written here */
2507 char **pzErrmsg /* Error msg written here */
2508);
2509SQLITE_API void sqlite3_free_table(char **result);
2510
2511/*
2512** CAPI3REF: Formatted String Printing Functions
2513**
2514** These routines are work-alikes of the "printf()" family of functions
2515** from the standard C library.
2516** These routines understand most of the common formatting options from
2517** the standard library printf()
2518** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]).
2519** See the [built-in printf()] documentation for details.
2520**
2521** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
2522** results into memory obtained from [sqlite3_malloc64()].
2523** The strings returned by these two routines should be
2524** released by [sqlite3_free()]. ^Both routines return a
2525** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough
2526** memory to hold the resulting string.
2527**
2528** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
2529** the standard C library. The result is written into the
2530** buffer supplied as the second parameter whose size is given by
2531** the first parameter. Note that the order of the
2532** first two parameters is reversed from snprintf().)^ This is an
2533** historical accident that cannot be fixed without breaking
2534** backwards compatibility. ^(Note also that sqlite3_snprintf()
2535** returns a pointer to its buffer instead of the number of
2536** characters actually written into the buffer.)^ We admit that
2537** the number of characters written would be a more useful return
2538** value but we cannot change the implementation of sqlite3_snprintf()
2539** now without breaking compatibility.
2540**
2541** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
2542** guarantees that the buffer is always zero-terminated. ^The first
2543** parameter "n" is the total size of the buffer, including space for
2544** the zero terminator. So the longest string that can be completely
2545** written will be n-1 characters.
2546**
2547** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
2548**
2549** See also: [built-in printf()], [printf() SQL function]
2550*/
2551SQLITE_API char *sqlite3_mprintf(const char*,...);
2552SQLITE_API char *sqlite3_vmprintf(const char*, va_list);
2553SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...);
2554SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list);
2555
2556/*
2557** CAPI3REF: Memory Allocation Subsystem
2558**
2559** The SQLite core uses these three routines for all of its own
2560** internal memory allocation needs. "Core" in the previous sentence
2561** does not include operating-system specific VFS implementation. The
2562** Windows VFS uses native malloc() and free() for some operations.
2563**
2564** ^The sqlite3_malloc() routine returns a pointer to a block
2565** of memory at least N bytes in length, where N is the parameter.
2566** ^If sqlite3_malloc() is unable to obtain sufficient free
2567** memory, it returns a NULL pointer. ^If the parameter N to
2568** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
2569** a NULL pointer.
2570**
2571** ^The sqlite3_malloc64(N) routine works just like
2572** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead
2573** of a signed 32-bit integer.
2574**
2575** ^Calling sqlite3_free() with a pointer previously returned
2576** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
2577** that it might be reused. ^The sqlite3_free() routine is
2578** a no-op if is called with a NULL pointer. Passing a NULL pointer
2579** to sqlite3_free() is harmless. After being freed, memory
2580** should neither be read nor written. Even reading previously freed
2581** memory might result in a segmentation fault or other severe error.
2582** Memory corruption, a segmentation fault, or other severe error
2583** might result if sqlite3_free() is called with a non-NULL pointer that
2584** was not obtained from sqlite3_malloc() or sqlite3_realloc().
2585**
2586** ^The sqlite3_realloc(X,N) interface attempts to resize a
2587** prior memory allocation X to be at least N bytes.
2588** ^If the X parameter to sqlite3_realloc(X,N)
2589** is a NULL pointer then its behavior is identical to calling
2590** sqlite3_malloc(N).
2591** ^If the N parameter to sqlite3_realloc(X,N) is zero or
2592** negative then the behavior is exactly the same as calling
2593** sqlite3_free(X).
2594** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation
2595** of at least N bytes in size or NULL if insufficient memory is available.
2596** ^If M is the size of the prior allocation, then min(N,M) bytes
2597** of the prior allocation are copied into the beginning of buffer returned
2598** by sqlite3_realloc(X,N) and the prior allocation is freed.
2599** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the
2600** prior allocation is not freed.
2601**
2602** ^The sqlite3_realloc64(X,N) interfaces works the same as
2603** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead
2604** of a 32-bit signed integer.
2605**
2606** ^If X is a memory allocation previously obtained from sqlite3_malloc(),
2607** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then
2608** sqlite3_msize(X) returns the size of that memory allocation in bytes.
2609** ^The value returned by sqlite3_msize(X) might be larger than the number
2610** of bytes requested when X was allocated. ^If X is a NULL pointer then
2611** sqlite3_msize(X) returns zero. If X points to something that is not
2612** the beginning of memory allocation, or if it points to a formerly
2613** valid memory allocation that has now been freed, then the behavior
2614** of sqlite3_msize(X) is undefined and possibly harmful.
2615**
2616** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(),
2617** sqlite3_malloc64(), and sqlite3_realloc64()
2618** is always aligned to at least an 8 byte boundary, or to a
2619** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
2620** option is used.
2621**
2622** In SQLite version 3.5.0 and 3.5.1, it was possible to define
2623** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in
2624** implementation of these routines to be omitted. That capability
2625** is no longer provided. Only built-in memory allocators can be used.
2626**
2627** Prior to SQLite version 3.7.10, the Windows OS interface layer called
2628** the system malloc() and free() directly when converting
2629** filenames between the UTF-8 encoding used by SQLite
2630** and whatever filename encoding is used by the particular Windows
2631** installation. Memory allocation errors were detected, but
2632** they were reported back as [SQLITE_CANTOPEN] or
2633** [SQLITE_IOERR] rather than [SQLITE_NOMEM].
2634**
2635** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
2636** must be either NULL or else pointers obtained from a prior
2637** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
2638** not yet been released.
2639**
2640** The application must not read or write any part of
2641** a block of memory after it has been released using
2642** [sqlite3_free()] or [sqlite3_realloc()].
2643*/
2644SQLITE_API void *sqlite3_malloc(int);
2645SQLITE_API void *sqlite3_malloc64(sqlite3_uint64);
2646SQLITE_API void *sqlite3_realloc(void*, int);
2647SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64);
2648SQLITE_API void sqlite3_free(void*);
2649SQLITE_API sqlite3_uint64 sqlite3_msize(void*);
2650
2651/*
2652** CAPI3REF: Memory Allocator Statistics
2653**
2654** SQLite provides these two interfaces for reporting on the status
2655** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
2656** routines, which form the built-in memory allocation subsystem.
2657**
2658** ^The [sqlite3_memory_used()] routine returns the number of bytes
2659** of memory currently outstanding (malloced but not freed).
2660** ^The [sqlite3_memory_highwater()] routine returns the maximum
2661** value of [sqlite3_memory_used()] since the high-water mark
2662** was last reset. ^The values returned by [sqlite3_memory_used()] and
2663** [sqlite3_memory_highwater()] include any overhead
2664** added by SQLite in its implementation of [sqlite3_malloc()],
2665** but not overhead added by the any underlying system library
2666** routines that [sqlite3_malloc()] may call.
2667**
2668** ^The memory high-water mark is reset to the current value of
2669** [sqlite3_memory_used()] if and only if the parameter to
2670** [sqlite3_memory_highwater()] is true. ^The value returned
2671** by [sqlite3_memory_highwater(1)] is the high-water mark
2672** prior to the reset.
2673*/
2674SQLITE_API sqlite3_int64 sqlite3_memory_used(void);
2675SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
2676
2677/*
2678** CAPI3REF: Pseudo-Random Number Generator
2679**
2680** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
2681** select random [ROWID | ROWIDs] when inserting new records into a table that
2682** already uses the largest possible [ROWID]. The PRNG is also used for
2683** the build-in random() and randomblob() SQL functions. This interface allows
2684** applications to access the same PRNG for other purposes.
2685**
2686** ^A call to this routine stores N bytes of randomness into buffer P.
2687** ^The P parameter can be a NULL pointer.
2688**
2689** ^If this routine has not been previously called or if the previous
2690** call had N less than one or a NULL pointer for P, then the PRNG is
2691** seeded using randomness obtained from the xRandomness method of
2692** the default [sqlite3_vfs] object.
2693** ^If the previous call to this routine had an N of 1 or more and a
2694** non-NULL P then the pseudo-randomness is generated
2695** internally and without recourse to the [sqlite3_vfs] xRandomness
2696** method.
2697*/
2698SQLITE_API void sqlite3_randomness(int N, void *P);
2699
2700/*
2701** CAPI3REF: Compile-Time Authorization Callbacks
2702** METHOD: sqlite3
2703** KEYWORDS: {authorizer callback}
2704**
2705** ^This routine registers an authorizer callback with a particular
2706** [database connection], supplied in the first argument.
2707** ^The authorizer callback is invoked as SQL statements are being compiled
2708** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
2709** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()],
2710** and [sqlite3_prepare16_v3()]. ^At various
2711** points during the compilation process, as logic is being created
2712** to perform various actions, the authorizer callback is invoked to
2713** see if those actions are allowed. ^The authorizer callback should
2714** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
2715** specific action but allow the SQL statement to continue to be
2716** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
2717** rejected with an error. ^If the authorizer callback returns
2718** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
2719** then the [sqlite3_prepare_v2()] or equivalent call that triggered
2720** the authorizer will fail with an error message.
2721**
2722** When the callback returns [SQLITE_OK], that means the operation
2723** requested is ok. ^When the callback returns [SQLITE_DENY], the
2724** [sqlite3_prepare_v2()] or equivalent call that triggered the
2725** authorizer will fail with an error message explaining that
2726** access is denied.
2727**
2728** ^The first parameter to the authorizer callback is a copy of the third
2729** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
2730** to the callback is an integer [SQLITE_COPY | action code] that specifies
2731** the particular action to be authorized. ^The third through sixth parameters
2732** to the callback are either NULL pointers or zero-terminated strings
2733** that contain additional details about the action to be authorized.
2734** Applications must always be prepared to encounter a NULL pointer in any
2735** of the third through the sixth parameters of the authorization callback.
2736**
2737** ^If the action code is [SQLITE_READ]
2738** and the callback returns [SQLITE_IGNORE] then the
2739** [prepared statement] statement is constructed to substitute
2740** a NULL value in place of the table column that would have
2741** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE]
2742** return can be used to deny an untrusted user access to individual
2743** columns of a table.
2744** ^When a table is referenced by a [SELECT] but no column values are
2745** extracted from that table (for example in a query like
2746** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback
2747** is invoked once for that table with a column name that is an empty string.
2748** ^If the action code is [SQLITE_DELETE] and the callback returns
2749** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
2750** [truncate optimization] is disabled and all rows are deleted individually.
2751**
2752** An authorizer is used when [sqlite3_prepare | preparing]
2753** SQL statements from an untrusted source, to ensure that the SQL statements
2754** do not try to access data they are not allowed to see, or that they do not
2755** try to execute malicious statements that damage the database. For
2756** example, an application may allow a user to enter arbitrary
2757** SQL queries for evaluation by a database. But the application does
2758** not want the user to be able to make arbitrary changes to the
2759** database. An authorizer could then be put in place while the
2760** user-entered SQL is being [sqlite3_prepare | prepared] that
2761** disallows everything except [SELECT] statements.
2762**
2763** Applications that need to process SQL from untrusted sources
2764** might also consider lowering resource limits using [sqlite3_limit()]
2765** and limiting database size using the [max_page_count] [PRAGMA]
2766** in addition to using an authorizer.
2767**
2768** ^(Only a single authorizer can be in place on a database connection
2769** at a time. Each call to sqlite3_set_authorizer overrides the
2770** previous call.)^ ^Disable the authorizer by installing a NULL callback.
2771** The authorizer is disabled by default.
2772**
2773** The authorizer callback must not do anything that will modify
2774** the database connection that invoked the authorizer callback.
2775** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
2776** database connections for the meaning of "modify" in this paragraph.
2777**
2778** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
2779** statement might be re-prepared during [sqlite3_step()] due to a
2780** schema change. Hence, the application should ensure that the
2781** correct authorizer callback remains in place during the [sqlite3_step()].
2782**
2783** ^Note that the authorizer callback is invoked only during
2784** [sqlite3_prepare()] or its variants. Authorization is not
2785** performed during statement evaluation in [sqlite3_step()], unless
2786** as stated in the previous paragraph, sqlite3_step() invokes
2787** sqlite3_prepare_v2() to reprepare a statement after a schema change.
2788*/
2789SQLITE_API int sqlite3_set_authorizer(
2790 sqlite3*,
2791 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
2792 void *pUserData
2793);
2794
2795/*
2796** CAPI3REF: Authorizer Return Codes
2797**
2798** The [sqlite3_set_authorizer | authorizer callback function] must
2799** return either [SQLITE_OK] or one of these two constants in order
2800** to signal SQLite whether or not the action is permitted. See the
2801** [sqlite3_set_authorizer | authorizer documentation] for additional
2802** information.
2803**
2804** Note that SQLITE_IGNORE is also used as a [conflict resolution mode]
2805** returned from the [sqlite3_vtab_on_conflict()] interface.
2806*/
2807#define SQLITE_DENY 1 /* Abort the SQL statement with an error */
2808#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */
2809
2810/*
2811** CAPI3REF: Authorizer Action Codes
2812**
2813** The [sqlite3_set_authorizer()] interface registers a callback function
2814** that is invoked to authorize certain SQL statement actions. The
2815** second parameter to the callback is an integer code that specifies
2816** what action is being authorized. These are the integer action codes that
2817** the authorizer callback may be passed.
2818**
2819** These action code values signify what kind of operation is to be
2820** authorized. The 3rd and 4th parameters to the authorization
2821** callback function will be parameters or NULL depending on which of these
2822** codes is used as the second parameter. ^(The 5th parameter to the
2823** authorizer callback is the name of the database ("main", "temp",
2824** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback
2825** is the name of the inner-most trigger or view that is responsible for
2826** the access attempt or NULL if this access attempt is directly from
2827** top-level SQL code.
2828*/
2829/******************************************* 3rd ************ 4th ***********/
2830#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */
2831#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */
2832#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */
2833#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */
2834#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */
2835#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */
2836#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */
2837#define SQLITE_CREATE_VIEW 8 /* View Name NULL */
2838#define SQLITE_DELETE 9 /* Table Name NULL */
2839#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */
2840#define SQLITE_DROP_TABLE 11 /* Table Name NULL */
2841#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */
2842#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */
2843#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */
2844#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */
2845#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */
2846#define SQLITE_DROP_VIEW 17 /* View Name NULL */
2847#define SQLITE_INSERT 18 /* Table Name NULL */
2848#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */
2849#define SQLITE_READ 20 /* Table Name Column Name */
2850#define SQLITE_SELECT 21 /* NULL NULL */
2851#define SQLITE_TRANSACTION 22 /* Operation NULL */
2852#define SQLITE_UPDATE 23 /* Table Name Column Name */
2853#define SQLITE_ATTACH 24 /* Filename NULL */
2854#define SQLITE_DETACH 25 /* Database Name NULL */
2855#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */
2856#define SQLITE_REINDEX 27 /* Index Name NULL */
2857#define SQLITE_ANALYZE 28 /* Table Name NULL */
2858#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */
2859#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */
2860#define SQLITE_FUNCTION 31 /* NULL Function Name */
2861#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */
2862#define SQLITE_COPY 0 /* No longer used */
2863#define SQLITE_RECURSIVE 33 /* NULL NULL */
2864
2865/*
2866** CAPI3REF: Tracing And Profiling Functions
2867** METHOD: sqlite3
2868**
2869** These routines are deprecated. Use the [sqlite3_trace_v2()] interface
2870** instead of the routines described here.
2871**
2872** These routines register callback functions that can be used for
2873** tracing and profiling the execution of SQL statements.
2874**
2875** ^The callback function registered by sqlite3_trace() is invoked at
2876** various times when an SQL statement is being run by [sqlite3_step()].
2877** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
2878** SQL statement text as the statement first begins executing.
2879** ^(Additional sqlite3_trace() callbacks might occur
2880** as each triggered subprogram is entered. The callbacks for triggers
2881** contain a UTF-8 SQL comment that identifies the trigger.)^
2882**
2883** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit
2884** the length of [bound parameter] expansion in the output of sqlite3_trace().
2885**
2886** ^The callback function registered by sqlite3_profile() is invoked
2887** as each SQL statement finishes. ^The profile callback contains
2888** the original statement text and an estimate of wall-clock time
2889** of how long that statement took to run. ^The profile callback
2890** time is in units of nanoseconds, however the current implementation
2891** is only capable of millisecond resolution so the six least significant
2892** digits in the time are meaningless. Future versions of SQLite
2893** might provide greater resolution on the profiler callback. The
2894** sqlite3_profile() function is considered experimental and is
2895** subject to change in future versions of SQLite.
2896*/
2897SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*,
2898 void(*xTrace)(void*,const char*), void*);
2899SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*,
2900 void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
2901
2902/*
2903** CAPI3REF: SQL Trace Event Codes
2904** KEYWORDS: SQLITE_TRACE
2905**
2906** These constants identify classes of events that can be monitored
2907** using the [sqlite3_trace_v2()] tracing logic. The M argument
2908** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of
2909** the following constants. ^The first argument to the trace callback
2910** is one of the following constants.
2911**
2912** New tracing constants may be added in future releases.
2913**
2914** ^A trace callback has four arguments: xCallback(T,C,P,X).
2915** ^The T argument is one of the integer type codes above.
2916** ^The C argument is a copy of the context pointer passed in as the
2917** fourth argument to [sqlite3_trace_v2()].
2918** The P and X arguments are pointers whose meanings depend on T.
2919**
2920** <dl>
2921** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt>
2922** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement
2923** first begins running and possibly at other times during the
2924** execution of the prepared statement, such as at the start of each
2925** trigger subprogram. ^The P argument is a pointer to the
2926** [prepared statement]. ^The X argument is a pointer to a string which
2927** is the unexpanded SQL text of the prepared statement or an SQL comment
2928** that indicates the invocation of a trigger. ^The callback can compute
2929** the same text that would have been returned by the legacy [sqlite3_trace()]
2930** interface by using the X argument when X begins with "--" and invoking
2931** [sqlite3_expanded_sql(P)] otherwise.
2932**
2933** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt>
2934** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same
2935** information as is provided by the [sqlite3_profile()] callback.
2936** ^The P argument is a pointer to the [prepared statement] and the
2937** X argument points to a 64-bit integer which is the estimated of
2938** the number of nanosecond that the prepared statement took to run.
2939** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes.
2940**
2941** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt>
2942** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared
2943** statement generates a single row of result.
2944** ^The P argument is a pointer to the [prepared statement] and the
2945** X argument is unused.
2946**
2947** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt>
2948** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database
2949** connection closes.
2950** ^The P argument is a pointer to the [database connection] object
2951** and the X argument is unused.
2952** </dl>
2953*/
2954#define SQLITE_TRACE_STMT 0x01
2955#define SQLITE_TRACE_PROFILE 0x02
2956#define SQLITE_TRACE_ROW 0x04
2957#define SQLITE_TRACE_CLOSE 0x08
2958
2959/*
2960** CAPI3REF: SQL Trace Hook
2961** METHOD: sqlite3
2962**
2963** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback
2964** function X against [database connection] D, using property mask M
2965** and context pointer P. ^If the X callback is
2966** NULL or if the M mask is zero, then tracing is disabled. The
2967** M argument should be the bitwise OR-ed combination of
2968** zero or more [SQLITE_TRACE] constants.
2969**
2970** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides
2971** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2().
2972**
2973** ^The X callback is invoked whenever any of the events identified by
2974** mask M occur. ^The integer return value from the callback is currently
2975** ignored, though this may change in future releases. Callback
2976** implementations should return zero to ensure future compatibility.
2977**
2978** ^A trace callback is invoked with four arguments: callback(T,C,P,X).
2979** ^The T argument is one of the [SQLITE_TRACE]
2980** constants to indicate why the callback was invoked.
2981** ^The C argument is a copy of the context pointer.
2982** The P and X arguments are pointers whose meanings depend on T.
2983**
2984** The sqlite3_trace_v2() interface is intended to replace the legacy
2985** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which
2986** are deprecated.
2987*/
2988SQLITE_API int sqlite3_trace_v2(
2989 sqlite3*,
2990 unsigned uMask,
2991 int(*xCallback)(unsigned,void*,void*,void*),
2992 void *pCtx
2993);
2994
2995/*
2996** CAPI3REF: Query Progress Callbacks
2997** METHOD: sqlite3
2998**
2999** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
3000** function X to be invoked periodically during long running calls to
3001** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for
3002** database connection D. An example use for this
3003** interface is to keep a GUI updated during a large query.
3004**
3005** ^The parameter P is passed through as the only parameter to the
3006** callback function X. ^The parameter N is the approximate number of
3007** [virtual machine instructions] that are evaluated between successive
3008** invocations of the callback X. ^If N is less than one then the progress
3009** handler is disabled.
3010**
3011** ^Only a single progress handler may be defined at one time per
3012** [database connection]; setting a new progress handler cancels the
3013** old one. ^Setting parameter X to NULL disables the progress handler.
3014** ^The progress handler is also disabled by setting N to a value less
3015** than 1.
3016**
3017** ^If the progress callback returns non-zero, the operation is
3018** interrupted. This feature can be used to implement a
3019** "Cancel" button on a GUI progress dialog box.
3020**
3021** The progress handler callback must not do anything that will modify
3022** the database connection that invoked the progress handler.
3023** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3024** database connections for the meaning of "modify" in this paragraph.
3025**
3026*/
3027SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
3028
3029/*
3030** CAPI3REF: Opening A New Database Connection
3031** CONSTRUCTOR: sqlite3
3032**
3033** ^These routines open an SQLite database file as specified by the
3034** filename argument. ^The filename argument is interpreted as UTF-8 for
3035** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
3036** order for sqlite3_open16(). ^(A [database connection] handle is usually
3037** returned in *ppDb, even if an error occurs. The only exception is that
3038** if SQLite is unable to allocate memory to hold the [sqlite3] object,
3039** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
3040** object.)^ ^(If the database is opened (and/or created) successfully, then
3041** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The
3042** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
3043** an English language description of the error following a failure of any
3044** of the sqlite3_open() routines.
3045**
3046** ^The default encoding will be UTF-8 for databases created using
3047** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases
3048** created using sqlite3_open16() will be UTF-16 in the native byte order.
3049**
3050** Whether or not an error occurs when it is opened, resources
3051** associated with the [database connection] handle should be released by
3052** passing it to [sqlite3_close()] when it is no longer required.
3053**
3054** The sqlite3_open_v2() interface works like sqlite3_open()
3055** except that it accepts two additional parameters for additional control
3056** over the new database connection. ^(The flags parameter to
3057** sqlite3_open_v2() can take one of
3058** the following three values, optionally combined with the
3059** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE],
3060** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^
3061**
3062** <dl>
3063** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
3064** <dd>The database is opened in read-only mode. If the database does not
3065** already exist, an error is returned.</dd>)^
3066**
3067** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
3068** <dd>The database is opened for reading and writing if possible, or reading
3069** only if the file is write protected by the operating system. In either
3070** case the database must already exist, otherwise an error is returned.</dd>)^
3071**
3072** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
3073** <dd>The database is opened for reading and writing, and is created if
3074** it does not already exist. This is the behavior that is always used for
3075** sqlite3_open() and sqlite3_open16().</dd>)^
3076** </dl>
3077**
3078** If the 3rd parameter to sqlite3_open_v2() is not one of the
3079** combinations shown above optionally combined with other
3080** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits]
3081** then the behavior is undefined.
3082**
3083** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection
3084** opens in the multi-thread [threading mode] as long as the single-thread
3085** mode has not been set at compile-time or start-time. ^If the
3086** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens
3087** in the serialized [threading mode] unless single-thread was
3088** previously selected at compile-time or start-time.
3089** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be
3090** eligible to use [shared cache mode], regardless of whether or not shared
3091** cache is enabled using [sqlite3_enable_shared_cache()]. ^The
3092** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not
3093** participate in [shared cache mode] even if it is enabled.
3094**
3095** ^The fourth parameter to sqlite3_open_v2() is the name of the
3096** [sqlite3_vfs] object that defines the operating system interface that
3097** the new database connection should use. ^If the fourth parameter is
3098** a NULL pointer then the default [sqlite3_vfs] object is used.
3099**
3100** ^If the filename is ":memory:", then a private, temporary in-memory database
3101** is created for the connection. ^This in-memory database will vanish when
3102** the database connection is closed. Future versions of SQLite might
3103** make use of additional special filenames that begin with the ":" character.
3104** It is recommended that when a database filename actually does begin with
3105** a ":" character you should prefix the filename with a pathname such as
3106** "./" to avoid ambiguity.
3107**
3108** ^If the filename is an empty string, then a private, temporary
3109** on-disk database will be created. ^This private database will be
3110** automatically deleted as soon as the database connection is closed.
3111**
3112** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
3113**
3114** ^If [URI filename] interpretation is enabled, and the filename argument
3115** begins with "file:", then the filename is interpreted as a URI. ^URI
3116** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
3117** set in the third argument to sqlite3_open_v2(), or if it has
3118** been enabled globally using the [SQLITE_CONFIG_URI] option with the
3119** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
3120** URI filename interpretation is turned off
3121** by default, but future releases of SQLite might enable URI filename
3122** interpretation by default. See "[URI filenames]" for additional
3123** information.
3124**
3125** URI filenames are parsed according to RFC 3986. ^If the URI contains an
3126** authority, then it must be either an empty string or the string
3127** "localhost". ^If the authority is not an empty string or "localhost", an
3128** error is returned to the caller. ^The fragment component of a URI, if
3129** present, is ignored.
3130**
3131** ^SQLite uses the path component of the URI as the name of the disk file
3132** which contains the database. ^If the path begins with a '/' character,
3133** then it is interpreted as an absolute path. ^If the path does not begin
3134** with a '/' (meaning that the authority section is omitted from the URI)
3135** then the path is interpreted as a relative path.
3136** ^(On windows, the first component of an absolute path
3137** is a drive specification (e.g. "C:").)^
3138**
3139** [[core URI query parameters]]
3140** The query component of a URI may contain parameters that are interpreted
3141** either by SQLite itself, or by a [VFS | custom VFS implementation].
3142** SQLite and its built-in [VFSes] interpret the
3143** following query parameters:
3144**
3145** <ul>
3146** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
3147** a VFS object that provides the operating system interface that should
3148** be used to access the database file on disk. ^If this option is set to
3149** an empty string the default VFS object is used. ^Specifying an unknown
3150** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
3151** present, then the VFS specified by the option takes precedence over
3152** the value passed as the fourth parameter to sqlite3_open_v2().
3153**
3154** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw",
3155** "rwc", or "memory". Attempting to set it to any other value is
3156** an error)^.
3157** ^If "ro" is specified, then the database is opened for read-only
3158** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the
3159** third argument to sqlite3_open_v2(). ^If the mode option is set to
3160** "rw", then the database is opened for read-write (but not create)
3161** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had
3162** been set. ^Value "rwc" is equivalent to setting both
3163** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is
3164** set to "memory" then a pure [in-memory database] that never reads
3165** or writes from disk is used. ^It is an error to specify a value for
3166** the mode parameter that is less restrictive than that specified by
3167** the flags passed in the third parameter to sqlite3_open_v2().
3168**
3169** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
3170** "private". ^Setting it to "shared" is equivalent to setting the
3171** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
3172** sqlite3_open_v2(). ^Setting the cache parameter to "private" is
3173** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
3174** ^If sqlite3_open_v2() is used and the "cache" parameter is present in
3175** a URI filename, its value overrides any behavior requested by setting
3176** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
3177**
3178** <li> <b>psow</b>: ^The psow parameter indicates whether or not the
3179** [powersafe overwrite] property does or does not apply to the
3180** storage media on which the database file resides.
3181**
3182** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter
3183** which if set disables file locking in rollback journal modes. This
3184** is useful for accessing a database on a filesystem that does not
3185** support locking. Caution: Database corruption might result if two
3186** or more processes write to the same database and any one of those
3187** processes uses nolock=1.
3188**
3189** <li> <b>immutable</b>: ^The immutable parameter is a boolean query
3190** parameter that indicates that the database file is stored on
3191** read-only media. ^When immutable is set, SQLite assumes that the
3192** database file cannot be changed, even by a process with higher
3193** privilege, and so the database is opened read-only and all locking
3194** and change detection is disabled. Caution: Setting the immutable
3195** property on a database file that does in fact change can result
3196** in incorrect query results and/or [SQLITE_CORRUPT] errors.
3197** See also: [SQLITE_IOCAP_IMMUTABLE].
3198**
3199** </ul>
3200**
3201** ^Specifying an unknown parameter in the query component of a URI is not an
3202** error. Future versions of SQLite might understand additional query
3203** parameters. See "[query parameters with special meaning to SQLite]" for
3204** additional information.
3205**
3206** [[URI filename examples]] <h3>URI filename examples</h3>
3207**
3208** <table border="1" align=center cellpadding=5>
3209** <tr><th> URI filenames <th> Results
3210** <tr><td> file:data.db <td>
3211** Open the file "data.db" in the current directory.
3212** <tr><td> file:/home/fred/data.db<br>
3213** file:///home/fred/data.db <br>
3214** file://localhost/home/fred/data.db <br> <td>
3215** Open the database file "/home/fred/data.db".
3216** <tr><td> file://darkstar/home/fred/data.db <td>
3217** An error. "darkstar" is not a recognized authority.
3218** <tr><td style="white-space:nowrap">
3219** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
3220** <td> Windows only: Open the file "data.db" on fred's desktop on drive
3221** C:. Note that the %20 escaping in this example is not strictly
3222** necessary - space characters can be used literally
3223** in URI filenames.
3224** <tr><td> file:data.db?mode=ro&cache=private <td>
3225** Open file "data.db" in the current directory for read-only access.
3226** Regardless of whether or not shared-cache mode is enabled by
3227** default, use a private cache.
3228** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td>
3229** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile"
3230** that uses dot-files in place of posix advisory locking.
3231** <tr><td> file:data.db?mode=readonly <td>
3232** An error. "readonly" is not a valid option for the "mode" parameter.
3233** </table>
3234**
3235** ^URI hexadecimal escape sequences (%HH) are supported within the path and
3236** query components of a URI. A hexadecimal escape sequence consists of a
3237** percent sign - "%" - followed by exactly two hexadecimal digits
3238** specifying an octet value. ^Before the path or query components of a
3239** URI filename are interpreted, they are encoded using UTF-8 and all
3240** hexadecimal escape sequences replaced by a single byte containing the
3241** corresponding octet. If this process generates an invalid UTF-8 encoding,
3242** the results are undefined.
3243**
3244** <b>Note to Windows users:</b> The encoding used for the filename argument
3245** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
3246** codepage is currently defined. Filenames containing international
3247** characters must be converted to UTF-8 prior to passing them into
3248** sqlite3_open() or sqlite3_open_v2().
3249**
3250** <b>Note to Windows Runtime users:</b> The temporary directory must be set
3251** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various
3252** features that require the use of temporary files may fail.
3253**
3254** See also: [sqlite3_temp_directory]
3255*/
3256SQLITE_API int sqlite3_open(
3257 const char *filename, /* Database filename (UTF-8) */
3258 sqlite3 **ppDb /* OUT: SQLite db handle */
3259);
3260SQLITE_API int sqlite3_open16(
3261 const void *filename, /* Database filename (UTF-16) */
3262 sqlite3 **ppDb /* OUT: SQLite db handle */
3263);
3264SQLITE_API int sqlite3_open_v2(
3265 const char *filename, /* Database filename (UTF-8) */
3266 sqlite3 **ppDb, /* OUT: SQLite db handle */
3267 int flags, /* Flags */
3268 const char *zVfs /* Name of VFS module to use */
3269);
3270
3271/*
3272** CAPI3REF: Obtain Values For URI Parameters
3273**
3274** These are utility routines, useful to VFS implementations, that check
3275** to see if a database file was a URI that contained a specific query
3276** parameter, and if so obtains the value of that query parameter.
3277**
3278** If F is the database filename pointer passed into the xOpen() method of
3279** a VFS implementation when the flags parameter to xOpen() has one or
3280** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and
3281** P is the name of the query parameter, then
3282** sqlite3_uri_parameter(F,P) returns the value of the P
3283** parameter if it exists or a NULL pointer if P does not appear as a
3284** query parameter on F. If P is a query parameter of F
3285** has no explicit value, then sqlite3_uri_parameter(F,P) returns
3286** a pointer to an empty string.
3287**
3288** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean
3289** parameter and returns true (1) or false (0) according to the value
3290** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the
3291** value of query parameter P is one of "yes", "true", or "on" in any
3292** case or if the value begins with a non-zero number. The
3293** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of
3294** query parameter P is one of "no", "false", or "off" in any case or
3295** if the value begins with a numeric zero. If P is not a query
3296** parameter on F or if the value of P is does not match any of the
3297** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0).
3298**
3299** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a
3300** 64-bit signed integer and returns that integer, or D if P does not
3301** exist. If the value of P is something other than an integer, then
3302** zero is returned.
3303**
3304** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and
3305** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and
3306** is not a database file pathname pointer that SQLite passed into the xOpen
3307** VFS method, then the behavior of this routine is undefined and probably
3308** undesirable.
3309*/
3310SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam);
3311SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault);
3312SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64);
3313
3314
3315/*
3316** CAPI3REF: Error Codes And Messages
3317** METHOD: sqlite3
3318**
3319** ^If the most recent sqlite3_* API call associated with
3320** [database connection] D failed, then the sqlite3_errcode(D) interface
3321** returns the numeric [result code] or [extended result code] for that
3322** API call.
3323** If the most recent API call was successful,
3324** then the return value from sqlite3_errcode() is undefined.
3325** ^The sqlite3_extended_errcode()
3326** interface is the same except that it always returns the
3327** [extended result code] even when extended result codes are
3328** disabled.
3329**
3330** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
3331** text that describes the error, as either UTF-8 or UTF-16 respectively.
3332** ^(Memory to hold the error message string is managed internally.
3333** The application does not need to worry about freeing the result.
3334** However, the error string might be overwritten or deallocated by
3335** subsequent calls to other SQLite interface functions.)^
3336**
3337** ^The sqlite3_errstr() interface returns the English-language text
3338** that describes the [result code], as UTF-8.
3339** ^(Memory to hold the error message string is managed internally
3340** and must not be freed by the application)^.
3341**
3342** When the serialized [threading mode] is in use, it might be the
3343** case that a second error occurs on a separate thread in between
3344** the time of the first error and the call to these interfaces.
3345** When that happens, the second error will be reported since these
3346** interfaces always report the most recent result. To avoid
3347** this, each thread can obtain exclusive use of the [database connection] D
3348** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
3349** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
3350** all calls to the interfaces listed here are completed.
3351**
3352** If an interface fails with SQLITE_MISUSE, that means the interface
3353** was invoked incorrectly by the application. In that case, the
3354** error code and message may or may not be set.
3355*/
3356SQLITE_API int sqlite3_errcode(sqlite3 *db);
3357SQLITE_API int sqlite3_extended_errcode(sqlite3 *db);
3358SQLITE_API const char *sqlite3_errmsg(sqlite3*);
3359SQLITE_API const void *sqlite3_errmsg16(sqlite3*);
3360SQLITE_API const char *sqlite3_errstr(int);
3361
3362/*
3363** CAPI3REF: Prepared Statement Object
3364** KEYWORDS: {prepared statement} {prepared statements}
3365**
3366** An instance of this object represents a single SQL statement that
3367** has been compiled into binary form and is ready to be evaluated.
3368**
3369** Think of each SQL statement as a separate computer program. The
3370** original SQL text is source code. A prepared statement object
3371** is the compiled object code. All SQL must be converted into a
3372** prepared statement before it can be run.
3373**
3374** The life-cycle of a prepared statement object usually goes like this:
3375**
3376** <ol>
3377** <li> Create the prepared statement object using [sqlite3_prepare_v2()].
3378** <li> Bind values to [parameters] using the sqlite3_bind_*()
3379** interfaces.
3380** <li> Run the SQL by calling [sqlite3_step()] one or more times.
3381** <li> Reset the prepared statement using [sqlite3_reset()] then go back
3382** to step 2. Do this zero or more times.
3383** <li> Destroy the object using [sqlite3_finalize()].
3384** </ol>
3385*/
3386typedef struct sqlite3_stmt sqlite3_stmt;
3387
3388/*
3389** CAPI3REF: Run-time Limits
3390** METHOD: sqlite3
3391**
3392** ^(This interface allows the size of various constructs to be limited
3393** on a connection by connection basis. The first parameter is the
3394** [database connection] whose limit is to be set or queried. The
3395** second parameter is one of the [limit categories] that define a
3396** class of constructs to be size limited. The third parameter is the
3397** new limit for that construct.)^
3398**
3399** ^If the new limit is a negative number, the limit is unchanged.
3400** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a
3401** [limits | hard upper bound]
3402** set at compile-time by a C preprocessor macro called
3403** [limits | SQLITE_MAX_<i>NAME</i>].
3404** (The "_LIMIT_" in the name is changed to "_MAX_".))^
3405** ^Attempts to increase a limit above its hard upper bound are
3406** silently truncated to the hard upper bound.
3407**
3408** ^Regardless of whether or not the limit was changed, the
3409** [sqlite3_limit()] interface returns the prior value of the limit.
3410** ^Hence, to find the current value of a limit without changing it,
3411** simply invoke this interface with the third parameter set to -1.
3412**
3413** Run-time limits are intended for use in applications that manage
3414** both their own internal database and also databases that are controlled
3415** by untrusted external sources. An example application might be a
3416** web browser that has its own databases for storing history and
3417** separate databases controlled by JavaScript applications downloaded
3418** off the Internet. The internal databases can be given the
3419** large, default limits. Databases managed by external sources can
3420** be given much smaller limits designed to prevent a denial of service
3421** attack. Developers might also want to use the [sqlite3_set_authorizer()]
3422** interface to further control untrusted SQL. The size of the database
3423** created by an untrusted script can be contained using the
3424** [max_page_count] [PRAGMA].
3425**
3426** New run-time limit categories may be added in future releases.
3427*/
3428SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
3429
3430/*
3431** CAPI3REF: Run-Time Limit Categories
3432** KEYWORDS: {limit category} {*limit categories}
3433**
3434** These constants define various performance limits
3435** that can be lowered at run-time using [sqlite3_limit()].
3436** The synopsis of the meanings of the various limits is shown below.
3437** Additional information is available at [limits | Limits in SQLite].
3438**
3439** <dl>
3440** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
3441** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
3442**
3443** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
3444** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
3445**
3446** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt>
3447** <dd>The maximum number of columns in a table definition or in the
3448** result set of a [SELECT] or the maximum number of columns in an index
3449** or in an ORDER BY or GROUP BY clause.</dd>)^
3450**
3451** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
3452** <dd>The maximum depth of the parse tree on any expression.</dd>)^
3453**
3454** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
3455** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
3456**
3457** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
3458** <dd>The maximum number of instructions in a virtual machine program
3459** used to implement an SQL statement. If [sqlite3_prepare_v2()] or
3460** the equivalent tries to allocate space for more than this many opcodes
3461** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^
3462**
3463** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
3464** <dd>The maximum number of arguments on a function.</dd>)^
3465**
3466** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
3467** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
3468**
3469** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]]
3470** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
3471** <dd>The maximum length of the pattern argument to the [LIKE] or
3472** [GLOB] operators.</dd>)^
3473**
3474** [[SQLITE_LIMIT_VARIABLE_NUMBER]]
3475** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
3476** <dd>The maximum index number of any [parameter] in an SQL statement.)^
3477**
3478** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
3479** <dd>The maximum depth of recursion for triggers.</dd>)^
3480**
3481** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt>
3482** <dd>The maximum number of auxiliary worker threads that a single
3483** [prepared statement] may start.</dd>)^
3484** </dl>
3485*/
3486#define SQLITE_LIMIT_LENGTH 0
3487#define SQLITE_LIMIT_SQL_LENGTH 1
3488#define SQLITE_LIMIT_COLUMN 2
3489#define SQLITE_LIMIT_EXPR_DEPTH 3
3490#define SQLITE_LIMIT_COMPOUND_SELECT 4
3491#define SQLITE_LIMIT_VDBE_OP 5
3492#define SQLITE_LIMIT_FUNCTION_ARG 6
3493#define SQLITE_LIMIT_ATTACHED 7
3494#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8
3495#define SQLITE_LIMIT_VARIABLE_NUMBER 9
3496#define SQLITE_LIMIT_TRIGGER_DEPTH 10
3497#define SQLITE_LIMIT_WORKER_THREADS 11
3498
3499/*
3500** CAPI3REF: Prepare Flags
3501**
3502** These constants define various flags that can be passed into
3503** "prepFlags" parameter of the [sqlite3_prepare_v3()] and
3504** [sqlite3_prepare16_v3()] interfaces.
3505**
3506** New flags may be added in future releases of SQLite.
3507**
3508** <dl>
3509** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt>
3510** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner
3511** that the prepared statement will be retained for a long time and
3512** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()]
3513** and [sqlite3_prepare16_v3()] assume that the prepared statement will
3514** be used just once or at most a few times and then destroyed using
3515** [sqlite3_finalize()] relatively soon. The current implementation acts
3516** on this hint by avoiding the use of [lookaside memory] so as not to
3517** deplete the limited store of lookaside memory. Future versions of
3518** SQLite may act on this hint differently.
3519** </dl>
3520*/
3521#define SQLITE_PREPARE_PERSISTENT 0x01
3522
3523/*
3524** CAPI3REF: Compiling An SQL Statement
3525** KEYWORDS: {SQL statement compiler}
3526** METHOD: sqlite3
3527** CONSTRUCTOR: sqlite3_stmt
3528**
3529** To execute an SQL statement, it must first be compiled into a byte-code
3530** program using one of these routines. Or, in other words, these routines
3531** are constructors for the [prepared statement] object.
3532**
3533** The preferred routine to use is [sqlite3_prepare_v2()]. The
3534** [sqlite3_prepare()] interface is legacy and should be avoided.
3535** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used
3536** for special purposes.
3537**
3538** The use of the UTF-8 interfaces is preferred, as SQLite currently
3539** does all parsing using UTF-8. The UTF-16 interfaces are provided
3540** as a convenience. The UTF-16 interfaces work by converting the
3541** input text into UTF-8, then invoking the corresponding UTF-8 interface.
3542**
3543** The first argument, "db", is a [database connection] obtained from a
3544** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
3545** [sqlite3_open16()]. The database connection must not have been closed.
3546**
3547** The second argument, "zSql", is the statement to be compiled, encoded
3548** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(),
3549** and sqlite3_prepare_v3()
3550** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(),
3551** and sqlite3_prepare16_v3() use UTF-16.
3552**
3553** ^If the nByte argument is negative, then zSql is read up to the
3554** first zero terminator. ^If nByte is positive, then it is the
3555** number of bytes read from zSql. ^If nByte is zero, then no prepared
3556** statement is generated.
3557** If the caller knows that the supplied string is nul-terminated, then
3558** there is a small performance advantage to passing an nByte parameter that
3559** is the number of bytes in the input string <i>including</i>
3560** the nul-terminator.
3561**
3562** ^If pzTail is not NULL then *pzTail is made to point to the first byte
3563** past the end of the first SQL statement in zSql. These routines only
3564** compile the first statement in zSql, so *pzTail is left pointing to
3565** what remains uncompiled.
3566**
3567** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
3568** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set
3569** to NULL. ^If the input text contains no SQL (if the input is an empty
3570** string or a comment) then *ppStmt is set to NULL.
3571** The calling procedure is responsible for deleting the compiled
3572** SQL statement using [sqlite3_finalize()] after it has finished with it.
3573** ppStmt may not be NULL.
3574**
3575** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
3576** otherwise an [error code] is returned.
3577**
3578** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(),
3579** and sqlite3_prepare16_v3() interfaces are recommended for all new programs.
3580** The older interfaces (sqlite3_prepare() and sqlite3_prepare16())
3581** are retained for backwards compatibility, but their use is discouraged.
3582** ^In the "vX" interfaces, the prepared statement
3583** that is returned (the [sqlite3_stmt] object) contains a copy of the
3584** original SQL text. This causes the [sqlite3_step()] interface to
3585** behave differently in three ways:
3586**
3587** <ol>
3588** <li>
3589** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
3590** always used to do, [sqlite3_step()] will automatically recompile the SQL
3591** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY]
3592** retries will occur before sqlite3_step() gives up and returns an error.
3593** </li>
3594**
3595** <li>
3596** ^When an error occurs, [sqlite3_step()] will return one of the detailed
3597** [error codes] or [extended error codes]. ^The legacy behavior was that
3598** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
3599** and the application would have to make a second call to [sqlite3_reset()]
3600** in order to find the underlying cause of the problem. With the "v2" prepare
3601** interfaces, the underlying reason for the error is returned immediately.
3602** </li>
3603**
3604** <li>
3605** ^If the specific value bound to [parameter | host parameter] in the
3606** WHERE clause might influence the choice of query plan for a statement,
3607** then the statement will be automatically recompiled, as if there had been
3608** a schema change, on the first [sqlite3_step()] call following any change
3609** to the [sqlite3_bind_text | bindings] of that [parameter].
3610** ^The specific value of WHERE-clause [parameter] might influence the
3611** choice of query plan if the parameter is the left-hand side of a [LIKE]
3612** or [GLOB] operator or if the parameter is compared to an indexed column
3613** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled.
3614** </li>
3615** </ol>
3616**
3617** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having
3618** the extra prepFlags parameter, which is a bit array consisting of zero or
3619** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The
3620** sqlite3_prepare_v2() interface works exactly the same as
3621** sqlite3_prepare_v3() with a zero prepFlags parameter.
3622*/
3623SQLITE_API int sqlite3_prepare(
3624 sqlite3 *db, /* Database handle */
3625 const char *zSql, /* SQL statement, UTF-8 encoded */
3626 int nByte, /* Maximum length of zSql in bytes. */
3627 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3628 const char **pzTail /* OUT: Pointer to unused portion of zSql */
3629);
3630SQLITE_API int sqlite3_prepare_v2(
3631 sqlite3 *db, /* Database handle */
3632 const char *zSql, /* SQL statement, UTF-8 encoded */
3633 int nByte, /* Maximum length of zSql in bytes. */
3634 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3635 const char **pzTail /* OUT: Pointer to unused portion of zSql */
3636);
3637SQLITE_API int sqlite3_prepare_v3(
3638 sqlite3 *db, /* Database handle */
3639 const char *zSql, /* SQL statement, UTF-8 encoded */
3640 int nByte, /* Maximum length of zSql in bytes. */
3641 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
3642 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3643 const char **pzTail /* OUT: Pointer to unused portion of zSql */
3644);
3645SQLITE_API int sqlite3_prepare16(
3646 sqlite3 *db, /* Database handle */
3647 const void *zSql, /* SQL statement, UTF-16 encoded */
3648 int nByte, /* Maximum length of zSql in bytes. */
3649 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3650 const void **pzTail /* OUT: Pointer to unused portion of zSql */
3651);
3652SQLITE_API int sqlite3_prepare16_v2(
3653 sqlite3 *db, /* Database handle */
3654 const void *zSql, /* SQL statement, UTF-16 encoded */
3655 int nByte, /* Maximum length of zSql in bytes. */
3656 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3657 const void **pzTail /* OUT: Pointer to unused portion of zSql */
3658);
3659SQLITE_API int sqlite3_prepare16_v3(
3660 sqlite3 *db, /* Database handle */
3661 const void *zSql, /* SQL statement, UTF-16 encoded */
3662 int nByte, /* Maximum length of zSql in bytes. */
3663 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
3664 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3665 const void **pzTail /* OUT: Pointer to unused portion of zSql */
3666);
3667
3668/*
3669** CAPI3REF: Retrieving Statement SQL
3670** METHOD: sqlite3_stmt
3671**
3672** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8
3673** SQL text used to create [prepared statement] P if P was
3674** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()],
3675** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
3676** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8
3677** string containing the SQL text of prepared statement P with
3678** [bound parameters] expanded.
3679**
3680** ^(For example, if a prepared statement is created using the SQL
3681** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345
3682** and parameter :xyz is unbound, then sqlite3_sql() will return
3683** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql()
3684** will return "SELECT 2345,NULL".)^
3685**
3686** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory
3687** is available to hold the result, or if the result would exceed the
3688** the maximum string length determined by the [SQLITE_LIMIT_LENGTH].
3689**
3690** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of
3691** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time
3692** option causes sqlite3_expanded_sql() to always return NULL.
3693**
3694** ^The string returned by sqlite3_sql(P) is managed by SQLite and is
3695** automatically freed when the prepared statement is finalized.
3696** ^The string returned by sqlite3_expanded_sql(P), on the other hand,
3697** is obtained from [sqlite3_malloc()] and must be free by the application
3698** by passing it to [sqlite3_free()].
3699*/
3700SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt);
3701SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt);
3702
3703/*
3704** CAPI3REF: Determine If An SQL Statement Writes The Database
3705** METHOD: sqlite3_stmt
3706**
3707** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
3708** and only if the [prepared statement] X makes no direct changes to
3709** the content of the database file.
3710**
3711** Note that [application-defined SQL functions] or
3712** [virtual tables] might change the database indirectly as a side effect.
3713** ^(For example, if an application defines a function "eval()" that
3714** calls [sqlite3_exec()], then the following SQL statement would
3715** change the database file through side-effects:
3716**
3717** <blockquote><pre>
3718** SELECT eval('DELETE FROM t1') FROM t2;
3719** </pre></blockquote>
3720**
3721** But because the [SELECT] statement does not change the database file
3722** directly, sqlite3_stmt_readonly() would still return true.)^
3723**
3724** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
3725** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
3726** since the statements themselves do not actually modify the database but
3727** rather they control the timing of when other statements modify the
3728** database. ^The [ATTACH] and [DETACH] statements also cause
3729** sqlite3_stmt_readonly() to return true since, while those statements
3730** change the configuration of a database connection, they do not make
3731** changes to the content of the database files on disk.
3732** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since
3733** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and
3734** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so
3735** sqlite3_stmt_readonly() returns false for those commands.
3736*/
3737SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
3738
3739/*
3740** CAPI3REF: Determine If A Prepared Statement Has Been Reset
3741** METHOD: sqlite3_stmt
3742**
3743** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the
3744** [prepared statement] S has been stepped at least once using
3745** [sqlite3_step(S)] but has neither run to completion (returned
3746** [SQLITE_DONE] from [sqlite3_step(S)]) nor
3747** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S)
3748** interface returns false if S is a NULL pointer. If S is not a
3749** NULL pointer and is not a pointer to a valid [prepared statement]
3750** object, then the behavior is undefined and probably undesirable.
3751**
3752** This interface can be used in combination [sqlite3_next_stmt()]
3753** to locate all prepared statements associated with a database
3754** connection that are in need of being reset. This can be used,
3755** for example, in diagnostic routines to search for prepared
3756** statements that are holding a transaction open.
3757*/
3758SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*);
3759
3760/*
3761** CAPI3REF: Dynamically Typed Value Object
3762** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
3763**
3764** SQLite uses the sqlite3_value object to represent all values
3765** that can be stored in a database table. SQLite uses dynamic typing
3766** for the values it stores. ^Values stored in sqlite3_value objects
3767** can be integers, floating point values, strings, BLOBs, or NULL.
3768**
3769** An sqlite3_value object may be either "protected" or "unprotected".
3770** Some interfaces require a protected sqlite3_value. Other interfaces
3771** will accept either a protected or an unprotected sqlite3_value.
3772** Every interface that accepts sqlite3_value arguments specifies
3773** whether or not it requires a protected sqlite3_value. The
3774** [sqlite3_value_dup()] interface can be used to construct a new
3775** protected sqlite3_value from an unprotected sqlite3_value.
3776**
3777** The terms "protected" and "unprotected" refer to whether or not
3778** a mutex is held. An internal mutex is held for a protected
3779** sqlite3_value object but no mutex is held for an unprotected
3780** sqlite3_value object. If SQLite is compiled to be single-threaded
3781** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
3782** or if SQLite is run in one of reduced mutex modes
3783** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
3784** then there is no distinction between protected and unprotected
3785** sqlite3_value objects and they can be used interchangeably. However,
3786** for maximum code portability it is recommended that applications
3787** still make the distinction between protected and unprotected
3788** sqlite3_value objects even when not strictly required.
3789**
3790** ^The sqlite3_value objects that are passed as parameters into the
3791** implementation of [application-defined SQL functions] are protected.
3792** ^The sqlite3_value object returned by
3793** [sqlite3_column_value()] is unprotected.
3794** Unprotected sqlite3_value objects may only be used as arguments
3795** to [sqlite3_result_value()], [sqlite3_bind_value()], and
3796** [sqlite3_value_dup()].
3797** The [sqlite3_value_blob | sqlite3_value_type()] family of
3798** interfaces require protected sqlite3_value objects.
3799*/
3800typedef struct sqlite3_value sqlite3_value;
3801
3802/*
3803** CAPI3REF: SQL Function Context Object
3804**
3805** The context in which an SQL function executes is stored in an
3806** sqlite3_context object. ^A pointer to an sqlite3_context object
3807** is always first parameter to [application-defined SQL functions].
3808** The application-defined SQL function implementation will pass this
3809** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
3810** [sqlite3_aggregate_context()], [sqlite3_user_data()],
3811** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
3812** and/or [sqlite3_set_auxdata()].
3813*/
3814typedef struct sqlite3_context sqlite3_context;
3815
3816/*
3817** CAPI3REF: Binding Values To Prepared Statements
3818** KEYWORDS: {host parameter} {host parameters} {host parameter name}
3819** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
3820** METHOD: sqlite3_stmt
3821**
3822** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
3823** literals may be replaced by a [parameter] that matches one of following
3824** templates:
3825**
3826** <ul>
3827** <li> ?
3828** <li> ?NNN
3829** <li> :VVV
3830** <li> @VVV
3831** <li> $VVV
3832** </ul>
3833**
3834** In the templates above, NNN represents an integer literal,
3835** and VVV represents an alphanumeric identifier.)^ ^The values of these
3836** parameters (also called "host parameter names" or "SQL parameters")
3837** can be set using the sqlite3_bind_*() routines defined here.
3838**
3839** ^The first argument to the sqlite3_bind_*() routines is always
3840** a pointer to the [sqlite3_stmt] object returned from
3841** [sqlite3_prepare_v2()] or its variants.
3842**
3843** ^The second argument is the index of the SQL parameter to be set.
3844** ^The leftmost SQL parameter has an index of 1. ^When the same named
3845** SQL parameter is used more than once, second and subsequent
3846** occurrences have the same index as the first occurrence.
3847** ^The index for named parameters can be looked up using the
3848** [sqlite3_bind_parameter_index()] API if desired. ^The index
3849** for "?NNN" parameters is the value of NNN.
3850** ^The NNN value must be between 1 and the [sqlite3_limit()]
3851** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999).
3852**
3853** ^The third argument is the value to bind to the parameter.
3854** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16()
3855** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter
3856** is ignored and the end result is the same as sqlite3_bind_null().
3857**
3858** ^(In those routines that have a fourth argument, its value is the
3859** number of bytes in the parameter. To be clear: the value is the
3860** number of <u>bytes</u> in the value, not the number of characters.)^
3861** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16()
3862** is negative, then the length of the string is
3863** the number of bytes up to the first zero terminator.
3864** If the fourth parameter to sqlite3_bind_blob() is negative, then
3865** the behavior is undefined.
3866** If a non-negative fourth parameter is provided to sqlite3_bind_text()
3867** or sqlite3_bind_text16() or sqlite3_bind_text64() then
3868** that parameter must be the byte offset
3869** where the NUL terminator would occur assuming the string were NUL
3870** terminated. If any NUL characters occur at byte offsets less than
3871** the value of the fourth parameter then the resulting string value will
3872** contain embedded NULs. The result of expressions involving strings
3873** with embedded NULs is undefined.
3874**
3875** ^The fifth argument to the BLOB and string binding interfaces
3876** is a destructor used to dispose of the BLOB or
3877** string after SQLite has finished with it. ^The destructor is called
3878** to dispose of the BLOB or string even if the call to bind API fails.
3879** ^If the fifth argument is
3880** the special value [SQLITE_STATIC], then SQLite assumes that the
3881** information is in static, unmanaged space and does not need to be freed.
3882** ^If the fifth argument has the value [SQLITE_TRANSIENT], then
3883** SQLite makes its own private copy of the data immediately, before
3884** the sqlite3_bind_*() routine returns.
3885**
3886** ^The sixth argument to sqlite3_bind_text64() must be one of
3887** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]
3888** to specify the encoding of the text in the third parameter. If
3889** the sixth argument to sqlite3_bind_text64() is not one of the
3890** allowed values shown above, or if the text encoding is different
3891** from the encoding specified by the sixth parameter, then the behavior
3892** is undefined.
3893**
3894** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
3895** is filled with zeroes. ^A zeroblob uses a fixed amount of memory
3896** (just an integer to hold its size) while it is being processed.
3897** Zeroblobs are intended to serve as placeholders for BLOBs whose
3898** content is later written using
3899** [sqlite3_blob_open | incremental BLOB I/O] routines.
3900** ^A negative value for the zeroblob results in a zero-length BLOB.
3901**
3902** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in
3903** [prepared statement] S to have an SQL value of NULL, but to also be
3904** associated with the pointer P of type T. ^D is either a NULL pointer or
3905** a pointer to a destructor function for P. ^SQLite will invoke the
3906** destructor D with a single argument of P when it is finished using
3907** P. The T parameter should be a static string, preferably a string
3908** literal. The sqlite3_bind_pointer() routine is part of the
3909** [pointer passing interface] added for SQLite 3.20.0.
3910**
3911** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
3912** for the [prepared statement] or with a prepared statement for which
3913** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
3914** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_()
3915** routine is passed a [prepared statement] that has been finalized, the
3916** result is undefined and probably harmful.
3917**
3918** ^Bindings are not cleared by the [sqlite3_reset()] routine.
3919** ^Unbound parameters are interpreted as NULL.
3920**
3921** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
3922** [error code] if anything goes wrong.
3923** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB
3924** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or
3925** [SQLITE_MAX_LENGTH].
3926** ^[SQLITE_RANGE] is returned if the parameter
3927** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails.
3928**
3929** See also: [sqlite3_bind_parameter_count()],
3930** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
3931*/
3932SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
3933SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64,
3934 void(*)(void*));
3935SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double);
3936SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int);
3937SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
3938SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int);
3939SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*));
3940SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
3941SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64,
3942 void(*)(void*), unsigned char encoding);
3943SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
3944SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*));
3945SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
3946SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64);
3947
3948/*
3949** CAPI3REF: Number Of SQL Parameters
3950** METHOD: sqlite3_stmt
3951**
3952** ^This routine can be used to find the number of [SQL parameters]
3953** in a [prepared statement]. SQL parameters are tokens of the
3954** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
3955** placeholders for values that are [sqlite3_bind_blob | bound]
3956** to the parameters at a later time.
3957**
3958** ^(This routine actually returns the index of the largest (rightmost)
3959** parameter. For all forms except ?NNN, this will correspond to the
3960** number of unique parameters. If parameters of the ?NNN form are used,
3961** there may be gaps in the list.)^
3962**
3963** See also: [sqlite3_bind_blob|sqlite3_bind()],
3964** [sqlite3_bind_parameter_name()], and
3965** [sqlite3_bind_parameter_index()].
3966*/
3967SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);
3968
3969/*
3970** CAPI3REF: Name Of A Host Parameter
3971** METHOD: sqlite3_stmt
3972**
3973** ^The sqlite3_bind_parameter_name(P,N) interface returns
3974** the name of the N-th [SQL parameter] in the [prepared statement] P.
3975** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
3976** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
3977** respectively.
3978** In other words, the initial ":" or "$" or "@" or "?"
3979** is included as part of the name.)^
3980** ^Parameters of the form "?" without a following integer have no name
3981** and are referred to as "nameless" or "anonymous parameters".
3982**
3983** ^The first host parameter has an index of 1, not 0.
3984**
3985** ^If the value N is out of range or if the N-th parameter is
3986** nameless, then NULL is returned. ^The returned string is
3987** always in UTF-8 encoding even if the named parameter was
3988** originally specified as UTF-16 in [sqlite3_prepare16()],
3989** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
3990**
3991** See also: [sqlite3_bind_blob|sqlite3_bind()],
3992** [sqlite3_bind_parameter_count()], and
3993** [sqlite3_bind_parameter_index()].
3994*/
3995SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
3996
3997/*
3998** CAPI3REF: Index Of A Parameter With A Given Name
3999** METHOD: sqlite3_stmt
4000**
4001** ^Return the index of an SQL parameter given its name. ^The
4002** index value returned is suitable for use as the second
4003** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero
4004** is returned if no matching parameter is found. ^The parameter
4005** name must be given in UTF-8 even if the original statement
4006** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or
4007** [sqlite3_prepare16_v3()].
4008**
4009** See also: [sqlite3_bind_blob|sqlite3_bind()],
4010** [sqlite3_bind_parameter_count()], and
4011** [sqlite3_bind_parameter_name()].
4012*/
4013SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
4014
4015/*
4016** CAPI3REF: Reset All Bindings On A Prepared Statement
4017** METHOD: sqlite3_stmt
4018**
4019** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
4020** the [sqlite3_bind_blob | bindings] on a [prepared statement].
4021** ^Use this routine to reset all host parameters to NULL.
4022*/
4023SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);
4024
4025/*
4026** CAPI3REF: Number Of Columns In A Result Set
4027** METHOD: sqlite3_stmt
4028**
4029** ^Return the number of columns in the result set returned by the
4030** [prepared statement]. ^If this routine returns 0, that means the
4031** [prepared statement] returns no data (for example an [UPDATE]).
4032** ^However, just because this routine returns a positive number does not
4033** mean that one or more rows of data will be returned. ^A SELECT statement
4034** will always have a positive sqlite3_column_count() but depending on the
4035** WHERE clause constraints and the table content, it might return no rows.
4036**
4037** See also: [sqlite3_data_count()]
4038*/
4039SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt);
4040
4041/*
4042** CAPI3REF: Column Names In A Result Set
4043** METHOD: sqlite3_stmt
4044**
4045** ^These routines return the name assigned to a particular column
4046** in the result set of a [SELECT] statement. ^The sqlite3_column_name()
4047** interface returns a pointer to a zero-terminated UTF-8 string
4048** and sqlite3_column_name16() returns a pointer to a zero-terminated
4049** UTF-16 string. ^The first parameter is the [prepared statement]
4050** that implements the [SELECT] statement. ^The second parameter is the
4051** column number. ^The leftmost column is number 0.
4052**
4053** ^The returned string pointer is valid until either the [prepared statement]
4054** is destroyed by [sqlite3_finalize()] or until the statement is automatically
4055** reprepared by the first call to [sqlite3_step()] for a particular run
4056** or until the next call to
4057** sqlite3_column_name() or sqlite3_column_name16() on the same column.
4058**
4059** ^If sqlite3_malloc() fails during the processing of either routine
4060** (for example during a conversion from UTF-8 to UTF-16) then a
4061** NULL pointer is returned.
4062**
4063** ^The name of a result column is the value of the "AS" clause for
4064** that column, if there is an AS clause. If there is no AS clause
4065** then the name of the column is unspecified and may change from
4066** one release of SQLite to the next.
4067*/
4068SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N);
4069SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N);
4070
4071/*
4072** CAPI3REF: Source Of Data In A Query Result
4073** METHOD: sqlite3_stmt
4074**
4075** ^These routines provide a means to determine the database, table, and
4076** table column that is the origin of a particular result column in
4077** [SELECT] statement.
4078** ^The name of the database or table or column can be returned as
4079** either a UTF-8 or UTF-16 string. ^The _database_ routines return
4080** the database name, the _table_ routines return the table name, and
4081** the origin_ routines return the column name.
4082** ^The returned string is valid until the [prepared statement] is destroyed
4083** using [sqlite3_finalize()] or until the statement is automatically
4084** reprepared by the first call to [sqlite3_step()] for a particular run
4085** or until the same information is requested
4086** again in a different encoding.
4087**
4088** ^The names returned are the original un-aliased names of the
4089** database, table, and column.
4090**
4091** ^The first argument to these interfaces is a [prepared statement].
4092** ^These functions return information about the Nth result column returned by
4093** the statement, where N is the second function argument.
4094** ^The left-most column is column 0 for these routines.
4095**
4096** ^If the Nth column returned by the statement is an expression or
4097** subquery and is not a column value, then all of these functions return
4098** NULL. ^These routine might also return NULL if a memory allocation error
4099** occurs. ^Otherwise, they return the name of the attached database, table,
4100** or column that query result column was extracted from.
4101**
4102** ^As with all other SQLite APIs, those whose names end with "16" return
4103** UTF-16 encoded strings and the other functions return UTF-8.
4104**
4105** ^These APIs are only available if the library was compiled with the
4106** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
4107**
4108** If two or more threads call one or more of these routines against the same
4109** prepared statement and column at the same time then the results are
4110** undefined.
4111**
4112** If two or more threads call one or more
4113** [sqlite3_column_database_name | column metadata interfaces]
4114** for the same [prepared statement] and result column
4115** at the same time then the results are undefined.
4116*/
4117SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int);
4118SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
4119SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int);
4120SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
4121SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
4122SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
4123
4124/*
4125** CAPI3REF: Declared Datatype Of A Query Result
4126** METHOD: sqlite3_stmt
4127**
4128** ^(The first parameter is a [prepared statement].
4129** If this statement is a [SELECT] statement and the Nth column of the
4130** returned result set of that [SELECT] is a table column (not an
4131** expression or subquery) then the declared type of the table
4132** column is returned.)^ ^If the Nth column of the result set is an
4133** expression or subquery, then a NULL pointer is returned.
4134** ^The returned string is always UTF-8 encoded.
4135**
4136** ^(For example, given the database schema:
4137**
4138** CREATE TABLE t1(c1 VARIANT);
4139**
4140** and the following statement to be compiled:
4141**
4142** SELECT c1 + 1, c1 FROM t1;
4143**
4144** this routine would return the string "VARIANT" for the second result
4145** column (i==1), and a NULL pointer for the first result column (i==0).)^
4146**
4147** ^SQLite uses dynamic run-time typing. ^So just because a column
4148** is declared to contain a particular type does not mean that the
4149** data stored in that column is of the declared type. SQLite is
4150** strongly typed, but the typing is dynamic not static. ^Type
4151** is associated with individual values, not with the containers
4152** used to hold those values.
4153*/
4154SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int);
4155SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
4156
4157/*
4158** CAPI3REF: Evaluate An SQL Statement
4159** METHOD: sqlite3_stmt
4160**
4161** After a [prepared statement] has been prepared using any of
4162** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()],
4163** or [sqlite3_prepare16_v3()] or one of the legacy
4164** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
4165** must be called one or more times to evaluate the statement.
4166**
4167** The details of the behavior of the sqlite3_step() interface depend
4168** on whether the statement was prepared using the newer "vX" interfaces
4169** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()],
4170** [sqlite3_prepare16_v2()] or the older legacy
4171** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the
4172** new "vX" interface is recommended for new applications but the legacy
4173** interface will continue to be supported.
4174**
4175** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
4176** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
4177** ^With the "v2" interface, any of the other [result codes] or
4178** [extended result codes] might be returned as well.
4179**
4180** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
4181** database locks it needs to do its job. ^If the statement is a [COMMIT]
4182** or occurs outside of an explicit transaction, then you can retry the
4183** statement. If the statement is not a [COMMIT] and occurs within an
4184** explicit transaction then you should rollback the transaction before
4185** continuing.
4186**
4187** ^[SQLITE_DONE] means that the statement has finished executing
4188** successfully. sqlite3_step() should not be called again on this virtual
4189** machine without first calling [sqlite3_reset()] to reset the virtual
4190** machine back to its initial state.
4191**
4192** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
4193** is returned each time a new row of data is ready for processing by the
4194** caller. The values may be accessed using the [column access functions].
4195** sqlite3_step() is called again to retrieve the next row of data.
4196**
4197** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
4198** violation) has occurred. sqlite3_step() should not be called again on
4199** the VM. More information may be found by calling [sqlite3_errmsg()].
4200** ^With the legacy interface, a more specific error code (for example,
4201** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
4202** can be obtained by calling [sqlite3_reset()] on the
4203** [prepared statement]. ^In the "v2" interface,
4204** the more specific error code is returned directly by sqlite3_step().
4205**
4206** [SQLITE_MISUSE] means that the this routine was called inappropriately.
4207** Perhaps it was called on a [prepared statement] that has
4208** already been [sqlite3_finalize | finalized] or on one that had
4209** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could
4210** be the case that the same database connection is being used by two or
4211** more threads at the same moment in time.
4212**
4213** For all versions of SQLite up to and including 3.6.23.1, a call to
4214** [sqlite3_reset()] was required after sqlite3_step() returned anything
4215** other than [SQLITE_ROW] before any subsequent invocation of
4216** sqlite3_step(). Failure to reset the prepared statement using
4217** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
4218** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1],
4219** sqlite3_step() began
4220** calling [sqlite3_reset()] automatically in this circumstance rather
4221** than returning [SQLITE_MISUSE]. This is not considered a compatibility
4222** break because any application that ever receives an SQLITE_MISUSE error
4223** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option
4224** can be used to restore the legacy behavior.
4225**
4226** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
4227** API always returns a generic error code, [SQLITE_ERROR], following any
4228** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call
4229** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
4230** specific [error codes] that better describes the error.
4231** We admit that this is a goofy design. The problem has been fixed
4232** with the "v2" interface. If you prepare all of your SQL statements
4233** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()]
4234** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead
4235** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
4236** then the more specific [error codes] are returned directly
4237** by sqlite3_step(). The use of the "vX" interfaces is recommended.
4238*/
4239SQLITE_API int sqlite3_step(sqlite3_stmt*);
4240
4241/*
4242** CAPI3REF: Number of columns in a result set
4243** METHOD: sqlite3_stmt
4244**
4245** ^The sqlite3_data_count(P) interface returns the number of columns in the
4246** current row of the result set of [prepared statement] P.
4247** ^If prepared statement P does not have results ready to return
4248** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of
4249** interfaces) then sqlite3_data_count(P) returns 0.
4250** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.
4251** ^The sqlite3_data_count(P) routine returns 0 if the previous call to
4252** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P)
4253** will return non-zero if previous call to [sqlite3_step](P) returned
4254** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum]
4255** where it always returns zero since each step of that multi-step
4256** pragma returns 0 columns of data.
4257**
4258** See also: [sqlite3_column_count()]
4259*/
4260SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
4261
4262/*
4263** CAPI3REF: Fundamental Datatypes
4264** KEYWORDS: SQLITE_TEXT
4265**
4266** ^(Every value in SQLite has one of five fundamental datatypes:
4267**
4268** <ul>
4269** <li> 64-bit signed integer
4270** <li> 64-bit IEEE floating point number
4271** <li> string
4272** <li> BLOB
4273** <li> NULL
4274** </ul>)^
4275**
4276** These constants are codes for each of those types.
4277**
4278** Note that the SQLITE_TEXT constant was also used in SQLite version 2
4279** for a completely different meaning. Software that links against both
4280** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
4281** SQLITE_TEXT.
4282*/
4283#define SQLITE_INTEGER 1
4284#define SQLITE_FLOAT 2
4285#define SQLITE_BLOB 4
4286#define SQLITE_NULL 5
4287#ifdef SQLITE_TEXT
4288# undef SQLITE_TEXT
4289#else
4290# define SQLITE_TEXT 3
4291#endif
4292#define SQLITE3_TEXT 3
4293
4294/*
4295** CAPI3REF: Result Values From A Query
4296** KEYWORDS: {column access functions}
4297** METHOD: sqlite3_stmt
4298**
4299** <b>Summary:</b>
4300** <blockquote><table border=0 cellpadding=0 cellspacing=0>
4301** <tr><td><b>sqlite3_column_blob</b><td>&rarr;<td>BLOB result
4302** <tr><td><b>sqlite3_column_double</b><td>&rarr;<td>REAL result
4303** <tr><td><b>sqlite3_column_int</b><td>&rarr;<td>32-bit INTEGER result
4304** <tr><td><b>sqlite3_column_int64</b><td>&rarr;<td>64-bit INTEGER result
4305** <tr><td><b>sqlite3_column_text</b><td>&rarr;<td>UTF-8 TEXT result
4306** <tr><td><b>sqlite3_column_text16</b><td>&rarr;<td>UTF-16 TEXT result
4307** <tr><td><b>sqlite3_column_value</b><td>&rarr;<td>The result as an
4308** [sqlite3_value|unprotected sqlite3_value] object.
4309** <tr><td>&nbsp;<td>&nbsp;<td>&nbsp;
4310** <tr><td><b>sqlite3_column_bytes</b><td>&rarr;<td>Size of a BLOB
4311** or a UTF-8 TEXT result in bytes
4312** <tr><td><b>sqlite3_column_bytes16&nbsp;&nbsp;</b>
4313** <td>&rarr;&nbsp;&nbsp;<td>Size of UTF-16
4314** TEXT in bytes
4315** <tr><td><b>sqlite3_column_type</b><td>&rarr;<td>Default
4316** datatype of the result
4317** </table></blockquote>
4318**
4319** <b>Details:</b>
4320**
4321** ^These routines return information about a single column of the current
4322** result row of a query. ^In every case the first argument is a pointer
4323** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
4324** that was returned from [sqlite3_prepare_v2()] or one of its variants)
4325** and the second argument is the index of the column for which information
4326** should be returned. ^The leftmost column of the result set has the index 0.
4327** ^The number of columns in the result can be determined using
4328** [sqlite3_column_count()].
4329**
4330** If the SQL statement does not currently point to a valid row, or if the
4331** column index is out of range, the result is undefined.
4332** These routines may only be called when the most recent call to
4333** [sqlite3_step()] has returned [SQLITE_ROW] and neither
4334** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
4335** If any of these routines are called after [sqlite3_reset()] or
4336** [sqlite3_finalize()] or after [sqlite3_step()] has returned
4337** something other than [SQLITE_ROW], the results are undefined.
4338** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
4339** are called from a different thread while any of these routines
4340** are pending, then the results are undefined.
4341**
4342** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16)
4343** each return the value of a result column in a specific data format. If
4344** the result column is not initially in the requested format (for example,
4345** if the query returns an integer but the sqlite3_column_text() interface
4346** is used to extract the value) then an automatic type conversion is performed.
4347**
4348** ^The sqlite3_column_type() routine returns the
4349** [SQLITE_INTEGER | datatype code] for the initial data type
4350** of the result column. ^The returned value is one of [SQLITE_INTEGER],
4351** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].
4352** The return value of sqlite3_column_type() can be used to decide which
4353** of the first six interface should be used to extract the column value.
4354** The value returned by sqlite3_column_type() is only meaningful if no
4355** automatic type conversions have occurred for the value in question.
4356** After a type conversion, the result of calling sqlite3_column_type()
4357** is undefined, though harmless. Future
4358** versions of SQLite may change the behavior of sqlite3_column_type()
4359** following a type conversion.
4360**
4361** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes()
4362** or sqlite3_column_bytes16() interfaces can be used to determine the size
4363** of that BLOB or string.
4364**
4365** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
4366** routine returns the number of bytes in that BLOB or string.
4367** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
4368** the string to UTF-8 and then returns the number of bytes.
4369** ^If the result is a numeric value then sqlite3_column_bytes() uses
4370** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
4371** the number of bytes in that string.
4372** ^If the result is NULL, then sqlite3_column_bytes() returns zero.
4373**
4374** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()
4375** routine returns the number of bytes in that BLOB or string.
4376** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts
4377** the string to UTF-16 and then returns the number of bytes.
4378** ^If the result is a numeric value then sqlite3_column_bytes16() uses
4379** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns
4380** the number of bytes in that string.
4381** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.
4382**
4383** ^The values returned by [sqlite3_column_bytes()] and
4384** [sqlite3_column_bytes16()] do not include the zero terminators at the end
4385** of the string. ^For clarity: the values returned by
4386** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of
4387** bytes in the string, not the number of characters.
4388**
4389** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
4390** even empty strings, are always zero-terminated. ^The return
4391** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
4392**
4393** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an
4394** [unprotected sqlite3_value] object. In a multithreaded environment,
4395** an unprotected sqlite3_value object may only be used safely with
4396** [sqlite3_bind_value()] and [sqlite3_result_value()].
4397** If the [unprotected sqlite3_value] object returned by
4398** [sqlite3_column_value()] is used in any other way, including calls
4399** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
4400** or [sqlite3_value_bytes()], the behavior is not threadsafe.
4401** Hence, the sqlite3_column_value() interface
4402** is normally only useful within the implementation of
4403** [application-defined SQL functions] or [virtual tables], not within
4404** top-level application code.
4405**
4406** The these routines may attempt to convert the datatype of the result.
4407** ^For example, if the internal representation is FLOAT and a text result
4408** is requested, [sqlite3_snprintf()] is used internally to perform the
4409** conversion automatically. ^(The following table details the conversions
4410** that are applied:
4411**
4412** <blockquote>
4413** <table border="1">
4414** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion
4415**
4416** <tr><td> NULL <td> INTEGER <td> Result is 0
4417** <tr><td> NULL <td> FLOAT <td> Result is 0.0
4418** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer
4419** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer
4420** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float
4421** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer
4422** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT
4423** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER
4424** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float
4425** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB
4426** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER
4427** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL
4428** <tr><td> TEXT <td> BLOB <td> No change
4429** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER
4430** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL
4431** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed
4432** </table>
4433** </blockquote>)^
4434**
4435** Note that when type conversions occur, pointers returned by prior
4436** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
4437** sqlite3_column_text16() may be invalidated.
4438** Type conversions and pointer invalidations might occur
4439** in the following cases:
4440**
4441** <ul>
4442** <li> The initial content is a BLOB and sqlite3_column_text() or
4443** sqlite3_column_text16() is called. A zero-terminator might
4444** need to be added to the string.</li>
4445** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
4446** sqlite3_column_text16() is called. The content must be converted
4447** to UTF-16.</li>
4448** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
4449** sqlite3_column_text() is called. The content must be converted
4450** to UTF-8.</li>
4451** </ul>
4452**
4453** ^Conversions between UTF-16be and UTF-16le are always done in place and do
4454** not invalidate a prior pointer, though of course the content of the buffer
4455** that the prior pointer references will have been modified. Other kinds
4456** of conversion are done in place when it is possible, but sometimes they
4457** are not possible and in those cases prior pointers are invalidated.
4458**
4459** The safest policy is to invoke these routines
4460** in one of the following ways:
4461**
4462** <ul>
4463** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
4464** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
4465** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
4466** </ul>
4467**
4468** In other words, you should call sqlite3_column_text(),
4469** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
4470** into the desired format, then invoke sqlite3_column_bytes() or
4471** sqlite3_column_bytes16() to find the size of the result. Do not mix calls
4472** to sqlite3_column_text() or sqlite3_column_blob() with calls to
4473** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
4474** with calls to sqlite3_column_bytes().
4475**
4476** ^The pointers returned are valid until a type conversion occurs as
4477** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
4478** [sqlite3_finalize()] is called. ^The memory space used to hold strings
4479** and BLOBs is freed automatically. Do not pass the pointers returned
4480** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
4481** [sqlite3_free()].
4482**
4483** ^(If a memory allocation error occurs during the evaluation of any
4484** of these routines, a default value is returned. The default value
4485** is either the integer 0, the floating point number 0.0, or a NULL
4486** pointer. Subsequent calls to [sqlite3_errcode()] will return
4487** [SQLITE_NOMEM].)^
4488*/
4489SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
4490SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol);
4491SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol);
4492SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
4493SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
4494SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
4495SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
4496SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
4497SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
4498SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol);
4499
4500/*
4501** CAPI3REF: Destroy A Prepared Statement Object
4502** DESTRUCTOR: sqlite3_stmt
4503**
4504** ^The sqlite3_finalize() function is called to delete a [prepared statement].
4505** ^If the most recent evaluation of the statement encountered no errors
4506** or if the statement is never been evaluated, then sqlite3_finalize() returns
4507** SQLITE_OK. ^If the most recent evaluation of statement S failed, then
4508** sqlite3_finalize(S) returns the appropriate [error code] or
4509** [extended error code].
4510**
4511** ^The sqlite3_finalize(S) routine can be called at any point during
4512** the life cycle of [prepared statement] S:
4513** before statement S is ever evaluated, after
4514** one or more calls to [sqlite3_reset()], or after any call
4515** to [sqlite3_step()] regardless of whether or not the statement has
4516** completed execution.
4517**
4518** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.
4519**
4520** The application must finalize every [prepared statement] in order to avoid
4521** resource leaks. It is a grievous error for the application to try to use
4522** a prepared statement after it has been finalized. Any use of a prepared
4523** statement after it has been finalized can result in undefined and
4524** undesirable behavior such as segfaults and heap corruption.
4525*/
4526SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt);
4527
4528/*
4529** CAPI3REF: Reset A Prepared Statement Object
4530** METHOD: sqlite3_stmt
4531**
4532** The sqlite3_reset() function is called to reset a [prepared statement]
4533** object back to its initial state, ready to be re-executed.
4534** ^Any SQL statement variables that had values bound to them using
4535** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
4536** Use [sqlite3_clear_bindings()] to reset the bindings.
4537**
4538** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
4539** back to the beginning of its program.
4540**
4541** ^If the most recent call to [sqlite3_step(S)] for the
4542** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE],
4543** or if [sqlite3_step(S)] has never before been called on S,
4544** then [sqlite3_reset(S)] returns [SQLITE_OK].
4545**
4546** ^If the most recent call to [sqlite3_step(S)] for the
4547** [prepared statement] S indicated an error, then
4548** [sqlite3_reset(S)] returns an appropriate [error code].
4549**
4550** ^The [sqlite3_reset(S)] interface does not change the values
4551** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
4552*/
4553SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);
4554
4555/*
4556** CAPI3REF: Create Or Redefine SQL Functions
4557** KEYWORDS: {function creation routines}
4558** KEYWORDS: {application-defined SQL function}
4559** KEYWORDS: {application-defined SQL functions}
4560** METHOD: sqlite3
4561**
4562** ^These functions (collectively known as "function creation routines")
4563** are used to add SQL functions or aggregates or to redefine the behavior
4564** of existing SQL functions or aggregates. The only differences between
4565** these routines are the text encoding expected for
4566** the second parameter (the name of the function being created)
4567** and the presence or absence of a destructor callback for
4568** the application data pointer.
4569**
4570** ^The first parameter is the [database connection] to which the SQL
4571** function is to be added. ^If an application uses more than one database
4572** connection then application-defined SQL functions must be added
4573** to each database connection separately.
4574**
4575** ^The second parameter is the name of the SQL function to be created or
4576** redefined. ^The length of the name is limited to 255 bytes in a UTF-8
4577** representation, exclusive of the zero-terminator. ^Note that the name
4578** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.
4579** ^Any attempt to create a function with a longer name
4580** will result in [SQLITE_MISUSE] being returned.
4581**
4582** ^The third parameter (nArg)
4583** is the number of arguments that the SQL function or
4584** aggregate takes. ^If this parameter is -1, then the SQL function or
4585** aggregate may take any number of arguments between 0 and the limit
4586** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third
4587** parameter is less than -1 or greater than 127 then the behavior is
4588** undefined.
4589**
4590** ^The fourth parameter, eTextRep, specifies what
4591** [SQLITE_UTF8 | text encoding] this SQL function prefers for
4592** its parameters. The application should set this parameter to
4593** [SQLITE_UTF16LE] if the function implementation invokes
4594** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the
4595** implementation invokes [sqlite3_value_text16be()] on an input, or
4596** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8]
4597** otherwise. ^The same SQL function may be registered multiple times using
4598** different preferred text encodings, with different implementations for
4599** each encoding.
4600** ^When multiple implementations of the same function are available, SQLite
4601** will pick the one that involves the least amount of data conversion.
4602**
4603** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC]
4604** to signal that the function will always return the same result given
4605** the same inputs within a single SQL statement. Most SQL functions are
4606** deterministic. The built-in [random()] SQL function is an example of a
4607** function that is not deterministic. The SQLite query planner is able to
4608** perform additional optimizations on deterministic functions, so use
4609** of the [SQLITE_DETERMINISTIC] flag is recommended where possible.
4610**
4611** ^(The fifth parameter is an arbitrary pointer. The implementation of the
4612** function can gain access to this pointer using [sqlite3_user_data()].)^
4613**
4614** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are
4615** pointers to C-language functions that implement the SQL function or
4616** aggregate. ^A scalar SQL function requires an implementation of the xFunc
4617** callback only; NULL pointers must be passed as the xStep and xFinal
4618** parameters. ^An aggregate SQL function requires an implementation of xStep
4619** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
4620** SQL function or aggregate, pass NULL pointers for all three function
4621** callbacks.
4622**
4623** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL,
4624** then it is destructor for the application data pointer.
4625** The destructor is invoked when the function is deleted, either by being
4626** overloaded or when the database connection closes.)^
4627** ^The destructor is also invoked if the call to
4628** sqlite3_create_function_v2() fails.
4629** ^When the destructor callback of the tenth parameter is invoked, it
4630** is passed a single argument which is a copy of the application data
4631** pointer which was the fifth parameter to sqlite3_create_function_v2().
4632**
4633** ^It is permitted to register multiple implementations of the same
4634** functions with the same name but with either differing numbers of
4635** arguments or differing preferred text encodings. ^SQLite will use
4636** the implementation that most closely matches the way in which the
4637** SQL function is used. ^A function implementation with a non-negative
4638** nArg parameter is a better match than a function implementation with
4639** a negative nArg. ^A function where the preferred text encoding
4640** matches the database encoding is a better
4641** match than a function where the encoding is different.
4642** ^A function where the encoding difference is between UTF16le and UTF16be
4643** is a closer match than a function where the encoding difference is
4644** between UTF8 and UTF16.
4645**
4646** ^Built-in functions may be overloaded by new application-defined functions.
4647**
4648** ^An application-defined function is permitted to call other
4649** SQLite interfaces. However, such calls must not
4650** close the database connection nor finalize or reset the prepared
4651** statement in which the function is running.
4652*/
4653SQLITE_API int sqlite3_create_function(
4654 sqlite3 *db,
4655 const char *zFunctionName,
4656 int nArg,
4657 int eTextRep,
4658 void *pApp,
4659 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
4660 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4661 void (*xFinal)(sqlite3_context*)
4662);
4663SQLITE_API int sqlite3_create_function16(
4664 sqlite3 *db,
4665 const void *zFunctionName,
4666 int nArg,
4667 int eTextRep,
4668 void *pApp,
4669 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
4670 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4671 void (*xFinal)(sqlite3_context*)
4672);
4673SQLITE_API int sqlite3_create_function_v2(
4674 sqlite3 *db,
4675 const char *zFunctionName,
4676 int nArg,
4677 int eTextRep,
4678 void *pApp,
4679 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
4680 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4681 void (*xFinal)(sqlite3_context*),
4682 void(*xDestroy)(void*)
4683);
4684
4685/*
4686** CAPI3REF: Text Encodings
4687**
4688** These constant define integer codes that represent the various
4689** text encodings supported by SQLite.
4690*/
4691#define SQLITE_UTF8 1 /* IMP: R-37514-35566 */
4692#define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */
4693#define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */
4694#define SQLITE_UTF16 4 /* Use native byte order */
4695#define SQLITE_ANY 5 /* Deprecated */
4696#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */
4697
4698/*
4699** CAPI3REF: Function Flags
4700**
4701** These constants may be ORed together with the
4702** [SQLITE_UTF8 | preferred text encoding] as the fourth argument
4703** to [sqlite3_create_function()], [sqlite3_create_function16()], or
4704** [sqlite3_create_function_v2()].
4705*/
4706#define SQLITE_DETERMINISTIC 0x800
4707
4708/*
4709** CAPI3REF: Deprecated Functions
4710** DEPRECATED
4711**
4712** These functions are [deprecated]. In order to maintain
4713** backwards compatibility with older code, these functions continue
4714** to be supported. However, new applications should avoid
4715** the use of these functions. To encourage programmers to avoid
4716** these functions, we will not explain what they do.
4717*/
4718#ifndef SQLITE_OMIT_DEPRECATED
4719SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*);
4720SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);
4721SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
4722SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void);
4723SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);
4724SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),
4725 void*,sqlite3_int64);
4726#endif
4727
4728/*
4729** CAPI3REF: Obtaining SQL Values
4730** METHOD: sqlite3_value
4731**
4732** <b>Summary:</b>
4733** <blockquote><table border=0 cellpadding=0 cellspacing=0>
4734** <tr><td><b>sqlite3_value_blob</b><td>&rarr;<td>BLOB value
4735** <tr><td><b>sqlite3_value_double</b><td>&rarr;<td>REAL value
4736** <tr><td><b>sqlite3_value_int</b><td>&rarr;<td>32-bit INTEGER value
4737** <tr><td><b>sqlite3_value_int64</b><td>&rarr;<td>64-bit INTEGER value
4738** <tr><td><b>sqlite3_value_pointer</b><td>&rarr;<td>Pointer value
4739** <tr><td><b>sqlite3_value_text</b><td>&rarr;<td>UTF-8 TEXT value
4740** <tr><td><b>sqlite3_value_text16</b><td>&rarr;<td>UTF-16 TEXT value in
4741** the native byteorder
4742** <tr><td><b>sqlite3_value_text16be</b><td>&rarr;<td>UTF-16be TEXT value
4743** <tr><td><b>sqlite3_value_text16le</b><td>&rarr;<td>UTF-16le TEXT value
4744** <tr><td>&nbsp;<td>&nbsp;<td>&nbsp;
4745** <tr><td><b>sqlite3_value_bytes</b><td>&rarr;<td>Size of a BLOB
4746** or a UTF-8 TEXT in bytes
4747** <tr><td><b>sqlite3_value_bytes16&nbsp;&nbsp;</b>
4748** <td>&rarr;&nbsp;&nbsp;<td>Size of UTF-16
4749** TEXT in bytes
4750** <tr><td><b>sqlite3_value_type</b><td>&rarr;<td>Default
4751** datatype of the value
4752** <tr><td><b>sqlite3_value_numeric_type&nbsp;&nbsp;</b>
4753** <td>&rarr;&nbsp;&nbsp;<td>Best numeric datatype of the value
4754** <tr><td><b>sqlite3_value_nochange&nbsp;&nbsp;</b>
4755** <td>&rarr;&nbsp;&nbsp;<td>True if the column is unchanged in an UPDATE
4756** against a virtual table.
4757** </table></blockquote>
4758**
4759** <b>Details:</b>
4760**
4761** These routines extract type, size, and content information from
4762** [protected sqlite3_value] objects. Protected sqlite3_value objects
4763** are used to pass parameter information into implementation of
4764** [application-defined SQL functions] and [virtual tables].
4765**
4766** These routines work only with [protected sqlite3_value] objects.
4767** Any attempt to use these routines on an [unprotected sqlite3_value]
4768** is not threadsafe.
4769**
4770** ^These routines work just like the corresponding [column access functions]
4771** except that these routines take a single [protected sqlite3_value] object
4772** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
4773**
4774** ^The sqlite3_value_text16() interface extracts a UTF-16 string
4775** in the native byte-order of the host machine. ^The
4776** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
4777** extract UTF-16 strings as big-endian and little-endian respectively.
4778**
4779** ^If [sqlite3_value] object V was initialized
4780** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)]
4781** and if X and Y are strings that compare equal according to strcmp(X,Y),
4782** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise,
4783** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer()
4784** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
4785**
4786** ^(The sqlite3_value_type(V) interface returns the
4787** [SQLITE_INTEGER | datatype code] for the initial datatype of the
4788** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER],
4789** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^
4790** Other interfaces might change the datatype for an sqlite3_value object.
4791** For example, if the datatype is initially SQLITE_INTEGER and
4792** sqlite3_value_text(V) is called to extract a text value for that
4793** integer, then subsequent calls to sqlite3_value_type(V) might return
4794** SQLITE_TEXT. Whether or not a persistent internal datatype conversion
4795** occurs is undefined and may change from one release of SQLite to the next.
4796**
4797** ^(The sqlite3_value_numeric_type() interface attempts to apply
4798** numeric affinity to the value. This means that an attempt is
4799** made to convert the value to an integer or floating point. If
4800** such a conversion is possible without loss of information (in other
4801** words, if the value is a string that looks like a number)
4802** then the conversion is performed. Otherwise no conversion occurs.
4803** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
4804**
4805** ^Within the [xUpdate] method of a [virtual table], the
4806** sqlite3_value_nochange(X) interface returns true if and only if
4807** the column corresponding to X is unchanged by the UPDATE operation
4808** that the xUpdate method call was invoked to implement and if
4809** and the prior [xColumn] method call that was invoked to extracted
4810** the value for that column returned without setting a result (probably
4811** because it queried [sqlite3_vtab_nochange()] and found that the column
4812** was unchanging). ^Within an [xUpdate] method, any value for which
4813** sqlite3_value_nochange(X) is true will in all other respects appear
4814** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other
4815** than within an [xUpdate] method call for an UPDATE statement, then
4816** the return value is arbitrary and meaningless.
4817**
4818** Please pay particular attention to the fact that the pointer returned
4819** from [sqlite3_value_blob()], [sqlite3_value_text()], or
4820** [sqlite3_value_text16()] can be invalidated by a subsequent call to
4821** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
4822** or [sqlite3_value_text16()].
4823**
4824** These routines must be called from the same thread as
4825** the SQL function that supplied the [sqlite3_value*] parameters.
4826*/
4827SQLITE_API const void *sqlite3_value_blob(sqlite3_value*);
4828SQLITE_API double sqlite3_value_double(sqlite3_value*);
4829SQLITE_API int sqlite3_value_int(sqlite3_value*);
4830SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
4831SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*);
4832SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*);
4833SQLITE_API const void *sqlite3_value_text16(sqlite3_value*);
4834SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*);
4835SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*);
4836SQLITE_API int sqlite3_value_bytes(sqlite3_value*);
4837SQLITE_API int sqlite3_value_bytes16(sqlite3_value*);
4838SQLITE_API int sqlite3_value_type(sqlite3_value*);
4839SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*);
4840SQLITE_API int sqlite3_value_nochange(sqlite3_value*);
4841
4842/*
4843** CAPI3REF: Finding The Subtype Of SQL Values
4844** METHOD: sqlite3_value
4845**
4846** The sqlite3_value_subtype(V) function returns the subtype for
4847** an [application-defined SQL function] argument V. The subtype
4848** information can be used to pass a limited amount of context from
4849** one SQL function to another. Use the [sqlite3_result_subtype()]
4850** routine to set the subtype for the return value of an SQL function.
4851*/
4852SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*);
4853
4854/*
4855** CAPI3REF: Copy And Free SQL Values
4856** METHOD: sqlite3_value
4857**
4858** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value]
4859** object D and returns a pointer to that copy. ^The [sqlite3_value] returned
4860** is a [protected sqlite3_value] object even if the input is not.
4861** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a
4862** memory allocation fails.
4863**
4864** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object
4865** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer
4866** then sqlite3_value_free(V) is a harmless no-op.
4867*/
4868SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*);
4869SQLITE_API void sqlite3_value_free(sqlite3_value*);
4870
4871/*
4872** CAPI3REF: Obtain Aggregate Function Context
4873** METHOD: sqlite3_context
4874**
4875** Implementations of aggregate SQL functions use this
4876** routine to allocate memory for storing their state.
4877**
4878** ^The first time the sqlite3_aggregate_context(C,N) routine is called
4879** for a particular aggregate function, SQLite
4880** allocates N of memory, zeroes out that memory, and returns a pointer
4881** to the new memory. ^On second and subsequent calls to
4882** sqlite3_aggregate_context() for the same aggregate function instance,
4883** the same buffer is returned. Sqlite3_aggregate_context() is normally
4884** called once for each invocation of the xStep callback and then one
4885** last time when the xFinal callback is invoked. ^(When no rows match
4886** an aggregate query, the xStep() callback of the aggregate function
4887** implementation is never called and xFinal() is called exactly once.
4888** In those cases, sqlite3_aggregate_context() might be called for the
4889** first time from within xFinal().)^
4890**
4891** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer
4892** when first called if N is less than or equal to zero or if a memory
4893** allocate error occurs.
4894**
4895** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
4896** determined by the N parameter on first successful call. Changing the
4897** value of N in subsequent call to sqlite3_aggregate_context() within
4898** the same aggregate function instance will not resize the memory
4899** allocation.)^ Within the xFinal callback, it is customary to set
4900** N=0 in calls to sqlite3_aggregate_context(C,N) so that no
4901** pointless memory allocations occur.
4902**
4903** ^SQLite automatically frees the memory allocated by
4904** sqlite3_aggregate_context() when the aggregate query concludes.
4905**
4906** The first parameter must be a copy of the
4907** [sqlite3_context | SQL function context] that is the first parameter
4908** to the xStep or xFinal callback routine that implements the aggregate
4909** function.
4910**
4911** This routine must be called from the same thread in which
4912** the aggregate SQL function is running.
4913*/
4914SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
4915
4916/*
4917** CAPI3REF: User Data For Functions
4918** METHOD: sqlite3_context
4919**
4920** ^The sqlite3_user_data() interface returns a copy of
4921** the pointer that was the pUserData parameter (the 5th parameter)
4922** of the [sqlite3_create_function()]
4923** and [sqlite3_create_function16()] routines that originally
4924** registered the application defined function.
4925**
4926** This routine must be called from the same thread in which
4927** the application-defined function is running.
4928*/
4929SQLITE_API void *sqlite3_user_data(sqlite3_context*);
4930
4931/*
4932** CAPI3REF: Database Connection For Functions
4933** METHOD: sqlite3_context
4934**
4935** ^The sqlite3_context_db_handle() interface returns a copy of
4936** the pointer to the [database connection] (the 1st parameter)
4937** of the [sqlite3_create_function()]
4938** and [sqlite3_create_function16()] routines that originally
4939** registered the application defined function.
4940*/
4941SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*);
4942
4943/*
4944** CAPI3REF: Function Auxiliary Data
4945** METHOD: sqlite3_context
4946**
4947** These functions may be used by (non-aggregate) SQL functions to
4948** associate metadata with argument values. If the same value is passed to
4949** multiple invocations of the same SQL function during query execution, under
4950** some circumstances the associated metadata may be preserved. An example
4951** of where this might be useful is in a regular-expression matching
4952** function. The compiled version of the regular expression can be stored as
4953** metadata associated with the pattern string.
4954** Then as long as the pattern string remains the same,
4955** the compiled regular expression can be reused on multiple
4956** invocations of the same function.
4957**
4958** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata
4959** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument
4960** value to the application-defined function. ^N is zero for the left-most
4961** function argument. ^If there is no metadata
4962** associated with the function argument, the sqlite3_get_auxdata(C,N) interface
4963** returns a NULL pointer.
4964**
4965** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th
4966** argument of the application-defined function. ^Subsequent
4967** calls to sqlite3_get_auxdata(C,N) return P from the most recent
4968** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or
4969** NULL if the metadata has been discarded.
4970** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL,
4971** SQLite will invoke the destructor function X with parameter P exactly
4972** once, when the metadata is discarded.
4973** SQLite is free to discard the metadata at any time, including: <ul>
4974** <li> ^(when the corresponding function parameter changes)^, or
4975** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the
4976** SQL statement)^, or
4977** <li> ^(when sqlite3_set_auxdata() is invoked again on the same
4978** parameter)^, or
4979** <li> ^(during the original sqlite3_set_auxdata() call when a memory
4980** allocation error occurs.)^ </ul>
4981**
4982** Note the last bullet in particular. The destructor X in
4983** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the
4984** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata()
4985** should be called near the end of the function implementation and the
4986** function implementation should not make any use of P after
4987** sqlite3_set_auxdata() has been called.
4988**
4989** ^(In practice, metadata is preserved between function calls for
4990** function parameters that are compile-time constants, including literal
4991** values and [parameters] and expressions composed from the same.)^
4992**
4993** The value of the N parameter to these interfaces should be non-negative.
4994** Future enhancements may make use of negative N values to define new
4995** kinds of function caching behavior.
4996**
4997** These routines must be called from the same thread in which
4998** the SQL function is running.
4999*/
5000SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N);
5001SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
5002
5003
5004/*
5005** CAPI3REF: Constants Defining Special Destructor Behavior
5006**
5007** These are special values for the destructor that is passed in as the
5008** final argument to routines like [sqlite3_result_blob()]. ^If the destructor
5009** argument is SQLITE_STATIC, it means that the content pointer is constant
5010** and will never change. It does not need to be destroyed. ^The
5011** SQLITE_TRANSIENT value means that the content will likely change in
5012** the near future and that SQLite should make its own private copy of
5013** the content before returning.
5014**
5015** The typedef is necessary to work around problems in certain
5016** C++ compilers.
5017*/
5018typedef void (*sqlite3_destructor_type)(void*);
5019#define SQLITE_STATIC ((sqlite3_destructor_type)0)
5020#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1)
5021
5022/*
5023** CAPI3REF: Setting The Result Of An SQL Function
5024** METHOD: sqlite3_context
5025**
5026** These routines are used by the xFunc or xFinal callbacks that
5027** implement SQL functions and aggregates. See
5028** [sqlite3_create_function()] and [sqlite3_create_function16()]
5029** for additional information.
5030**
5031** These functions work very much like the [parameter binding] family of
5032** functions used to bind values to host parameters in prepared statements.
5033** Refer to the [SQL parameter] documentation for additional information.
5034**
5035** ^The sqlite3_result_blob() interface sets the result from
5036** an application-defined function to be the BLOB whose content is pointed
5037** to by the second parameter and which is N bytes long where N is the
5038** third parameter.
5039**
5040** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N)
5041** interfaces set the result of the application-defined function to be
5042** a BLOB containing all zero bytes and N bytes in size.
5043**
5044** ^The sqlite3_result_double() interface sets the result from
5045** an application-defined function to be a floating point value specified
5046** by its 2nd argument.
5047**
5048** ^The sqlite3_result_error() and sqlite3_result_error16() functions
5049** cause the implemented SQL function to throw an exception.
5050** ^SQLite uses the string pointed to by the
5051** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
5052** as the text of an error message. ^SQLite interprets the error
5053** message string from sqlite3_result_error() as UTF-8. ^SQLite
5054** interprets the string from sqlite3_result_error16() as UTF-16 in native
5055** byte order. ^If the third parameter to sqlite3_result_error()
5056** or sqlite3_result_error16() is negative then SQLite takes as the error
5057** message all text up through the first zero character.
5058** ^If the third parameter to sqlite3_result_error() or
5059** sqlite3_result_error16() is non-negative then SQLite takes that many
5060** bytes (not characters) from the 2nd parameter as the error message.
5061** ^The sqlite3_result_error() and sqlite3_result_error16()
5062** routines make a private copy of the error message text before
5063** they return. Hence, the calling function can deallocate or
5064** modify the text after they return without harm.
5065** ^The sqlite3_result_error_code() function changes the error code
5066** returned by SQLite as a result of an error in a function. ^By default,
5067** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error()
5068** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
5069**
5070** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an
5071** error indicating that a string or BLOB is too long to represent.
5072**
5073** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an
5074** error indicating that a memory allocation failed.
5075**
5076** ^The sqlite3_result_int() interface sets the return value
5077** of the application-defined function to be the 32-bit signed integer
5078** value given in the 2nd argument.
5079** ^The sqlite3_result_int64() interface sets the return value
5080** of the application-defined function to be the 64-bit signed integer
5081** value given in the 2nd argument.
5082**
5083** ^The sqlite3_result_null() interface sets the return value
5084** of the application-defined function to be NULL.
5085**
5086** ^The sqlite3_result_text(), sqlite3_result_text16(),
5087** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
5088** set the return value of the application-defined function to be
5089** a text string which is represented as UTF-8, UTF-16 native byte order,
5090** UTF-16 little endian, or UTF-16 big endian, respectively.
5091** ^The sqlite3_result_text64() interface sets the return value of an
5092** application-defined function to be a text string in an encoding
5093** specified by the fifth (and last) parameter, which must be one
5094** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE].
5095** ^SQLite takes the text result from the application from
5096** the 2nd parameter of the sqlite3_result_text* interfaces.
5097** ^If the 3rd parameter to the sqlite3_result_text* interfaces
5098** is negative, then SQLite takes result text from the 2nd parameter
5099** through the first zero character.
5100** ^If the 3rd parameter to the sqlite3_result_text* interfaces
5101** is non-negative, then as many bytes (not characters) of the text
5102** pointed to by the 2nd parameter are taken as the application-defined
5103** function result. If the 3rd parameter is non-negative, then it
5104** must be the byte offset into the string where the NUL terminator would
5105** appear if the string where NUL terminated. If any NUL characters occur
5106** in the string at a byte offset that is less than the value of the 3rd
5107** parameter, then the resulting string will contain embedded NULs and the
5108** result of expressions operating on strings with embedded NULs is undefined.
5109** ^If the 4th parameter to the sqlite3_result_text* interfaces
5110** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
5111** function as the destructor on the text or BLOB result when it has
5112** finished using that result.
5113** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
5114** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
5115** assumes that the text or BLOB result is in constant space and does not
5116** copy the content of the parameter nor call a destructor on the content
5117** when it has finished using that result.
5118** ^If the 4th parameter to the sqlite3_result_text* interfaces
5119** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
5120** then SQLite makes a copy of the result into space obtained
5121** from [sqlite3_malloc()] before it returns.
5122**
5123** ^The sqlite3_result_value() interface sets the result of
5124** the application-defined function to be a copy of the
5125** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The
5126** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
5127** so that the [sqlite3_value] specified in the parameter may change or
5128** be deallocated after sqlite3_result_value() returns without harm.
5129** ^A [protected sqlite3_value] object may always be used where an
5130** [unprotected sqlite3_value] object is required, so either
5131** kind of [sqlite3_value] object can be used with this interface.
5132**
5133** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an
5134** SQL NULL value, just like [sqlite3_result_null(C)], except that it
5135** also associates the host-language pointer P or type T with that
5136** NULL value such that the pointer can be retrieved within an
5137** [application-defined SQL function] using [sqlite3_value_pointer()].
5138** ^If the D parameter is not NULL, then it is a pointer to a destructor
5139** for the P parameter. ^SQLite invokes D with P as its only argument
5140** when SQLite is finished with P. The T parameter should be a static
5141** string and preferably a string literal. The sqlite3_result_pointer()
5142** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
5143**
5144** If these routines are called from within the different thread
5145** than the one containing the application-defined function that received
5146** the [sqlite3_context] pointer, the results are undefined.
5147*/
5148SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
5149SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*,
5150 sqlite3_uint64,void(*)(void*));
5151SQLITE_API void sqlite3_result_double(sqlite3_context*, double);
5152SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int);
5153SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int);
5154SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*);
5155SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*);
5156SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int);
5157SQLITE_API void sqlite3_result_int(sqlite3_context*, int);
5158SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
5159SQLITE_API void sqlite3_result_null(sqlite3_context*);
5160SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
5161SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64,
5162 void(*)(void*), unsigned char encoding);
5163SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
5164SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
5165SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
5166SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
5167SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*));
5168SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n);
5169SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n);
5170
5171
5172/*
5173** CAPI3REF: Setting The Subtype Of An SQL Function
5174** METHOD: sqlite3_context
5175**
5176** The sqlite3_result_subtype(C,T) function causes the subtype of
5177** the result from the [application-defined SQL function] with
5178** [sqlite3_context] C to be the value T. Only the lower 8 bits
5179** of the subtype T are preserved in current versions of SQLite;
5180** higher order bits are discarded.
5181** The number of subtype bytes preserved by SQLite might increase
5182** in future releases of SQLite.
5183*/
5184SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int);
5185
5186/*
5187** CAPI3REF: Define New Collating Sequences
5188** METHOD: sqlite3
5189**
5190** ^These functions add, remove, or modify a [collation] associated
5191** with the [database connection] specified as the first argument.
5192**
5193** ^The name of the collation is a UTF-8 string
5194** for sqlite3_create_collation() and sqlite3_create_collation_v2()
5195** and a UTF-16 string in native byte order for sqlite3_create_collation16().
5196** ^Collation names that compare equal according to [sqlite3_strnicmp()] are
5197** considered to be the same name.
5198**
5199** ^(The third argument (eTextRep) must be one of the constants:
5200** <ul>
5201** <li> [SQLITE_UTF8],
5202** <li> [SQLITE_UTF16LE],
5203** <li> [SQLITE_UTF16BE],
5204** <li> [SQLITE_UTF16], or
5205** <li> [SQLITE_UTF16_ALIGNED].
5206** </ul>)^
5207** ^The eTextRep argument determines the encoding of strings passed
5208** to the collating function callback, xCallback.
5209** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
5210** force strings to be UTF16 with native byte order.
5211** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
5212** on an even byte address.
5213**
5214** ^The fourth argument, pArg, is an application data pointer that is passed
5215** through as the first argument to the collating function callback.
5216**
5217** ^The fifth argument, xCallback, is a pointer to the collating function.
5218** ^Multiple collating functions can be registered using the same name but
5219** with different eTextRep parameters and SQLite will use whichever
5220** function requires the least amount of data transformation.
5221** ^If the xCallback argument is NULL then the collating function is
5222** deleted. ^When all collating functions having the same name are deleted,
5223** that collation is no longer usable.
5224**
5225** ^The collating function callback is invoked with a copy of the pArg
5226** application data pointer and with two strings in the encoding specified
5227** by the eTextRep argument. The collating function must return an
5228** integer that is negative, zero, or positive
5229** if the first string is less than, equal to, or greater than the second,
5230** respectively. A collating function must always return the same answer
5231** given the same inputs. If two or more collating functions are registered
5232** to the same collation name (using different eTextRep values) then all
5233** must give an equivalent answer when invoked with equivalent strings.
5234** The collating function must obey the following properties for all
5235** strings A, B, and C:
5236**
5237** <ol>
5238** <li> If A==B then B==A.
5239** <li> If A==B and B==C then A==C.
5240** <li> If A&lt;B THEN B&gt;A.
5241** <li> If A&lt;B and B&lt;C then A&lt;C.
5242** </ol>
5243**
5244** If a collating function fails any of the above constraints and that
5245** collating function is registered and used, then the behavior of SQLite
5246** is undefined.
5247**
5248** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
5249** with the addition that the xDestroy callback is invoked on pArg when
5250** the collating function is deleted.
5251** ^Collating functions are deleted when they are overridden by later
5252** calls to the collation creation functions or when the
5253** [database connection] is closed using [sqlite3_close()].
5254**
5255** ^The xDestroy callback is <u>not</u> called if the
5256** sqlite3_create_collation_v2() function fails. Applications that invoke
5257** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should
5258** check the return code and dispose of the application data pointer
5259** themselves rather than expecting SQLite to deal with it for them.
5260** This is different from every other SQLite interface. The inconsistency
5261** is unfortunate but cannot be changed without breaking backwards
5262** compatibility.
5263**
5264** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
5265*/
5266SQLITE_API int sqlite3_create_collation(
5267 sqlite3*,
5268 const char *zName,
5269 int eTextRep,
5270 void *pArg,
5271 int(*xCompare)(void*,int,const void*,int,const void*)
5272);
5273SQLITE_API int sqlite3_create_collation_v2(
5274 sqlite3*,
5275 const char *zName,
5276 int eTextRep,
5277 void *pArg,
5278 int(*xCompare)(void*,int,const void*,int,const void*),
5279 void(*xDestroy)(void*)
5280);
5281SQLITE_API int sqlite3_create_collation16(
5282 sqlite3*,
5283 const void *zName,
5284 int eTextRep,
5285 void *pArg,
5286 int(*xCompare)(void*,int,const void*,int,const void*)
5287);
5288
5289/*
5290** CAPI3REF: Collation Needed Callbacks
5291** METHOD: sqlite3
5292**
5293** ^To avoid having to register all collation sequences before a database
5294** can be used, a single callback function may be registered with the
5295** [database connection] to be invoked whenever an undefined collation
5296** sequence is required.
5297**
5298** ^If the function is registered using the sqlite3_collation_needed() API,
5299** then it is passed the names of undefined collation sequences as strings
5300** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
5301** the names are passed as UTF-16 in machine native byte order.
5302** ^A call to either function replaces the existing collation-needed callback.
5303**
5304** ^(When the callback is invoked, the first argument passed is a copy
5305** of the second argument to sqlite3_collation_needed() or
5306** sqlite3_collation_needed16(). The second argument is the database
5307** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
5308** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
5309** sequence function required. The fourth parameter is the name of the
5310** required collation sequence.)^
5311**
5312** The callback function should register the desired collation using
5313** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
5314** [sqlite3_create_collation_v2()].
5315*/
5316SQLITE_API int sqlite3_collation_needed(
5317 sqlite3*,
5318 void*,
5319 void(*)(void*,sqlite3*,int eTextRep,const char*)
5320);
5321SQLITE_API int sqlite3_collation_needed16(
5322 sqlite3*,
5323 void*,
5324 void(*)(void*,sqlite3*,int eTextRep,const void*)
5325);
5326
5327#ifdef SQLITE_HAS_CODEC
5328/*
5329** Specify the key for an encrypted database. This routine should be
5330** called right after sqlite3_open().
5331**
5332** The code to implement this API is not available in the public release
5333** of SQLite.
5334*/
5335SQLITE_API int sqlite3_key(
5336 sqlite3 *db, /* Database to be rekeyed */
5337 const void *pKey, int nKey /* The key */
5338);
5339SQLITE_API int sqlite3_key_v2(
5340 sqlite3 *db, /* Database to be rekeyed */
5341 const char *zDbName, /* Name of the database */
5342 const void *pKey, int nKey /* The key */
5343);
5344
5345/*
5346** Change the key on an open database. If the current database is not
5347** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the
5348** database is decrypted.
5349**
5350** The code to implement this API is not available in the public release
5351** of SQLite.
5352*/
5353SQLITE_API int sqlite3_rekey(
5354 sqlite3 *db, /* Database to be rekeyed */
5355 const void *pKey, int nKey /* The new key */
5356);
5357SQLITE_API int sqlite3_rekey_v2(
5358 sqlite3 *db, /* Database to be rekeyed */
5359 const char *zDbName, /* Name of the database */
5360 const void *pKey, int nKey /* The new key */
5361);
5362
5363/*
5364** Specify the activation key for a SEE database. Unless
5365** activated, none of the SEE routines will work.
5366*/
5367SQLITE_API void sqlite3_activate_see(
5368 const char *zPassPhrase /* Activation phrase */
5369);
5370#endif
5371
5372#ifdef SQLITE_ENABLE_CEROD
5373/*
5374** Specify the activation key for a CEROD database. Unless
5375** activated, none of the CEROD routines will work.
5376*/
5377SQLITE_API void sqlite3_activate_cerod(
5378 const char *zPassPhrase /* Activation phrase */
5379);
5380#endif
5381
5382/*
5383** CAPI3REF: Suspend Execution For A Short Time
5384**
5385** The sqlite3_sleep() function causes the current thread to suspend execution
5386** for at least a number of milliseconds specified in its parameter.
5387**
5388** If the operating system does not support sleep requests with
5389** millisecond time resolution, then the time will be rounded up to
5390** the nearest second. The number of milliseconds of sleep actually
5391** requested from the operating system is returned.
5392**
5393** ^SQLite implements this interface by calling the xSleep()
5394** method of the default [sqlite3_vfs] object. If the xSleep() method
5395** of the default VFS is not implemented correctly, or not implemented at
5396** all, then the behavior of sqlite3_sleep() may deviate from the description
5397** in the previous paragraphs.
5398*/
5399SQLITE_API int sqlite3_sleep(int);
5400
5401/*
5402** CAPI3REF: Name Of The Folder Holding Temporary Files
5403**
5404** ^(If this global variable is made to point to a string which is
5405** the name of a folder (a.k.a. directory), then all temporary files
5406** created by SQLite when using a built-in [sqlite3_vfs | VFS]
5407** will be placed in that directory.)^ ^If this variable
5408** is a NULL pointer, then SQLite performs a search for an appropriate
5409** temporary file directory.
5410**
5411** Applications are strongly discouraged from using this global variable.
5412** It is required to set a temporary folder on Windows Runtime (WinRT).
5413** But for all other platforms, it is highly recommended that applications
5414** neither read nor write this variable. This global variable is a relic
5415** that exists for backwards compatibility of legacy applications and should
5416** be avoided in new projects.
5417**
5418** It is not safe to read or modify this variable in more than one
5419** thread at a time. It is not safe to read or modify this variable
5420** if a [database connection] is being used at the same time in a separate
5421** thread.
5422** It is intended that this variable be set once
5423** as part of process initialization and before any SQLite interface
5424** routines have been called and that this variable remain unchanged
5425** thereafter.
5426**
5427** ^The [temp_store_directory pragma] may modify this variable and cause
5428** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
5429** the [temp_store_directory pragma] always assumes that any string
5430** that this variable points to is held in memory obtained from
5431** [sqlite3_malloc] and the pragma may attempt to free that memory
5432** using [sqlite3_free].
5433** Hence, if this variable is modified directly, either it should be
5434** made NULL or made to point to memory obtained from [sqlite3_malloc]
5435** or else the use of the [temp_store_directory pragma] should be avoided.
5436** Except when requested by the [temp_store_directory pragma], SQLite
5437** does not free the memory that sqlite3_temp_directory points to. If
5438** the application wants that memory to be freed, it must do
5439** so itself, taking care to only do so after all [database connection]
5440** objects have been destroyed.
5441**
5442** <b>Note to Windows Runtime users:</b> The temporary directory must be set
5443** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various
5444** features that require the use of temporary files may fail. Here is an
5445** example of how to do this using C++ with the Windows Runtime:
5446**
5447** <blockquote><pre>
5448** LPCWSTR zPath = Windows::Storage::ApplicationData::Current->
5449** &nbsp; TemporaryFolder->Path->Data();
5450** char zPathBuf&#91;MAX_PATH + 1&#93;;
5451** memset(zPathBuf, 0, sizeof(zPathBuf));
5452** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf),
5453** &nbsp; NULL, NULL);
5454** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf);
5455** </pre></blockquote>
5456*/
5457SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory;
5458
5459/*
5460** CAPI3REF: Name Of The Folder Holding Database Files
5461**
5462** ^(If this global variable is made to point to a string which is
5463** the name of a folder (a.k.a. directory), then all database files
5464** specified with a relative pathname and created or accessed by
5465** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed
5466** to be relative to that directory.)^ ^If this variable is a NULL
5467** pointer, then SQLite assumes that all database files specified
5468** with a relative pathname are relative to the current directory
5469** for the process. Only the windows VFS makes use of this global
5470** variable; it is ignored by the unix VFS.
5471**
5472** Changing the value of this variable while a database connection is
5473** open can result in a corrupt database.
5474**
5475** It is not safe to read or modify this variable in more than one
5476** thread at a time. It is not safe to read or modify this variable
5477** if a [database connection] is being used at the same time in a separate
5478** thread.
5479** It is intended that this variable be set once
5480** as part of process initialization and before any SQLite interface
5481** routines have been called and that this variable remain unchanged
5482** thereafter.
5483**
5484** ^The [data_store_directory pragma] may modify this variable and cause
5485** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
5486** the [data_store_directory pragma] always assumes that any string
5487** that this variable points to is held in memory obtained from
5488** [sqlite3_malloc] and the pragma may attempt to free that memory
5489** using [sqlite3_free].
5490** Hence, if this variable is modified directly, either it should be
5491** made NULL or made to point to memory obtained from [sqlite3_malloc]
5492** or else the use of the [data_store_directory pragma] should be avoided.
5493*/
5494SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory;
5495
5496/*
5497** CAPI3REF: Test For Auto-Commit Mode
5498** KEYWORDS: {autocommit mode}
5499** METHOD: sqlite3
5500**
5501** ^The sqlite3_get_autocommit() interface returns non-zero or
5502** zero if the given database connection is or is not in autocommit mode,
5503** respectively. ^Autocommit mode is on by default.
5504** ^Autocommit mode is disabled by a [BEGIN] statement.
5505** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
5506**
5507** If certain kinds of errors occur on a statement within a multi-statement
5508** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
5509** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
5510** transaction might be rolled back automatically. The only way to
5511** find out whether SQLite automatically rolled back the transaction after
5512** an error is to use this function.
5513**
5514** If another thread changes the autocommit status of the database
5515** connection while this routine is running, then the return value
5516** is undefined.
5517*/
5518SQLITE_API int sqlite3_get_autocommit(sqlite3*);
5519
5520/*
5521** CAPI3REF: Find The Database Handle Of A Prepared Statement
5522** METHOD: sqlite3_stmt
5523**
5524** ^The sqlite3_db_handle interface returns the [database connection] handle
5525** to which a [prepared statement] belongs. ^The [database connection]
5526** returned by sqlite3_db_handle is the same [database connection]
5527** that was the first argument
5528** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
5529** create the statement in the first place.
5530*/
5531SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
5532
5533/*
5534** CAPI3REF: Return The Filename For A Database Connection
5535** METHOD: sqlite3
5536**
5537** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename
5538** associated with database N of connection D. ^The main database file
5539** has the name "main". If there is no attached database N on the database
5540** connection D, or if database N is a temporary or in-memory database, then
5541** a NULL pointer is returned.
5542**
5543** ^The filename returned by this function is the output of the
5544** xFullPathname method of the [VFS]. ^In other words, the filename
5545** will be an absolute pathname, even if the filename used
5546** to open the database originally was a URI or relative pathname.
5547*/
5548SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName);
5549
5550/*
5551** CAPI3REF: Determine if a database is read-only
5552** METHOD: sqlite3
5553**
5554** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N
5555** of connection D is read-only, 0 if it is read/write, or -1 if N is not
5556** the name of a database on connection D.
5557*/
5558SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName);
5559
5560/*
5561** CAPI3REF: Find the next prepared statement
5562** METHOD: sqlite3
5563**
5564** ^This interface returns a pointer to the next [prepared statement] after
5565** pStmt associated with the [database connection] pDb. ^If pStmt is NULL
5566** then this interface returns a pointer to the first prepared statement
5567** associated with the database connection pDb. ^If no prepared statement
5568** satisfies the conditions of this routine, it returns NULL.
5569**
5570** The [database connection] pointer D in a call to
5571** [sqlite3_next_stmt(D,S)] must refer to an open database
5572** connection and in particular must not be a NULL pointer.
5573*/
5574SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
5575
5576/*
5577** CAPI3REF: Commit And Rollback Notification Callbacks
5578** METHOD: sqlite3
5579**
5580** ^The sqlite3_commit_hook() interface registers a callback
5581** function to be invoked whenever a transaction is [COMMIT | committed].
5582** ^Any callback set by a previous call to sqlite3_commit_hook()
5583** for the same database connection is overridden.
5584** ^The sqlite3_rollback_hook() interface registers a callback
5585** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
5586** ^Any callback set by a previous call to sqlite3_rollback_hook()
5587** for the same database connection is overridden.
5588** ^The pArg argument is passed through to the callback.
5589** ^If the callback on a commit hook function returns non-zero,
5590** then the commit is converted into a rollback.
5591**
5592** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
5593** return the P argument from the previous call of the same function
5594** on the same [database connection] D, or NULL for
5595** the first call for each function on D.
5596**
5597** The commit and rollback hook callbacks are not reentrant.
5598** The callback implementation must not do anything that will modify
5599** the database connection that invoked the callback. Any actions
5600** to modify the database connection must be deferred until after the
5601** completion of the [sqlite3_step()] call that triggered the commit
5602** or rollback hook in the first place.
5603** Note that running any other SQL statements, including SELECT statements,
5604** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify
5605** the database connections for the meaning of "modify" in this paragraph.
5606**
5607** ^Registering a NULL function disables the callback.
5608**
5609** ^When the commit hook callback routine returns zero, the [COMMIT]
5610** operation is allowed to continue normally. ^If the commit hook
5611** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
5612** ^The rollback hook is invoked on a rollback that results from a commit
5613** hook returning non-zero, just as it would be with any other rollback.
5614**
5615** ^For the purposes of this API, a transaction is said to have been
5616** rolled back if an explicit "ROLLBACK" statement is executed, or
5617** an error or constraint causes an implicit rollback to occur.
5618** ^The rollback callback is not invoked if a transaction is
5619** automatically rolled back because the database connection is closed.
5620**
5621** See also the [sqlite3_update_hook()] interface.
5622*/
5623SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
5624SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
5625
5626/*
5627** CAPI3REF: Data Change Notification Callbacks
5628** METHOD: sqlite3
5629**
5630** ^The sqlite3_update_hook() interface registers a callback function
5631** with the [database connection] identified by the first argument
5632** to be invoked whenever a row is updated, inserted or deleted in
5633** a [rowid table].
5634** ^Any callback set by a previous call to this function
5635** for the same database connection is overridden.
5636**
5637** ^The second argument is a pointer to the function to invoke when a
5638** row is updated, inserted or deleted in a rowid table.
5639** ^The first argument to the callback is a copy of the third argument
5640** to sqlite3_update_hook().
5641** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
5642** or [SQLITE_UPDATE], depending on the operation that caused the callback
5643** to be invoked.
5644** ^The third and fourth arguments to the callback contain pointers to the
5645** database and table name containing the affected row.
5646** ^The final callback parameter is the [rowid] of the row.
5647** ^In the case of an update, this is the [rowid] after the update takes place.
5648**
5649** ^(The update hook is not invoked when internal system tables are
5650** modified (i.e. sqlite_master and sqlite_sequence).)^
5651** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified.
5652**
5653** ^In the current implementation, the update hook
5654** is not invoked when conflicting rows are deleted because of an
5655** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook
5656** invoked when rows are deleted using the [truncate optimization].
5657** The exceptions defined in this paragraph might change in a future
5658** release of SQLite.
5659**
5660** The update hook implementation must not do anything that will modify
5661** the database connection that invoked the update hook. Any actions
5662** to modify the database connection must be deferred until after the
5663** completion of the [sqlite3_step()] call that triggered the update hook.
5664** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
5665** database connections for the meaning of "modify" in this paragraph.
5666**
5667** ^The sqlite3_update_hook(D,C,P) function
5668** returns the P argument from the previous call
5669** on the same [database connection] D, or NULL for
5670** the first call on D.
5671**
5672** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()],
5673** and [sqlite3_preupdate_hook()] interfaces.
5674*/
5675SQLITE_API void *sqlite3_update_hook(
5676 sqlite3*,
5677 void(*)(void *,int ,char const *,char const *,sqlite3_int64),
5678 void*
5679);
5680
5681/*
5682** CAPI3REF: Enable Or Disable Shared Pager Cache
5683**
5684** ^(This routine enables or disables the sharing of the database cache
5685** and schema data structures between [database connection | connections]
5686** to the same database. Sharing is enabled if the argument is true
5687** and disabled if the argument is false.)^
5688**
5689** ^Cache sharing is enabled and disabled for an entire process.
5690** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]).
5691** In prior versions of SQLite,
5692** sharing was enabled or disabled for each thread separately.
5693**
5694** ^(The cache sharing mode set by this interface effects all subsequent
5695** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
5696** Existing database connections continue use the sharing mode
5697** that was in effect at the time they were opened.)^
5698**
5699** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
5700** successfully. An [error code] is returned otherwise.)^
5701**
5702** ^Shared cache is disabled by default. But this might change in
5703** future releases of SQLite. Applications that care about shared
5704** cache setting should set it explicitly.
5705**
5706** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0
5707** and will always return SQLITE_MISUSE. On those systems,
5708** shared cache mode should be enabled per-database connection via
5709** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE].
5710**
5711** This interface is threadsafe on processors where writing a
5712** 32-bit integer is atomic.
5713**
5714** See Also: [SQLite Shared-Cache Mode]
5715*/
5716SQLITE_API int sqlite3_enable_shared_cache(int);
5717
5718/*
5719** CAPI3REF: Attempt To Free Heap Memory
5720**
5721** ^The sqlite3_release_memory() interface attempts to free N bytes
5722** of heap memory by deallocating non-essential memory allocations
5723** held by the database library. Memory used to cache database
5724** pages to improve performance is an example of non-essential memory.
5725** ^sqlite3_release_memory() returns the number of bytes actually freed,
5726** which might be more or less than the amount requested.
5727** ^The sqlite3_release_memory() routine is a no-op returning zero
5728** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
5729**
5730** See also: [sqlite3_db_release_memory()]
5731*/
5732SQLITE_API int sqlite3_release_memory(int);
5733
5734/*
5735** CAPI3REF: Free Memory Used By A Database Connection
5736** METHOD: sqlite3
5737**
5738** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap
5739** memory as possible from database connection D. Unlike the
5740** [sqlite3_release_memory()] interface, this interface is in effect even
5741** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is
5742** omitted.
5743**
5744** See also: [sqlite3_release_memory()]
5745*/
5746SQLITE_API int sqlite3_db_release_memory(sqlite3*);
5747
5748/*
5749** CAPI3REF: Impose A Limit On Heap Size
5750**
5751** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the
5752** soft limit on the amount of heap memory that may be allocated by SQLite.
5753** ^SQLite strives to keep heap memory utilization below the soft heap
5754** limit by reducing the number of pages held in the page cache
5755** as heap memory usages approaches the limit.
5756** ^The soft heap limit is "soft" because even though SQLite strives to stay
5757** below the limit, it will exceed the limit rather than generate
5758** an [SQLITE_NOMEM] error. In other words, the soft heap limit
5759** is advisory only.
5760**
5761** ^The return value from sqlite3_soft_heap_limit64() is the size of
5762** the soft heap limit prior to the call, or negative in the case of an
5763** error. ^If the argument N is negative
5764** then no change is made to the soft heap limit. Hence, the current
5765** size of the soft heap limit can be determined by invoking
5766** sqlite3_soft_heap_limit64() with a negative argument.
5767**
5768** ^If the argument N is zero then the soft heap limit is disabled.
5769**
5770** ^(The soft heap limit is not enforced in the current implementation
5771** if one or more of following conditions are true:
5772**
5773** <ul>
5774** <li> The soft heap limit is set to zero.
5775** <li> Memory accounting is disabled using a combination of the
5776** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
5777** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
5778** <li> An alternative page cache implementation is specified using
5779** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...).
5780** <li> The page cache allocates from its own memory pool supplied
5781** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
5782** from the heap.
5783** </ul>)^
5784**
5785** Beginning with SQLite [version 3.7.3] ([dateof:3.7.3]),
5786** the soft heap limit is enforced
5787** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT]
5788** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT],
5789** the soft heap limit is enforced on every memory allocation. Without
5790** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced
5791** when memory is allocated by the page cache. Testing suggests that because
5792** the page cache is the predominate memory user in SQLite, most
5793** applications will achieve adequate soft heap limit enforcement without
5794** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT].
5795**
5796** The circumstances under which SQLite will enforce the soft heap limit may
5797** changes in future releases of SQLite.
5798*/
5799SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N);
5800
5801/*
5802** CAPI3REF: Deprecated Soft Heap Limit Interface
5803** DEPRECATED
5804**
5805** This is a deprecated version of the [sqlite3_soft_heap_limit64()]
5806** interface. This routine is provided for historical compatibility
5807** only. All new applications should use the
5808** [sqlite3_soft_heap_limit64()] interface rather than this one.
5809*/
5810SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N);
5811
5812
5813/*
5814** CAPI3REF: Extract Metadata About A Column Of A Table
5815** METHOD: sqlite3
5816**
5817** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns
5818** information about column C of table T in database D
5819** on [database connection] X.)^ ^The sqlite3_table_column_metadata()
5820** interface returns SQLITE_OK and fills in the non-NULL pointers in
5821** the final five arguments with appropriate values if the specified
5822** column exists. ^The sqlite3_table_column_metadata() interface returns
5823** SQLITE_ERROR and if the specified column does not exist.
5824** ^If the column-name parameter to sqlite3_table_column_metadata() is a
5825** NULL pointer, then this routine simply checks for the existence of the
5826** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it
5827** does not. If the table name parameter T in a call to
5828** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is
5829** undefined behavior.
5830**
5831** ^The column is identified by the second, third and fourth parameters to
5832** this function. ^(The second parameter is either the name of the database
5833** (i.e. "main", "temp", or an attached database) containing the specified
5834** table or NULL.)^ ^If it is NULL, then all attached databases are searched
5835** for the table using the same algorithm used by the database engine to
5836** resolve unqualified table references.
5837**
5838** ^The third and fourth parameters to this function are the table and column
5839** name of the desired column, respectively.
5840**
5841** ^Metadata is returned by writing to the memory locations passed as the 5th
5842** and subsequent parameters to this function. ^Any of these arguments may be
5843** NULL, in which case the corresponding element of metadata is omitted.
5844**
5845** ^(<blockquote>
5846** <table border="1">
5847** <tr><th> Parameter <th> Output<br>Type <th> Description
5848**
5849** <tr><td> 5th <td> const char* <td> Data type
5850** <tr><td> 6th <td> const char* <td> Name of default collation sequence
5851** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint
5852** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY
5853** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT]
5854** </table>
5855** </blockquote>)^
5856**
5857** ^The memory pointed to by the character pointers returned for the
5858** declaration type and collation sequence is valid until the next
5859** call to any SQLite API function.
5860**
5861** ^If the specified table is actually a view, an [error code] is returned.
5862**
5863** ^If the specified column is "rowid", "oid" or "_rowid_" and the table
5864** is not a [WITHOUT ROWID] table and an
5865** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
5866** parameters are set for the explicitly declared column. ^(If there is no
5867** [INTEGER PRIMARY KEY] column, then the outputs
5868** for the [rowid] are set as follows:
5869**
5870** <pre>
5871** data type: "INTEGER"
5872** collation sequence: "BINARY"
5873** not null: 0
5874** primary key: 1
5875** auto increment: 0
5876** </pre>)^
5877**
5878** ^This function causes all database schemas to be read from disk and
5879** parsed, if that has not already been done, and returns an error if
5880** any errors are encountered while loading the schema.
5881*/
5882SQLITE_API int sqlite3_table_column_metadata(
5883 sqlite3 *db, /* Connection handle */
5884 const char *zDbName, /* Database name or NULL */
5885 const char *zTableName, /* Table name */
5886 const char *zColumnName, /* Column name */
5887 char const **pzDataType, /* OUTPUT: Declared data type */
5888 char const **pzCollSeq, /* OUTPUT: Collation sequence name */
5889 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */
5890 int *pPrimaryKey, /* OUTPUT: True if column part of PK */
5891 int *pAutoinc /* OUTPUT: True if column is auto-increment */
5892);
5893
5894/*
5895** CAPI3REF: Load An Extension
5896** METHOD: sqlite3
5897**
5898** ^This interface loads an SQLite extension library from the named file.
5899**
5900** ^The sqlite3_load_extension() interface attempts to load an
5901** [SQLite extension] library contained in the file zFile. If
5902** the file cannot be loaded directly, attempts are made to load
5903** with various operating-system specific extensions added.
5904** So for example, if "samplelib" cannot be loaded, then names like
5905** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might
5906** be tried also.
5907**
5908** ^The entry point is zProc.
5909** ^(zProc may be 0, in which case SQLite will try to come up with an
5910** entry point name on its own. It first tries "sqlite3_extension_init".
5911** If that does not work, it constructs a name "sqlite3_X_init" where the
5912** X is consists of the lower-case equivalent of all ASCII alphabetic
5913** characters in the filename from the last "/" to the first following
5914** "." and omitting any initial "lib".)^
5915** ^The sqlite3_load_extension() interface returns
5916** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
5917** ^If an error occurs and pzErrMsg is not 0, then the
5918** [sqlite3_load_extension()] interface shall attempt to
5919** fill *pzErrMsg with error message text stored in memory
5920** obtained from [sqlite3_malloc()]. The calling function
5921** should free this memory by calling [sqlite3_free()].
5922**
5923** ^Extension loading must be enabled using
5924** [sqlite3_enable_load_extension()] or
5925** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL)
5926** prior to calling this API,
5927** otherwise an error will be returned.
5928**
5929** <b>Security warning:</b> It is recommended that the
5930** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this
5931** interface. The use of the [sqlite3_enable_load_extension()] interface
5932** should be avoided. This will keep the SQL function [load_extension()]
5933** disabled and prevent SQL injections from giving attackers
5934** access to extension loading capabilities.
5935**
5936** See also the [load_extension() SQL function].
5937*/
5938SQLITE_API int sqlite3_load_extension(
5939 sqlite3 *db, /* Load the extension into this database connection */
5940 const char *zFile, /* Name of the shared library containing extension */
5941 const char *zProc, /* Entry point. Derived from zFile if 0 */
5942 char **pzErrMsg /* Put error message here if not 0 */
5943);
5944
5945/*
5946** CAPI3REF: Enable Or Disable Extension Loading
5947** METHOD: sqlite3
5948**
5949** ^So as not to open security holes in older applications that are
5950** unprepared to deal with [extension loading], and as a means of disabling
5951** [extension loading] while evaluating user-entered SQL, the following API
5952** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
5953**
5954** ^Extension loading is off by default.
5955** ^Call the sqlite3_enable_load_extension() routine with onoff==1
5956** to turn extension loading on and call it with onoff==0 to turn
5957** it back off again.
5958**
5959** ^This interface enables or disables both the C-API
5960** [sqlite3_load_extension()] and the SQL function [load_extension()].
5961** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..)
5962** to enable or disable only the C-API.)^
5963**
5964** <b>Security warning:</b> It is recommended that extension loading
5965** be disabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method
5966** rather than this interface, so the [load_extension()] SQL function
5967** remains disabled. This will prevent SQL injections from giving attackers
5968** access to extension loading capabilities.
5969*/
5970SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
5971
5972/*
5973** CAPI3REF: Automatically Load Statically Linked Extensions
5974**
5975** ^This interface causes the xEntryPoint() function to be invoked for
5976** each new [database connection] that is created. The idea here is that
5977** xEntryPoint() is the entry point for a statically linked [SQLite extension]
5978** that is to be automatically loaded into all new database connections.
5979**
5980** ^(Even though the function prototype shows that xEntryPoint() takes
5981** no arguments and returns void, SQLite invokes xEntryPoint() with three
5982** arguments and expects an integer result as if the signature of the
5983** entry point where as follows:
5984**
5985** <blockquote><pre>
5986** &nbsp; int xEntryPoint(
5987** &nbsp; sqlite3 *db,
5988** &nbsp; const char **pzErrMsg,
5989** &nbsp; const struct sqlite3_api_routines *pThunk
5990** &nbsp; );
5991** </pre></blockquote>)^
5992**
5993** If the xEntryPoint routine encounters an error, it should make *pzErrMsg
5994** point to an appropriate error message (obtained from [sqlite3_mprintf()])
5995** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg
5996** is NULL before calling the xEntryPoint(). ^SQLite will invoke
5997** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any
5998** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],
5999** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.
6000**
6001** ^Calling sqlite3_auto_extension(X) with an entry point X that is already
6002** on the list of automatic extensions is a harmless no-op. ^No entry point
6003** will be called more than once for each database connection that is opened.
6004**
6005** See also: [sqlite3_reset_auto_extension()]
6006** and [sqlite3_cancel_auto_extension()]
6007*/
6008SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void));
6009
6010/*
6011** CAPI3REF: Cancel Automatic Extension Loading
6012**
6013** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the
6014** initialization routine X that was registered using a prior call to
6015** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)]
6016** routine returns 1 if initialization routine X was successfully
6017** unregistered and it returns 0 if X was not on the list of initialization
6018** routines.
6019*/
6020SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void));
6021
6022/*
6023** CAPI3REF: Reset Automatic Extension Loading
6024**
6025** ^This interface disables all automatic extensions previously
6026** registered using [sqlite3_auto_extension()].
6027*/
6028SQLITE_API void sqlite3_reset_auto_extension(void);
6029
6030/*
6031** The interface to the virtual-table mechanism is currently considered
6032** to be experimental. The interface might change in incompatible ways.
6033** If this is a problem for you, do not use the interface at this time.
6034**
6035** When the virtual-table mechanism stabilizes, we will declare the
6036** interface fixed, support it indefinitely, and remove this comment.
6037*/
6038
6039/*
6040** Structures used by the virtual table interface
6041*/
6042typedef struct sqlite3_vtab sqlite3_vtab;
6043typedef struct sqlite3_index_info sqlite3_index_info;
6044typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
6045typedef struct sqlite3_module sqlite3_module;
6046
6047/*
6048** CAPI3REF: Virtual Table Object
6049** KEYWORDS: sqlite3_module {virtual table module}
6050**
6051** This structure, sometimes called a "virtual table module",
6052** defines the implementation of a [virtual tables].
6053** This structure consists mostly of methods for the module.
6054**
6055** ^A virtual table module is created by filling in a persistent
6056** instance of this structure and passing a pointer to that instance
6057** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
6058** ^The registration remains valid until it is replaced by a different
6059** module or until the [database connection] closes. The content
6060** of this structure must not change while it is registered with
6061** any database connection.
6062*/
6063struct sqlite3_module {
6064 int iVersion;
6065 int (*xCreate)(sqlite3*, void *pAux,
6066 int argc, const char *const*argv,
6067 sqlite3_vtab **ppVTab, char**);
6068 int (*xConnect)(sqlite3*, void *pAux,
6069 int argc, const char *const*argv,
6070 sqlite3_vtab **ppVTab, char**);
6071 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
6072 int (*xDisconnect)(sqlite3_vtab *pVTab);
6073 int (*xDestroy)(sqlite3_vtab *pVTab);
6074 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
6075 int (*xClose)(sqlite3_vtab_cursor*);
6076 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
6077 int argc, sqlite3_value **argv);
6078 int (*xNext)(sqlite3_vtab_cursor*);
6079 int (*xEof)(sqlite3_vtab_cursor*);
6080 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
6081 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
6082 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
6083 int (*xBegin)(sqlite3_vtab *pVTab);
6084 int (*xSync)(sqlite3_vtab *pVTab);
6085 int (*xCommit)(sqlite3_vtab *pVTab);
6086 int (*xRollback)(sqlite3_vtab *pVTab);
6087 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
6088 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
6089 void **ppArg);
6090 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
6091 /* The methods above are in version 1 of the sqlite_module object. Those
6092 ** below are for version 2 and greater. */
6093 int (*xSavepoint)(sqlite3_vtab *pVTab, int);
6094 int (*xRelease)(sqlite3_vtab *pVTab, int);
6095 int (*xRollbackTo)(sqlite3_vtab *pVTab, int);
6096};
6097
6098/*
6099** CAPI3REF: Virtual Table Indexing Information
6100** KEYWORDS: sqlite3_index_info
6101**
6102** The sqlite3_index_info structure and its substructures is used as part
6103** of the [virtual table] interface to
6104** pass information into and receive the reply from the [xBestIndex]
6105** method of a [virtual table module]. The fields under **Inputs** are the
6106** inputs to xBestIndex and are read-only. xBestIndex inserts its
6107** results into the **Outputs** fields.
6108**
6109** ^(The aConstraint[] array records WHERE clause constraints of the form:
6110**
6111** <blockquote>column OP expr</blockquote>
6112**
6113** where OP is =, &lt;, &lt;=, &gt;, or &gt;=.)^ ^(The particular operator is
6114** stored in aConstraint[].op using one of the
6115** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^
6116** ^(The index of the column is stored in
6117** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the
6118** expr on the right-hand side can be evaluated (and thus the constraint
6119** is usable) and false if it cannot.)^
6120**
6121** ^The optimizer automatically inverts terms of the form "expr OP column"
6122** and makes other simplifications to the WHERE clause in an attempt to
6123** get as many WHERE clause terms into the form shown above as possible.
6124** ^The aConstraint[] array only reports WHERE clause terms that are
6125** relevant to the particular virtual table being queried.
6126**
6127** ^Information about the ORDER BY clause is stored in aOrderBy[].
6128** ^Each term of aOrderBy records a column of the ORDER BY clause.
6129**
6130** The colUsed field indicates which columns of the virtual table may be
6131** required by the current scan. Virtual table columns are numbered from
6132** zero in the order in which they appear within the CREATE TABLE statement
6133** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62),
6134** the corresponding bit is set within the colUsed mask if the column may be
6135** required by SQLite. If the table has at least 64 columns and any column
6136** to the right of the first 63 is required, then bit 63 of colUsed is also
6137** set. In other words, column iCol may be required if the expression
6138** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to
6139** non-zero.
6140**
6141** The [xBestIndex] method must fill aConstraintUsage[] with information
6142** about what parameters to pass to xFilter. ^If argvIndex>0 then
6143** the right-hand side of the corresponding aConstraint[] is evaluated
6144** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit
6145** is true, then the constraint is assumed to be fully handled by the
6146** virtual table and is not checked again by SQLite.)^
6147**
6148** ^The idxNum and idxPtr values are recorded and passed into the
6149** [xFilter] method.
6150** ^[sqlite3_free()] is used to free idxPtr if and only if
6151** needToFreeIdxPtr is true.
6152**
6153** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
6154** the correct order to satisfy the ORDER BY clause so that no separate
6155** sorting step is required.
6156**
6157** ^The estimatedCost value is an estimate of the cost of a particular
6158** strategy. A cost of N indicates that the cost of the strategy is similar
6159** to a linear scan of an SQLite table with N rows. A cost of log(N)
6160** indicates that the expense of the operation is similar to that of a
6161** binary search on a unique indexed field of an SQLite table with N rows.
6162**
6163** ^The estimatedRows value is an estimate of the number of rows that
6164** will be returned by the strategy.
6165**
6166** The xBestIndex method may optionally populate the idxFlags field with a
6167** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag -
6168** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite
6169** assumes that the strategy may visit at most one row.
6170**
6171** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then
6172** SQLite also assumes that if a call to the xUpdate() method is made as
6173** part of the same statement to delete or update a virtual table row and the
6174** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback
6175** any database changes. In other words, if the xUpdate() returns
6176** SQLITE_CONSTRAINT, the database contents must be exactly as they were
6177** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not
6178** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by
6179** the xUpdate method are automatically rolled back by SQLite.
6180**
6181** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info
6182** structure for SQLite [version 3.8.2] ([dateof:3.8.2]).
6183** If a virtual table extension is
6184** used with an SQLite version earlier than 3.8.2, the results of attempting
6185** to read or write the estimatedRows field are undefined (but are likely
6186** to included crashing the application). The estimatedRows field should
6187** therefore only be used if [sqlite3_libversion_number()] returns a
6188** value greater than or equal to 3008002. Similarly, the idxFlags field
6189** was added for [version 3.9.0] ([dateof:3.9.0]).
6190** It may therefore only be used if
6191** sqlite3_libversion_number() returns a value greater than or equal to
6192** 3009000.
6193*/
6194struct sqlite3_index_info {
6195 /* Inputs */
6196 int nConstraint; /* Number of entries in aConstraint */
6197 struct sqlite3_index_constraint {
6198 int iColumn; /* Column constrained. -1 for ROWID */
6199 unsigned char op; /* Constraint operator */
6200 unsigned char usable; /* True if this constraint is usable */
6201 int iTermOffset; /* Used internally - xBestIndex should ignore */
6202 } *aConstraint; /* Table of WHERE clause constraints */
6203 int nOrderBy; /* Number of terms in the ORDER BY clause */
6204 struct sqlite3_index_orderby {
6205 int iColumn; /* Column number */
6206 unsigned char desc; /* True for DESC. False for ASC. */
6207 } *aOrderBy; /* The ORDER BY clause */
6208 /* Outputs */
6209 struct sqlite3_index_constraint_usage {
6210 int argvIndex; /* if >0, constraint is part of argv to xFilter */
6211 unsigned char omit; /* Do not code a test for this constraint */
6212 } *aConstraintUsage;
6213 int idxNum; /* Number used to identify the index */
6214 char *idxStr; /* String, possibly obtained from sqlite3_malloc */
6215 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */
6216 int orderByConsumed; /* True if output is already ordered */
6217 double estimatedCost; /* Estimated cost of using this index */
6218 /* Fields below are only available in SQLite 3.8.2 and later */
6219 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */
6220 /* Fields below are only available in SQLite 3.9.0 and later */
6221 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */
6222 /* Fields below are only available in SQLite 3.10.0 and later */
6223 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */
6224};
6225
6226/*
6227** CAPI3REF: Virtual Table Scan Flags
6228*/
6229#define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */
6230
6231/*
6232** CAPI3REF: Virtual Table Constraint Operator Codes
6233**
6234** These macros defined the allowed values for the
6235** [sqlite3_index_info].aConstraint[].op field. Each value represents
6236** an operator that is part of a constraint term in the wHERE clause of
6237** a query that uses a [virtual table].
6238*/
6239#define SQLITE_INDEX_CONSTRAINT_EQ 2
6240#define SQLITE_INDEX_CONSTRAINT_GT 4
6241#define SQLITE_INDEX_CONSTRAINT_LE 8
6242#define SQLITE_INDEX_CONSTRAINT_LT 16
6243#define SQLITE_INDEX_CONSTRAINT_GE 32
6244#define SQLITE_INDEX_CONSTRAINT_MATCH 64
6245#define SQLITE_INDEX_CONSTRAINT_LIKE 65
6246#define SQLITE_INDEX_CONSTRAINT_GLOB 66
6247#define SQLITE_INDEX_CONSTRAINT_REGEXP 67
6248#define SQLITE_INDEX_CONSTRAINT_NE 68
6249#define SQLITE_INDEX_CONSTRAINT_ISNOT 69
6250#define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70
6251#define SQLITE_INDEX_CONSTRAINT_ISNULL 71
6252#define SQLITE_INDEX_CONSTRAINT_IS 72
6253
6254/*
6255** CAPI3REF: Register A Virtual Table Implementation
6256** METHOD: sqlite3
6257**
6258** ^These routines are used to register a new [virtual table module] name.
6259** ^Module names must be registered before
6260** creating a new [virtual table] using the module and before using a
6261** preexisting [virtual table] for the module.
6262**
6263** ^The module name is registered on the [database connection] specified
6264** by the first parameter. ^The name of the module is given by the
6265** second parameter. ^The third parameter is a pointer to
6266** the implementation of the [virtual table module]. ^The fourth
6267** parameter is an arbitrary client data pointer that is passed through
6268** into the [xCreate] and [xConnect] methods of the virtual table module
6269** when a new virtual table is be being created or reinitialized.
6270**
6271** ^The sqlite3_create_module_v2() interface has a fifth parameter which
6272** is a pointer to a destructor for the pClientData. ^SQLite will
6273** invoke the destructor function (if it is not NULL) when SQLite
6274** no longer needs the pClientData pointer. ^The destructor will also
6275** be invoked if the call to sqlite3_create_module_v2() fails.
6276** ^The sqlite3_create_module()
6277** interface is equivalent to sqlite3_create_module_v2() with a NULL
6278** destructor.
6279*/
6280SQLITE_API int sqlite3_create_module(
6281 sqlite3 *db, /* SQLite connection to register module with */
6282 const char *zName, /* Name of the module */
6283 const sqlite3_module *p, /* Methods for the module */
6284 void *pClientData /* Client data for xCreate/xConnect */
6285);
6286SQLITE_API int sqlite3_create_module_v2(
6287 sqlite3 *db, /* SQLite connection to register module with */
6288 const char *zName, /* Name of the module */
6289 const sqlite3_module *p, /* Methods for the module */
6290 void *pClientData, /* Client data for xCreate/xConnect */
6291 void(*xDestroy)(void*) /* Module destructor function */
6292);
6293
6294/*
6295** CAPI3REF: Virtual Table Instance Object
6296** KEYWORDS: sqlite3_vtab
6297**
6298** Every [virtual table module] implementation uses a subclass
6299** of this object to describe a particular instance
6300** of the [virtual table]. Each subclass will
6301** be tailored to the specific needs of the module implementation.
6302** The purpose of this superclass is to define certain fields that are
6303** common to all module implementations.
6304**
6305** ^Virtual tables methods can set an error message by assigning a
6306** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should
6307** take care that any prior string is freed by a call to [sqlite3_free()]
6308** prior to assigning a new string to zErrMsg. ^After the error message
6309** is delivered up to the client application, the string will be automatically
6310** freed by sqlite3_free() and the zErrMsg field will be zeroed.
6311*/
6312struct sqlite3_vtab {
6313 const sqlite3_module *pModule; /* The module for this virtual table */
6314 int nRef; /* Number of open cursors */
6315 char *zErrMsg; /* Error message from sqlite3_mprintf() */
6316 /* Virtual table implementations will typically add additional fields */
6317};
6318
6319/*
6320** CAPI3REF: Virtual Table Cursor Object
6321** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
6322**
6323** Every [virtual table module] implementation uses a subclass of the
6324** following structure to describe cursors that point into the
6325** [virtual table] and are used
6326** to loop through the virtual table. Cursors are created using the
6327** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
6328** by the [sqlite3_module.xClose | xClose] method. Cursors are used
6329** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
6330** of the module. Each module implementation will define
6331** the content of a cursor structure to suit its own needs.
6332**
6333** This superclass exists in order to define fields of the cursor that
6334** are common to all implementations.
6335*/
6336struct sqlite3_vtab_cursor {
6337 sqlite3_vtab *pVtab; /* Virtual table of this cursor */
6338 /* Virtual table implementations will typically add additional fields */
6339};
6340
6341/*
6342** CAPI3REF: Declare The Schema Of A Virtual Table
6343**
6344** ^The [xCreate] and [xConnect] methods of a
6345** [virtual table module] call this interface
6346** to declare the format (the names and datatypes of the columns) of
6347** the virtual tables they implement.
6348*/
6349SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL);
6350
6351/*
6352** CAPI3REF: Overload A Function For A Virtual Table
6353** METHOD: sqlite3
6354**
6355** ^(Virtual tables can provide alternative implementations of functions
6356** using the [xFindFunction] method of the [virtual table module].
6357** But global versions of those functions
6358** must exist in order to be overloaded.)^
6359**
6360** ^(This API makes sure a global version of a function with a particular
6361** name and number of parameters exists. If no such function exists
6362** before this API is called, a new function is created.)^ ^The implementation
6363** of the new function always causes an exception to be thrown. So
6364** the new function is not good for anything by itself. Its only
6365** purpose is to be a placeholder function that can be overloaded
6366** by a [virtual table].
6367*/
6368SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
6369
6370/*
6371** The interface to the virtual-table mechanism defined above (back up
6372** to a comment remarkably similar to this one) is currently considered
6373** to be experimental. The interface might change in incompatible ways.
6374** If this is a problem for you, do not use the interface at this time.
6375**
6376** When the virtual-table mechanism stabilizes, we will declare the
6377** interface fixed, support it indefinitely, and remove this comment.
6378*/
6379
6380/*
6381** CAPI3REF: A Handle To An Open BLOB
6382** KEYWORDS: {BLOB handle} {BLOB handles}
6383**
6384** An instance of this object represents an open BLOB on which
6385** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
6386** ^Objects of this type are created by [sqlite3_blob_open()]
6387** and destroyed by [sqlite3_blob_close()].
6388** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
6389** can be used to read or write small subsections of the BLOB.
6390** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
6391*/
6392typedef struct sqlite3_blob sqlite3_blob;
6393
6394/*
6395** CAPI3REF: Open A BLOB For Incremental I/O
6396** METHOD: sqlite3
6397** CONSTRUCTOR: sqlite3_blob
6398**
6399** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
6400** in row iRow, column zColumn, table zTable in database zDb;
6401** in other words, the same BLOB that would be selected by:
6402**
6403** <pre>
6404** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
6405** </pre>)^
6406**
6407** ^(Parameter zDb is not the filename that contains the database, but
6408** rather the symbolic name of the database. For attached databases, this is
6409** the name that appears after the AS keyword in the [ATTACH] statement.
6410** For the main database file, the database name is "main". For TEMP
6411** tables, the database name is "temp".)^
6412**
6413** ^If the flags parameter is non-zero, then the BLOB is opened for read
6414** and write access. ^If the flags parameter is zero, the BLOB is opened for
6415** read-only access.
6416**
6417** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored
6418** in *ppBlob. Otherwise an [error code] is returned and, unless the error
6419** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided
6420** the API is not misused, it is always safe to call [sqlite3_blob_close()]
6421** on *ppBlob after this function it returns.
6422**
6423** This function fails with SQLITE_ERROR if any of the following are true:
6424** <ul>
6425** <li> ^(Database zDb does not exist)^,
6426** <li> ^(Table zTable does not exist within database zDb)^,
6427** <li> ^(Table zTable is a WITHOUT ROWID table)^,
6428** <li> ^(Column zColumn does not exist)^,
6429** <li> ^(Row iRow is not present in the table)^,
6430** <li> ^(The specified column of row iRow contains a value that is not
6431** a TEXT or BLOB value)^,
6432** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE
6433** constraint and the blob is being opened for read/write access)^,
6434** <li> ^([foreign key constraints | Foreign key constraints] are enabled,
6435** column zColumn is part of a [child key] definition and the blob is
6436** being opened for read/write access)^.
6437** </ul>
6438**
6439** ^Unless it returns SQLITE_MISUSE, this function sets the
6440** [database connection] error code and message accessible via
6441** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
6442**
6443** A BLOB referenced by sqlite3_blob_open() may be read using the
6444** [sqlite3_blob_read()] interface and modified by using
6445** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a
6446** different row of the same table using the [sqlite3_blob_reopen()]
6447** interface. However, the column, table, or database of a [BLOB handle]
6448** cannot be changed after the [BLOB handle] is opened.
6449**
6450** ^(If the row that a BLOB handle points to is modified by an
6451** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
6452** then the BLOB handle is marked as "expired".
6453** This is true if any column of the row is changed, even a column
6454** other than the one the BLOB handle is open on.)^
6455** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
6456** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
6457** ^(Changes written into a BLOB prior to the BLOB expiring are not
6458** rolled back by the expiration of the BLOB. Such changes will eventually
6459** commit if the transaction continues to completion.)^
6460**
6461** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
6462** the opened blob. ^The size of a blob may not be changed by this
6463** interface. Use the [UPDATE] SQL command to change the size of a
6464** blob.
6465**
6466** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
6467** and the built-in [zeroblob] SQL function may be used to create a
6468** zero-filled blob to read or write using the incremental-blob interface.
6469**
6470** To avoid a resource leak, every open [BLOB handle] should eventually
6471** be released by a call to [sqlite3_blob_close()].
6472**
6473** See also: [sqlite3_blob_close()],
6474** [sqlite3_blob_reopen()], [sqlite3_blob_read()],
6475** [sqlite3_blob_bytes()], [sqlite3_blob_write()].
6476*/
6477SQLITE_API int sqlite3_blob_open(
6478 sqlite3*,
6479 const char *zDb,
6480 const char *zTable,
6481 const char *zColumn,
6482 sqlite3_int64 iRow,
6483 int flags,
6484 sqlite3_blob **ppBlob
6485);
6486
6487/*
6488** CAPI3REF: Move a BLOB Handle to a New Row
6489** METHOD: sqlite3_blob
6490**
6491** ^This function is used to move an existing [BLOB handle] so that it points
6492** to a different row of the same database table. ^The new row is identified
6493** by the rowid value passed as the second argument. Only the row can be
6494** changed. ^The database, table and column on which the blob handle is open
6495** remain the same. Moving an existing [BLOB handle] to a new row is
6496** faster than closing the existing handle and opening a new one.
6497**
6498** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
6499** it must exist and there must be either a blob or text value stored in
6500** the nominated column.)^ ^If the new row is not present in the table, or if
6501** it does not contain a blob or text value, or if another error occurs, an
6502** SQLite error code is returned and the blob handle is considered aborted.
6503** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or
6504** [sqlite3_blob_reopen()] on an aborted blob handle immediately return
6505** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
6506** always returns zero.
6507**
6508** ^This function sets the database handle error code and message.
6509*/
6510SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
6511
6512/*
6513** CAPI3REF: Close A BLOB Handle
6514** DESTRUCTOR: sqlite3_blob
6515**
6516** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed
6517** unconditionally. Even if this routine returns an error code, the
6518** handle is still closed.)^
6519**
6520** ^If the blob handle being closed was opened for read-write access, and if
6521** the database is in auto-commit mode and there are no other open read-write
6522** blob handles or active write statements, the current transaction is
6523** committed. ^If an error occurs while committing the transaction, an error
6524** code is returned and the transaction rolled back.
6525**
6526** Calling this function with an argument that is not a NULL pointer or an
6527** open blob handle results in undefined behaviour. ^Calling this routine
6528** with a null pointer (such as would be returned by a failed call to
6529** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function
6530** is passed a valid open blob handle, the values returned by the
6531** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning.
6532*/
6533SQLITE_API int sqlite3_blob_close(sqlite3_blob *);
6534
6535/*
6536** CAPI3REF: Return The Size Of An Open BLOB
6537** METHOD: sqlite3_blob
6538**
6539** ^Returns the size in bytes of the BLOB accessible via the
6540** successfully opened [BLOB handle] in its only argument. ^The
6541** incremental blob I/O routines can only read or overwriting existing
6542** blob content; they cannot change the size of a blob.
6543**
6544** This routine only works on a [BLOB handle] which has been created
6545** by a prior successful call to [sqlite3_blob_open()] and which has not
6546** been closed by [sqlite3_blob_close()]. Passing any other pointer in
6547** to this routine results in undefined and probably undesirable behavior.
6548*/
6549SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *);
6550
6551/*
6552** CAPI3REF: Read Data From A BLOB Incrementally
6553** METHOD: sqlite3_blob
6554**
6555** ^(This function is used to read data from an open [BLOB handle] into a
6556** caller-supplied buffer. N bytes of data are copied into buffer Z
6557** from the open BLOB, starting at offset iOffset.)^
6558**
6559** ^If offset iOffset is less than N bytes from the end of the BLOB,
6560** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is
6561** less than zero, [SQLITE_ERROR] is returned and no data is read.
6562** ^The size of the blob (and hence the maximum value of N+iOffset)
6563** can be determined using the [sqlite3_blob_bytes()] interface.
6564**
6565** ^An attempt to read from an expired [BLOB handle] fails with an
6566** error code of [SQLITE_ABORT].
6567**
6568** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
6569** Otherwise, an [error code] or an [extended error code] is returned.)^
6570**
6571** This routine only works on a [BLOB handle] which has been created
6572** by a prior successful call to [sqlite3_blob_open()] and which has not
6573** been closed by [sqlite3_blob_close()]. Passing any other pointer in
6574** to this routine results in undefined and probably undesirable behavior.
6575**
6576** See also: [sqlite3_blob_write()].
6577*/
6578SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
6579
6580/*
6581** CAPI3REF: Write Data Into A BLOB Incrementally
6582** METHOD: sqlite3_blob
6583**
6584** ^(This function is used to write data into an open [BLOB handle] from a
6585** caller-supplied buffer. N bytes of data are copied from the buffer Z
6586** into the open BLOB, starting at offset iOffset.)^
6587**
6588** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
6589** Otherwise, an [error code] or an [extended error code] is returned.)^
6590** ^Unless SQLITE_MISUSE is returned, this function sets the
6591** [database connection] error code and message accessible via
6592** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
6593**
6594** ^If the [BLOB handle] passed as the first argument was not opened for
6595** writing (the flags parameter to [sqlite3_blob_open()] was zero),
6596** this function returns [SQLITE_READONLY].
6597**
6598** This function may only modify the contents of the BLOB; it is
6599** not possible to increase the size of a BLOB using this API.
6600** ^If offset iOffset is less than N bytes from the end of the BLOB,
6601** [SQLITE_ERROR] is returned and no data is written. The size of the
6602** BLOB (and hence the maximum value of N+iOffset) can be determined
6603** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less
6604** than zero [SQLITE_ERROR] is returned and no data is written.
6605**
6606** ^An attempt to write to an expired [BLOB handle] fails with an
6607** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred
6608** before the [BLOB handle] expired are not rolled back by the
6609** expiration of the handle, though of course those changes might
6610** have been overwritten by the statement that expired the BLOB handle
6611** or by other independent statements.
6612**
6613** This routine only works on a [BLOB handle] which has been created
6614** by a prior successful call to [sqlite3_blob_open()] and which has not
6615** been closed by [sqlite3_blob_close()]. Passing any other pointer in
6616** to this routine results in undefined and probably undesirable behavior.
6617**
6618** See also: [sqlite3_blob_read()].
6619*/
6620SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
6621
6622/*
6623** CAPI3REF: Virtual File System Objects
6624**
6625** A virtual filesystem (VFS) is an [sqlite3_vfs] object
6626** that SQLite uses to interact
6627** with the underlying operating system. Most SQLite builds come with a
6628** single default VFS that is appropriate for the host computer.
6629** New VFSes can be registered and existing VFSes can be unregistered.
6630** The following interfaces are provided.
6631**
6632** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
6633** ^Names are case sensitive.
6634** ^Names are zero-terminated UTF-8 strings.
6635** ^If there is no match, a NULL pointer is returned.
6636** ^If zVfsName is NULL then the default VFS is returned.
6637**
6638** ^New VFSes are registered with sqlite3_vfs_register().
6639** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
6640** ^The same VFS can be registered multiple times without injury.
6641** ^To make an existing VFS into the default VFS, register it again
6642** with the makeDflt flag set. If two different VFSes with the
6643** same name are registered, the behavior is undefined. If a
6644** VFS is registered with a name that is NULL or an empty string,
6645** then the behavior is undefined.
6646**
6647** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
6648** ^(If the default VFS is unregistered, another VFS is chosen as
6649** the default. The choice for the new VFS is arbitrary.)^
6650*/
6651SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
6652SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
6653SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
6654
6655/*
6656** CAPI3REF: Mutexes
6657**
6658** The SQLite core uses these routines for thread
6659** synchronization. Though they are intended for internal
6660** use by SQLite, code that links against SQLite is
6661** permitted to use any of these routines.
6662**
6663** The SQLite source code contains multiple implementations
6664** of these mutex routines. An appropriate implementation
6665** is selected automatically at compile-time. The following
6666** implementations are available in the SQLite core:
6667**
6668** <ul>
6669** <li> SQLITE_MUTEX_PTHREADS
6670** <li> SQLITE_MUTEX_W32
6671** <li> SQLITE_MUTEX_NOOP
6672** </ul>
6673**
6674** The SQLITE_MUTEX_NOOP implementation is a set of routines
6675** that does no real locking and is appropriate for use in
6676** a single-threaded application. The SQLITE_MUTEX_PTHREADS and
6677** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix
6678** and Windows.
6679**
6680** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
6681** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
6682** implementation is included with the library. In this case the
6683** application must supply a custom mutex implementation using the
6684** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
6685** before calling sqlite3_initialize() or any other public sqlite3_
6686** function that calls sqlite3_initialize().
6687**
6688** ^The sqlite3_mutex_alloc() routine allocates a new
6689** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc()
6690** routine returns NULL if it is unable to allocate the requested
6691** mutex. The argument to sqlite3_mutex_alloc() must one of these
6692** integer constants:
6693**
6694** <ul>
6695** <li> SQLITE_MUTEX_FAST
6696** <li> SQLITE_MUTEX_RECURSIVE
6697** <li> SQLITE_MUTEX_STATIC_MASTER
6698** <li> SQLITE_MUTEX_STATIC_MEM
6699** <li> SQLITE_MUTEX_STATIC_OPEN
6700** <li> SQLITE_MUTEX_STATIC_PRNG
6701** <li> SQLITE_MUTEX_STATIC_LRU
6702** <li> SQLITE_MUTEX_STATIC_PMEM
6703** <li> SQLITE_MUTEX_STATIC_APP1
6704** <li> SQLITE_MUTEX_STATIC_APP2
6705** <li> SQLITE_MUTEX_STATIC_APP3
6706** <li> SQLITE_MUTEX_STATIC_VFS1
6707** <li> SQLITE_MUTEX_STATIC_VFS2
6708** <li> SQLITE_MUTEX_STATIC_VFS3
6709** </ul>
6710**
6711** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
6712** cause sqlite3_mutex_alloc() to create
6713** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
6714** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
6715** The mutex implementation does not need to make a distinction
6716** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
6717** not want to. SQLite will only request a recursive mutex in
6718** cases where it really needs one. If a faster non-recursive mutex
6719** implementation is available on the host platform, the mutex subsystem
6720** might return such a mutex in response to SQLITE_MUTEX_FAST.
6721**
6722** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
6723** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
6724** a pointer to a static preexisting mutex. ^Nine static mutexes are
6725** used by the current version of SQLite. Future versions of SQLite
6726** may add additional static mutexes. Static mutexes are for internal
6727** use by SQLite only. Applications that use SQLite mutexes should
6728** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
6729** SQLITE_MUTEX_RECURSIVE.
6730**
6731** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
6732** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
6733** returns a different mutex on every call. ^For the static
6734** mutex types, the same mutex is returned on every call that has
6735** the same type number.
6736**
6737** ^The sqlite3_mutex_free() routine deallocates a previously
6738** allocated dynamic mutex. Attempting to deallocate a static
6739** mutex results in undefined behavior.
6740**
6741** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
6742** to enter a mutex. ^If another thread is already within the mutex,
6743** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
6744** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
6745** upon successful entry. ^(Mutexes created using
6746** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
6747** In such cases, the
6748** mutex must be exited an equal number of times before another thread
6749** can enter.)^ If the same thread tries to enter any mutex other
6750** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined.
6751**
6752** ^(Some systems (for example, Windows 95) do not support the operation
6753** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try()
6754** will always return SQLITE_BUSY. The SQLite core only ever uses
6755** sqlite3_mutex_try() as an optimization so this is acceptable
6756** behavior.)^
6757**
6758** ^The sqlite3_mutex_leave() routine exits a mutex that was
6759** previously entered by the same thread. The behavior
6760** is undefined if the mutex is not currently entered by the
6761** calling thread or is not currently allocated.
6762**
6763** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or
6764** sqlite3_mutex_leave() is a NULL pointer, then all three routines
6765** behave as no-ops.
6766**
6767** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
6768*/
6769SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int);
6770SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*);
6771SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*);
6772SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*);
6773SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*);
6774
6775/*
6776** CAPI3REF: Mutex Methods Object
6777**
6778** An instance of this structure defines the low-level routines
6779** used to allocate and use mutexes.
6780**
6781** Usually, the default mutex implementations provided by SQLite are
6782** sufficient, however the application has the option of substituting a custom
6783** implementation for specialized deployments or systems for which SQLite
6784** does not provide a suitable implementation. In this case, the application
6785** creates and populates an instance of this structure to pass
6786** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
6787** Additionally, an instance of this structure can be used as an
6788** output variable when querying the system for the current mutex
6789** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
6790**
6791** ^The xMutexInit method defined by this structure is invoked as
6792** part of system initialization by the sqlite3_initialize() function.
6793** ^The xMutexInit routine is called by SQLite exactly once for each
6794** effective call to [sqlite3_initialize()].
6795**
6796** ^The xMutexEnd method defined by this structure is invoked as
6797** part of system shutdown by the sqlite3_shutdown() function. The
6798** implementation of this method is expected to release all outstanding
6799** resources obtained by the mutex methods implementation, especially
6800** those obtained by the xMutexInit method. ^The xMutexEnd()
6801** interface is invoked exactly once for each call to [sqlite3_shutdown()].
6802**
6803** ^(The remaining seven methods defined by this structure (xMutexAlloc,
6804** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
6805** xMutexNotheld) implement the following interfaces (respectively):
6806**
6807** <ul>
6808** <li> [sqlite3_mutex_alloc()] </li>
6809** <li> [sqlite3_mutex_free()] </li>
6810** <li> [sqlite3_mutex_enter()] </li>
6811** <li> [sqlite3_mutex_try()] </li>
6812** <li> [sqlite3_mutex_leave()] </li>
6813** <li> [sqlite3_mutex_held()] </li>
6814** <li> [sqlite3_mutex_notheld()] </li>
6815** </ul>)^
6816**
6817** The only difference is that the public sqlite3_XXX functions enumerated
6818** above silently ignore any invocations that pass a NULL pointer instead
6819** of a valid mutex handle. The implementations of the methods defined
6820** by this structure are not required to handle this case, the results
6821** of passing a NULL pointer instead of a valid mutex handle are undefined
6822** (i.e. it is acceptable to provide an implementation that segfaults if
6823** it is passed a NULL pointer).
6824**
6825** The xMutexInit() method must be threadsafe. It must be harmless to
6826** invoke xMutexInit() multiple times within the same process and without
6827** intervening calls to xMutexEnd(). Second and subsequent calls to
6828** xMutexInit() must be no-ops.
6829**
6830** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
6831** and its associates). Similarly, xMutexAlloc() must not use SQLite memory
6832** allocation for a static mutex. ^However xMutexAlloc() may use SQLite
6833** memory allocation for a fast or recursive mutex.
6834**
6835** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
6836** called, but only if the prior call to xMutexInit returned SQLITE_OK.
6837** If xMutexInit fails in any way, it is expected to clean up after itself
6838** prior to returning.
6839*/
6840typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
6841struct sqlite3_mutex_methods {
6842 int (*xMutexInit)(void);
6843 int (*xMutexEnd)(void);
6844 sqlite3_mutex *(*xMutexAlloc)(int);
6845 void (*xMutexFree)(sqlite3_mutex *);
6846 void (*xMutexEnter)(sqlite3_mutex *);
6847 int (*xMutexTry)(sqlite3_mutex *);
6848 void (*xMutexLeave)(sqlite3_mutex *);
6849 int (*xMutexHeld)(sqlite3_mutex *);
6850 int (*xMutexNotheld)(sqlite3_mutex *);
6851};
6852
6853/*
6854** CAPI3REF: Mutex Verification Routines
6855**
6856** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
6857** are intended for use inside assert() statements. The SQLite core
6858** never uses these routines except inside an assert() and applications
6859** are advised to follow the lead of the core. The SQLite core only
6860** provides implementations for these routines when it is compiled
6861** with the SQLITE_DEBUG flag. External mutex implementations
6862** are only required to provide these routines if SQLITE_DEBUG is
6863** defined and if NDEBUG is not defined.
6864**
6865** These routines should return true if the mutex in their argument
6866** is held or not held, respectively, by the calling thread.
6867**
6868** The implementation is not required to provide versions of these
6869** routines that actually work. If the implementation does not provide working
6870** versions of these routines, it should at least provide stubs that always
6871** return true so that one does not get spurious assertion failures.
6872**
6873** If the argument to sqlite3_mutex_held() is a NULL pointer then
6874** the routine should return 1. This seems counter-intuitive since
6875** clearly the mutex cannot be held if it does not exist. But
6876** the reason the mutex does not exist is because the build is not
6877** using mutexes. And we do not want the assert() containing the
6878** call to sqlite3_mutex_held() to fail, so a non-zero return is
6879** the appropriate thing to do. The sqlite3_mutex_notheld()
6880** interface should also return 1 when given a NULL pointer.
6881*/
6882#ifndef NDEBUG
6883SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*);
6884SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);
6885#endif
6886
6887/*
6888** CAPI3REF: Mutex Types
6889**
6890** The [sqlite3_mutex_alloc()] interface takes a single argument
6891** which is one of these integer constants.
6892**
6893** The set of static mutexes may change from one SQLite release to the
6894** next. Applications that override the built-in mutex logic must be
6895** prepared to accommodate additional static mutexes.
6896*/
6897#define SQLITE_MUTEX_FAST 0
6898#define SQLITE_MUTEX_RECURSIVE 1
6899#define SQLITE_MUTEX_STATIC_MASTER 2
6900#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */
6901#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */
6902#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */
6903#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */
6904#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */
6905#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */
6906#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */
6907#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */
6908#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */
6909#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */
6910#define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */
6911#define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */
6912#define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */
6913
6914/*
6915** CAPI3REF: Retrieve the mutex for a database connection
6916** METHOD: sqlite3
6917**
6918** ^This interface returns a pointer the [sqlite3_mutex] object that
6919** serializes access to the [database connection] given in the argument
6920** when the [threading mode] is Serialized.
6921** ^If the [threading mode] is Single-thread or Multi-thread then this
6922** routine returns a NULL pointer.
6923*/
6924SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*);
6925
6926/*
6927** CAPI3REF: Low-Level Control Of Database Files
6928** METHOD: sqlite3
6929**
6930** ^The [sqlite3_file_control()] interface makes a direct call to the
6931** xFileControl method for the [sqlite3_io_methods] object associated
6932** with a particular database identified by the second argument. ^The
6933** name of the database is "main" for the main database or "temp" for the
6934** TEMP database, or the name that appears after the AS keyword for
6935** databases that are added using the [ATTACH] SQL command.
6936** ^A NULL pointer can be used in place of "main" to refer to the
6937** main database file.
6938** ^The third and fourth parameters to this routine
6939** are passed directly through to the second and third parameters of
6940** the xFileControl method. ^The return value of the xFileControl
6941** method becomes the return value of this routine.
6942**
6943** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes
6944** a pointer to the underlying [sqlite3_file] object to be written into
6945** the space pointed to by the 4th parameter. ^The [SQLITE_FCNTL_FILE_POINTER]
6946** case is a short-circuit path which does not actually invoke the
6947** underlying sqlite3_io_methods.xFileControl method.
6948**
6949** ^If the second parameter (zDbName) does not match the name of any
6950** open database file, then SQLITE_ERROR is returned. ^This error
6951** code is not remembered and will not be recalled by [sqlite3_errcode()]
6952** or [sqlite3_errmsg()]. The underlying xFileControl method might
6953** also return SQLITE_ERROR. There is no way to distinguish between
6954** an incorrect zDbName and an SQLITE_ERROR return from the underlying
6955** xFileControl method.
6956**
6957** See also: [file control opcodes]
6958*/
6959SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
6960
6961/*
6962** CAPI3REF: Testing Interface
6963**
6964** ^The sqlite3_test_control() interface is used to read out internal
6965** state of SQLite and to inject faults into SQLite for testing
6966** purposes. ^The first parameter is an operation code that determines
6967** the number, meaning, and operation of all subsequent parameters.
6968**
6969** This interface is not for use by applications. It exists solely
6970** for verifying the correct operation of the SQLite library. Depending
6971** on how the SQLite library is compiled, this interface might not exist.
6972**
6973** The details of the operation codes, their meanings, the parameters
6974** they take, and what they do are all subject to change without notice.
6975** Unlike most of the SQLite API, this function is not guaranteed to
6976** operate consistently from one release to the next.
6977*/
6978SQLITE_API int sqlite3_test_control(int op, ...);
6979
6980/*
6981** CAPI3REF: Testing Interface Operation Codes
6982**
6983** These constants are the valid operation code parameters used
6984** as the first argument to [sqlite3_test_control()].
6985**
6986** These parameters and their meanings are subject to change
6987** without notice. These values are for testing purposes only.
6988** Applications should not use any of these parameters or the
6989** [sqlite3_test_control()] interface.
6990*/
6991#define SQLITE_TESTCTRL_FIRST 5
6992#define SQLITE_TESTCTRL_PRNG_SAVE 5
6993#define SQLITE_TESTCTRL_PRNG_RESTORE 6
6994#define SQLITE_TESTCTRL_PRNG_RESET 7
6995#define SQLITE_TESTCTRL_BITVEC_TEST 8
6996#define SQLITE_TESTCTRL_FAULT_INSTALL 9
6997#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10
6998#define SQLITE_TESTCTRL_PENDING_BYTE 11
6999#define SQLITE_TESTCTRL_ASSERT 12
7000#define SQLITE_TESTCTRL_ALWAYS 13
7001#define SQLITE_TESTCTRL_RESERVE 14
7002#define SQLITE_TESTCTRL_OPTIMIZATIONS 15
7003#define SQLITE_TESTCTRL_ISKEYWORD 16
7004#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */
7005#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18
7006#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */
7007#define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19
7008#define SQLITE_TESTCTRL_NEVER_CORRUPT 20
7009#define SQLITE_TESTCTRL_VDBE_COVERAGE 21
7010#define SQLITE_TESTCTRL_BYTEORDER 22
7011#define SQLITE_TESTCTRL_ISINIT 23
7012#define SQLITE_TESTCTRL_SORTER_MMAP 24
7013#define SQLITE_TESTCTRL_IMPOSTER 25
7014#define SQLITE_TESTCTRL_PARSER_COVERAGE 26
7015#define SQLITE_TESTCTRL_LAST 26 /* Largest TESTCTRL */
7016
7017/*
7018** CAPI3REF: SQLite Runtime Status
7019**
7020** ^These interfaces are used to retrieve runtime status information
7021** about the performance of SQLite, and optionally to reset various
7022** highwater marks. ^The first argument is an integer code for
7023** the specific parameter to measure. ^(Recognized integer codes
7024** are of the form [status parameters | SQLITE_STATUS_...].)^
7025** ^The current value of the parameter is returned into *pCurrent.
7026** ^The highest recorded value is returned in *pHighwater. ^If the
7027** resetFlag is true, then the highest record value is reset after
7028** *pHighwater is written. ^(Some parameters do not record the highest
7029** value. For those parameters
7030** nothing is written into *pHighwater and the resetFlag is ignored.)^
7031** ^(Other parameters record only the highwater mark and not the current
7032** value. For these latter parameters nothing is written into *pCurrent.)^
7033**
7034** ^The sqlite3_status() and sqlite3_status64() routines return
7035** SQLITE_OK on success and a non-zero [error code] on failure.
7036**
7037** If either the current value or the highwater mark is too large to
7038** be represented by a 32-bit integer, then the values returned by
7039** sqlite3_status() are undefined.
7040**
7041** See also: [sqlite3_db_status()]
7042*/
7043SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
7044SQLITE_API int sqlite3_status64(
7045 int op,
7046 sqlite3_int64 *pCurrent,
7047 sqlite3_int64 *pHighwater,
7048 int resetFlag
7049);
7050
7051
7052/*
7053** CAPI3REF: Status Parameters
7054** KEYWORDS: {status parameters}
7055**
7056** These integer constants designate various run-time status parameters
7057** that can be returned by [sqlite3_status()].
7058**
7059** <dl>
7060** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>
7061** <dd>This parameter is the current amount of memory checked out
7062** using [sqlite3_malloc()], either directly or indirectly. The
7063** figure includes calls made to [sqlite3_malloc()] by the application
7064** and internal memory usage by the SQLite library. Auxiliary page-cache
7065** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
7066** this parameter. The amount returned is the sum of the allocation
7067** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
7068**
7069** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>
7070** <dd>This parameter records the largest memory allocation request
7071** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
7072** internal equivalents). Only the value returned in the
7073** *pHighwater parameter to [sqlite3_status()] is of interest.
7074** The value written into the *pCurrent parameter is undefined.</dd>)^
7075**
7076** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt>
7077** <dd>This parameter records the number of separate memory allocations
7078** currently checked out.</dd>)^
7079**
7080** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
7081** <dd>This parameter returns the number of pages used out of the
7082** [pagecache memory allocator] that was configured using
7083** [SQLITE_CONFIG_PAGECACHE]. The
7084** value returned is in pages, not in bytes.</dd>)^
7085**
7086** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]]
7087** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
7088** <dd>This parameter returns the number of bytes of page cache
7089** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]
7090** buffer and where forced to overflow to [sqlite3_malloc()]. The
7091** returned value includes allocations that overflowed because they
7092** where too large (they were larger than the "sz" parameter to
7093** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
7094** no space was left in the page cache.</dd>)^
7095**
7096** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
7097** <dd>This parameter records the largest memory allocation request
7098** handed to [pagecache memory allocator]. Only the value returned in the
7099** *pHighwater parameter to [sqlite3_status()] is of interest.
7100** The value written into the *pCurrent parameter is undefined.</dd>)^
7101**
7102** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt>
7103** <dd>No longer used.</dd>
7104**
7105** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
7106** <dd>No longer used.</dd>
7107**
7108** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
7109** <dd>No longer used.</dd>
7110**
7111** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
7112** <dd>The *pHighwater parameter records the deepest parser stack.
7113** The *pCurrent value is undefined. The *pHighwater value is only
7114** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
7115** </dl>
7116**
7117** New status parameters may be added from time to time.
7118*/
7119#define SQLITE_STATUS_MEMORY_USED 0
7120#define SQLITE_STATUS_PAGECACHE_USED 1
7121#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2
7122#define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */
7123#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */
7124#define SQLITE_STATUS_MALLOC_SIZE 5
7125#define SQLITE_STATUS_PARSER_STACK 6
7126#define SQLITE_STATUS_PAGECACHE_SIZE 7
7127#define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */
7128#define SQLITE_STATUS_MALLOC_COUNT 9
7129
7130/*
7131** CAPI3REF: Database Connection Status
7132** METHOD: sqlite3
7133**
7134** ^This interface is used to retrieve runtime status information
7135** about a single [database connection]. ^The first argument is the
7136** database connection object to be interrogated. ^The second argument
7137** is an integer constant, taken from the set of
7138** [SQLITE_DBSTATUS options], that
7139** determines the parameter to interrogate. The set of
7140** [SQLITE_DBSTATUS options] is likely
7141** to grow in future releases of SQLite.
7142**
7143** ^The current value of the requested parameter is written into *pCur
7144** and the highest instantaneous value is written into *pHiwtr. ^If
7145** the resetFlg is true, then the highest instantaneous value is
7146** reset back down to the current value.
7147**
7148** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
7149** non-zero [error code] on failure.
7150**
7151** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
7152*/
7153SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
7154
7155/*
7156** CAPI3REF: Status Parameters for database connections
7157** KEYWORDS: {SQLITE_DBSTATUS options}
7158**
7159** These constants are the available integer "verbs" that can be passed as
7160** the second argument to the [sqlite3_db_status()] interface.
7161**
7162** New verbs may be added in future releases of SQLite. Existing verbs
7163** might be discontinued. Applications should check the return code from
7164** [sqlite3_db_status()] to make sure that the call worked.
7165** The [sqlite3_db_status()] interface will return a non-zero error code
7166** if a discontinued or unsupported verb is invoked.
7167**
7168** <dl>
7169** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
7170** <dd>This parameter returns the number of lookaside memory slots currently
7171** checked out.</dd>)^
7172**
7173** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt>
7174** <dd>This parameter returns the number malloc attempts that were
7175** satisfied using lookaside memory. Only the high-water value is meaningful;
7176** the current value is always zero.)^
7177**
7178** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]]
7179** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt>
7180** <dd>This parameter returns the number malloc attempts that might have
7181** been satisfied using lookaside memory but failed due to the amount of
7182** memory requested being larger than the lookaside slot size.
7183** Only the high-water value is meaningful;
7184** the current value is always zero.)^
7185**
7186** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]]
7187** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt>
7188** <dd>This parameter returns the number malloc attempts that might have
7189** been satisfied using lookaside memory but failed due to all lookaside
7190** memory already being in use.
7191** Only the high-water value is meaningful;
7192** the current value is always zero.)^
7193**
7194** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
7195** <dd>This parameter returns the approximate number of bytes of heap
7196** memory used by all pager caches associated with the database connection.)^
7197** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
7198**
7199** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]]
7200** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt>
7201** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a
7202** pager cache is shared between two or more connections the bytes of heap
7203** memory used by that pager cache is divided evenly between the attached
7204** connections.)^ In other words, if none of the pager caches associated
7205** with the database connection are shared, this request returns the same
7206** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are
7207** shared, the value returned by this call will be smaller than that returned
7208** by DBSTATUS_CACHE_USED. ^The highwater mark associated with
7209** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0.
7210**
7211** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>
7212** <dd>This parameter returns the approximate number of bytes of heap
7213** memory used to store the schema for all databases associated
7214** with the connection - main, temp, and any [ATTACH]-ed databases.)^
7215** ^The full amount of memory used by the schemas is reported, even if the
7216** schema memory is shared with other database connections due to
7217** [shared cache mode] being enabled.
7218** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
7219**
7220** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt>
7221** <dd>This parameter returns the approximate number of bytes of heap
7222** and lookaside memory used by all prepared statements associated with
7223** the database connection.)^
7224** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
7225** </dd>
7226**
7227** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt>
7228** <dd>This parameter returns the number of pager cache hits that have
7229** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT
7230** is always 0.
7231** </dd>
7232**
7233** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt>
7234** <dd>This parameter returns the number of pager cache misses that have
7235** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS
7236** is always 0.
7237** </dd>
7238**
7239** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt>
7240** <dd>This parameter returns the number of dirty cache entries that have
7241** been written to disk. Specifically, the number of pages written to the
7242** wal file in wal mode databases, or the number of pages written to the
7243** database file in rollback mode databases. Any pages written as part of
7244** transaction rollback or database recovery operations are not included.
7245** If an IO or other error occurs while writing a page to disk, the effect
7246** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The
7247** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0.
7248** </dd>
7249**
7250** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt>
7251** <dd>This parameter returns the number of dirty cache entries that have
7252** been written to disk in the middle of a transaction due to the page
7253** cache overflowing. Transactions are more efficient if they are written
7254** to disk all at once. When pages spill mid-transaction, that introduces
7255** additional overhead. This parameter can be used help identify
7256** inefficiencies that can be resolve by increasing the cache size.
7257** </dd>
7258**
7259** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt>
7260** <dd>This parameter returns zero for the current value if and only if
7261** all foreign key constraints (deferred or immediate) have been
7262** resolved.)^ ^The highwater mark is always 0.
7263** </dd>
7264** </dl>
7265*/
7266#define SQLITE_DBSTATUS_LOOKASIDE_USED 0
7267#define SQLITE_DBSTATUS_CACHE_USED 1
7268#define SQLITE_DBSTATUS_SCHEMA_USED 2
7269#define SQLITE_DBSTATUS_STMT_USED 3
7270#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4
7271#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5
7272#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6
7273#define SQLITE_DBSTATUS_CACHE_HIT 7
7274#define SQLITE_DBSTATUS_CACHE_MISS 8
7275#define SQLITE_DBSTATUS_CACHE_WRITE 9
7276#define SQLITE_DBSTATUS_DEFERRED_FKS 10
7277#define SQLITE_DBSTATUS_CACHE_USED_SHARED 11
7278#define SQLITE_DBSTATUS_CACHE_SPILL 12
7279#define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */
7280
7281
7282/*
7283** CAPI3REF: Prepared Statement Status
7284** METHOD: sqlite3_stmt
7285**
7286** ^(Each prepared statement maintains various
7287** [SQLITE_STMTSTATUS counters] that measure the number
7288** of times it has performed specific operations.)^ These counters can
7289** be used to monitor the performance characteristics of the prepared
7290** statements. For example, if the number of table steps greatly exceeds
7291** the number of table searches or result rows, that would tend to indicate
7292** that the prepared statement is using a full table scan rather than
7293** an index.
7294**
7295** ^(This interface is used to retrieve and reset counter values from
7296** a [prepared statement]. The first argument is the prepared statement
7297** object to be interrogated. The second argument
7298** is an integer code for a specific [SQLITE_STMTSTATUS counter]
7299** to be interrogated.)^
7300** ^The current value of the requested counter is returned.
7301** ^If the resetFlg is true, then the counter is reset to zero after this
7302** interface call returns.
7303**
7304** See also: [sqlite3_status()] and [sqlite3_db_status()].
7305*/
7306SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
7307
7308/*
7309** CAPI3REF: Status Parameters for prepared statements
7310** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters}
7311**
7312** These preprocessor macros define integer codes that name counter
7313** values associated with the [sqlite3_stmt_status()] interface.
7314** The meanings of the various counters are as follows:
7315**
7316** <dl>
7317** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
7318** <dd>^This is the number of times that SQLite has stepped forward in
7319** a table as part of a full table scan. Large numbers for this counter
7320** may indicate opportunities for performance improvement through
7321** careful use of indices.</dd>
7322**
7323** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt>
7324** <dd>^This is the number of sort operations that have occurred.
7325** A non-zero value in this counter may indicate an opportunity to
7326** improvement performance through careful use of indices.</dd>
7327**
7328** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt>
7329** <dd>^This is the number of rows inserted into transient indices that
7330** were created automatically in order to help joins run faster.
7331** A non-zero value in this counter may indicate an opportunity to
7332** improvement performance by adding permanent indices that do not
7333** need to be reinitialized each time the statement is run.</dd>
7334**
7335** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt>
7336** <dd>^This is the number of virtual machine operations executed
7337** by the prepared statement if that number is less than or equal
7338** to 2147483647. The number of virtual machine operations can be
7339** used as a proxy for the total work done by the prepared statement.
7340** If the number of virtual machine operations exceeds 2147483647
7341** then the value returned by this statement status code is undefined.
7342**
7343** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt>
7344** <dd>^This is the number of times that the prepare statement has been
7345** automatically regenerated due to schema changes or change to
7346** [bound parameters] that might affect the query plan.
7347**
7348** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt>
7349** <dd>^This is the number of times that the prepared statement has
7350** been run. A single "run" for the purposes of this counter is one
7351** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()].
7352** The counter is incremented on the first [sqlite3_step()] call of each
7353** cycle.
7354**
7355** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt>
7356** <dd>^This is the approximate number of bytes of heap memory
7357** used to store the prepared statement. ^This value is not actually
7358** a counter, and so the resetFlg parameter to sqlite3_stmt_status()
7359** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED.
7360** </dd>
7361** </dl>
7362*/
7363#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1
7364#define SQLITE_STMTSTATUS_SORT 2
7365#define SQLITE_STMTSTATUS_AUTOINDEX 3
7366#define SQLITE_STMTSTATUS_VM_STEP 4
7367#define SQLITE_STMTSTATUS_REPREPARE 5
7368#define SQLITE_STMTSTATUS_RUN 6
7369#define SQLITE_STMTSTATUS_MEMUSED 99
7370
7371/*
7372** CAPI3REF: Custom Page Cache Object
7373**
7374** The sqlite3_pcache type is opaque. It is implemented by
7375** the pluggable module. The SQLite core has no knowledge of
7376** its size or internal structure and never deals with the
7377** sqlite3_pcache object except by holding and passing pointers
7378** to the object.
7379**
7380** See [sqlite3_pcache_methods2] for additional information.
7381*/
7382typedef struct sqlite3_pcache sqlite3_pcache;
7383
7384/*
7385** CAPI3REF: Custom Page Cache Object
7386**
7387** The sqlite3_pcache_page object represents a single page in the
7388** page cache. The page cache will allocate instances of this
7389** object. Various methods of the page cache use pointers to instances
7390** of this object as parameters or as their return value.
7391**
7392** See [sqlite3_pcache_methods2] for additional information.
7393*/
7394typedef struct sqlite3_pcache_page sqlite3_pcache_page;
7395struct sqlite3_pcache_page {
7396 void *pBuf; /* The content of the page */
7397 void *pExtra; /* Extra information associated with the page */
7398};
7399
7400/*
7401** CAPI3REF: Application Defined Page Cache.
7402** KEYWORDS: {page cache}
7403**
7404** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can
7405** register an alternative page cache implementation by passing in an
7406** instance of the sqlite3_pcache_methods2 structure.)^
7407** In many applications, most of the heap memory allocated by
7408** SQLite is used for the page cache.
7409** By implementing a
7410** custom page cache using this API, an application can better control
7411** the amount of memory consumed by SQLite, the way in which
7412** that memory is allocated and released, and the policies used to
7413** determine exactly which parts of a database file are cached and for
7414** how long.
7415**
7416** The alternative page cache mechanism is an
7417** extreme measure that is only needed by the most demanding applications.
7418** The built-in page cache is recommended for most uses.
7419**
7420** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an
7421** internal buffer by SQLite within the call to [sqlite3_config]. Hence
7422** the application may discard the parameter after the call to
7423** [sqlite3_config()] returns.)^
7424**
7425** [[the xInit() page cache method]]
7426** ^(The xInit() method is called once for each effective
7427** call to [sqlite3_initialize()])^
7428** (usually only once during the lifetime of the process). ^(The xInit()
7429** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^
7430** The intent of the xInit() method is to set up global data structures
7431** required by the custom page cache implementation.
7432** ^(If the xInit() method is NULL, then the
7433** built-in default page cache is used instead of the application defined
7434** page cache.)^
7435**
7436** [[the xShutdown() page cache method]]
7437** ^The xShutdown() method is called by [sqlite3_shutdown()].
7438** It can be used to clean up
7439** any outstanding resources before process shutdown, if required.
7440** ^The xShutdown() method may be NULL.
7441**
7442** ^SQLite automatically serializes calls to the xInit method,
7443** so the xInit method need not be threadsafe. ^The
7444** xShutdown method is only called from [sqlite3_shutdown()] so it does
7445** not need to be threadsafe either. All other methods must be threadsafe
7446** in multithreaded applications.
7447**
7448** ^SQLite will never invoke xInit() more than once without an intervening
7449** call to xShutdown().
7450**
7451** [[the xCreate() page cache methods]]
7452** ^SQLite invokes the xCreate() method to construct a new cache instance.
7453** SQLite will typically create one cache instance for each open database file,
7454** though this is not guaranteed. ^The
7455** first parameter, szPage, is the size in bytes of the pages that must
7456** be allocated by the cache. ^szPage will always a power of two. ^The
7457** second parameter szExtra is a number of bytes of extra storage
7458** associated with each page cache entry. ^The szExtra parameter will
7459** a number less than 250. SQLite will use the
7460** extra szExtra bytes on each page to store metadata about the underlying
7461** database page on disk. The value passed into szExtra depends
7462** on the SQLite version, the target platform, and how SQLite was compiled.
7463** ^The third argument to xCreate(), bPurgeable, is true if the cache being
7464** created will be used to cache database pages of a file stored on disk, or
7465** false if it is used for an in-memory database. The cache implementation
7466** does not have to do anything special based with the value of bPurgeable;
7467** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will
7468** never invoke xUnpin() except to deliberately delete a page.
7469** ^In other words, calls to xUnpin() on a cache with bPurgeable set to
7470** false will always have the "discard" flag set to true.
7471** ^Hence, a cache created with bPurgeable false will
7472** never contain any unpinned pages.
7473**
7474** [[the xCachesize() page cache method]]
7475** ^(The xCachesize() method may be called at any time by SQLite to set the
7476** suggested maximum cache-size (number of pages stored by) the cache
7477** instance passed as the first argument. This is the value configured using
7478** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable
7479** parameter, the implementation is not required to do anything with this
7480** value; it is advisory only.
7481**
7482** [[the xPagecount() page cache methods]]
7483** The xPagecount() method must return the number of pages currently
7484** stored in the cache, both pinned and unpinned.
7485**
7486** [[the xFetch() page cache methods]]
7487** The xFetch() method locates a page in the cache and returns a pointer to
7488** an sqlite3_pcache_page object associated with that page, or a NULL pointer.
7489** The pBuf element of the returned sqlite3_pcache_page object will be a
7490** pointer to a buffer of szPage bytes used to store the content of a
7491** single database page. The pExtra element of sqlite3_pcache_page will be
7492** a pointer to the szExtra bytes of extra storage that SQLite has requested
7493** for each entry in the page cache.
7494**
7495** The page to be fetched is determined by the key. ^The minimum key value
7496** is 1. After it has been retrieved using xFetch, the page is considered
7497** to be "pinned".
7498**
7499** If the requested page is already in the page cache, then the page cache
7500** implementation must return a pointer to the page buffer with its content
7501** intact. If the requested page is not already in the cache, then the
7502** cache implementation should use the value of the createFlag
7503** parameter to help it determined what action to take:
7504**
7505** <table border=1 width=85% align=center>
7506** <tr><th> createFlag <th> Behavior when page is not already in cache
7507** <tr><td> 0 <td> Do not allocate a new page. Return NULL.
7508** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so.
7509** Otherwise return NULL.
7510** <tr><td> 2 <td> Make every effort to allocate a new page. Only return
7511** NULL if allocating a new page is effectively impossible.
7512** </table>
7513**
7514** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite
7515** will only use a createFlag of 2 after a prior call with a createFlag of 1
7516** failed.)^ In between the to xFetch() calls, SQLite may
7517** attempt to unpin one or more cache pages by spilling the content of
7518** pinned pages to disk and synching the operating system disk cache.
7519**
7520** [[the xUnpin() page cache method]]
7521** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
7522** as its second argument. If the third parameter, discard, is non-zero,
7523** then the page must be evicted from the cache.
7524** ^If the discard parameter is
7525** zero, then the page may be discarded or retained at the discretion of
7526** page cache implementation. ^The page cache implementation
7527** may choose to evict unpinned pages at any time.
7528**
7529** The cache must not perform any reference counting. A single
7530** call to xUnpin() unpins the page regardless of the number of prior calls
7531** to xFetch().
7532**
7533** [[the xRekey() page cache methods]]
7534** The xRekey() method is used to change the key value associated with the
7535** page passed as the second argument. If the cache
7536** previously contains an entry associated with newKey, it must be
7537** discarded. ^Any prior cache entry associated with newKey is guaranteed not
7538** to be pinned.
7539**
7540** When SQLite calls the xTruncate() method, the cache must discard all
7541** existing cache entries with page numbers (keys) greater than or equal
7542** to the value of the iLimit parameter passed to xTruncate(). If any
7543** of these pages are pinned, they are implicitly unpinned, meaning that
7544** they can be safely discarded.
7545**
7546** [[the xDestroy() page cache method]]
7547** ^The xDestroy() method is used to delete a cache allocated by xCreate().
7548** All resources associated with the specified cache should be freed. ^After
7549** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
7550** handle invalid, and will not use it with any other sqlite3_pcache_methods2
7551** functions.
7552**
7553** [[the xShrink() page cache method]]
7554** ^SQLite invokes the xShrink() method when it wants the page cache to
7555** free up as much of heap memory as possible. The page cache implementation
7556** is not obligated to free any memory, but well-behaved implementations should
7557** do their best.
7558*/
7559typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2;
7560struct sqlite3_pcache_methods2 {
7561 int iVersion;
7562 void *pArg;
7563 int (*xInit)(void*);
7564 void (*xShutdown)(void*);
7565 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable);
7566 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
7567 int (*xPagecount)(sqlite3_pcache*);
7568 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
7569 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard);
7570 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*,
7571 unsigned oldKey, unsigned newKey);
7572 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
7573 void (*xDestroy)(sqlite3_pcache*);
7574 void (*xShrink)(sqlite3_pcache*);
7575};
7576
7577/*
7578** This is the obsolete pcache_methods object that has now been replaced
7579** by sqlite3_pcache_methods2. This object is not used by SQLite. It is
7580** retained in the header file for backwards compatibility only.
7581*/
7582typedef struct sqlite3_pcache_methods sqlite3_pcache_methods;
7583struct sqlite3_pcache_methods {
7584 void *pArg;
7585 int (*xInit)(void*);
7586 void (*xShutdown)(void*);
7587 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable);
7588 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
7589 int (*xPagecount)(sqlite3_pcache*);
7590 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
7591 void (*xUnpin)(sqlite3_pcache*, void*, int discard);
7592 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey);
7593 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
7594 void (*xDestroy)(sqlite3_pcache*);
7595};
7596
7597
7598/*
7599** CAPI3REF: Online Backup Object
7600**
7601** The sqlite3_backup object records state information about an ongoing
7602** online backup operation. ^The sqlite3_backup object is created by
7603** a call to [sqlite3_backup_init()] and is destroyed by a call to
7604** [sqlite3_backup_finish()].
7605**
7606** See Also: [Using the SQLite Online Backup API]
7607*/
7608typedef struct sqlite3_backup sqlite3_backup;
7609
7610/*
7611** CAPI3REF: Online Backup API.
7612**
7613** The backup API copies the content of one database into another.
7614** It is useful either for creating backups of databases or
7615** for copying in-memory databases to or from persistent files.
7616**
7617** See Also: [Using the SQLite Online Backup API]
7618**
7619** ^SQLite holds a write transaction open on the destination database file
7620** for the duration of the backup operation.
7621** ^The source database is read-locked only while it is being read;
7622** it is not locked continuously for the entire backup operation.
7623** ^Thus, the backup may be performed on a live source database without
7624** preventing other database connections from
7625** reading or writing to the source database while the backup is underway.
7626**
7627** ^(To perform a backup operation:
7628** <ol>
7629** <li><b>sqlite3_backup_init()</b> is called once to initialize the
7630** backup,
7631** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer
7632** the data between the two databases, and finally
7633** <li><b>sqlite3_backup_finish()</b> is called to release all resources
7634** associated with the backup operation.
7635** </ol>)^
7636** There should be exactly one call to sqlite3_backup_finish() for each
7637** successful call to sqlite3_backup_init().
7638**
7639** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b>
7640**
7641** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the
7642** [database connection] associated with the destination database
7643** and the database name, respectively.
7644** ^The database name is "main" for the main database, "temp" for the
7645** temporary database, or the name specified after the AS keyword in
7646** an [ATTACH] statement for an attached database.
7647** ^The S and M arguments passed to
7648** sqlite3_backup_init(D,N,S,M) identify the [database connection]
7649** and database name of the source database, respectively.
7650** ^The source and destination [database connections] (parameters S and D)
7651** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
7652** an error.
7653**
7654** ^A call to sqlite3_backup_init() will fail, returning NULL, if
7655** there is already a read or read-write transaction open on the
7656** destination database.
7657**
7658** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
7659** returned and an error code and error message are stored in the
7660** destination [database connection] D.
7661** ^The error code and message for the failed call to sqlite3_backup_init()
7662** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
7663** [sqlite3_errmsg16()] functions.
7664** ^A successful call to sqlite3_backup_init() returns a pointer to an
7665** [sqlite3_backup] object.
7666** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
7667** sqlite3_backup_finish() functions to perform the specified backup
7668** operation.
7669**
7670** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b>
7671**
7672** ^Function sqlite3_backup_step(B,N) will copy up to N pages between
7673** the source and destination databases specified by [sqlite3_backup] object B.
7674** ^If N is negative, all remaining source pages are copied.
7675** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
7676** are still more pages to be copied, then the function returns [SQLITE_OK].
7677** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
7678** from source to destination, then it returns [SQLITE_DONE].
7679** ^If an error occurs while running sqlite3_backup_step(B,N),
7680** then an [error code] is returned. ^As well as [SQLITE_OK] and
7681** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
7682** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
7683** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
7684**
7685** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if
7686** <ol>
7687** <li> the destination database was opened read-only, or
7688** <li> the destination database is using write-ahead-log journaling
7689** and the destination and source page sizes differ, or
7690** <li> the destination database is an in-memory database and the
7691** destination and source page sizes differ.
7692** </ol>)^
7693**
7694** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
7695** the [sqlite3_busy_handler | busy-handler function]
7696** is invoked (if one is specified). ^If the
7697** busy-handler returns non-zero before the lock is available, then
7698** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
7699** sqlite3_backup_step() can be retried later. ^If the source
7700** [database connection]
7701** is being used to write to the source database when sqlite3_backup_step()
7702** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
7703** case the call to sqlite3_backup_step() can be retried later on. ^(If
7704** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or
7705** [SQLITE_READONLY] is returned, then
7706** there is no point in retrying the call to sqlite3_backup_step(). These
7707** errors are considered fatal.)^ The application must accept
7708** that the backup operation has failed and pass the backup operation handle
7709** to the sqlite3_backup_finish() to release associated resources.
7710**
7711** ^The first call to sqlite3_backup_step() obtains an exclusive lock
7712** on the destination file. ^The exclusive lock is not released until either
7713** sqlite3_backup_finish() is called or the backup operation is complete
7714** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to
7715** sqlite3_backup_step() obtains a [shared lock] on the source database that
7716** lasts for the duration of the sqlite3_backup_step() call.
7717** ^Because the source database is not locked between calls to
7718** sqlite3_backup_step(), the source database may be modified mid-way
7719** through the backup process. ^If the source database is modified by an
7720** external process or via a database connection other than the one being
7721** used by the backup operation, then the backup will be automatically
7722** restarted by the next call to sqlite3_backup_step(). ^If the source
7723** database is modified by the using the same database connection as is used
7724** by the backup operation, then the backup database is automatically
7725** updated at the same time.
7726**
7727** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b>
7728**
7729** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the
7730** application wishes to abandon the backup operation, the application
7731** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
7732** ^The sqlite3_backup_finish() interfaces releases all
7733** resources associated with the [sqlite3_backup] object.
7734** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
7735** active write-transaction on the destination database is rolled back.
7736** The [sqlite3_backup] object is invalid
7737** and may not be used following a call to sqlite3_backup_finish().
7738**
7739** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
7740** sqlite3_backup_step() errors occurred, regardless or whether or not
7741** sqlite3_backup_step() completed.
7742** ^If an out-of-memory condition or IO error occurred during any prior
7743** sqlite3_backup_step() call on the same [sqlite3_backup] object, then
7744** sqlite3_backup_finish() returns the corresponding [error code].
7745**
7746** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
7747** is not a permanent error and does not affect the return value of
7748** sqlite3_backup_finish().
7749**
7750** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]]
7751** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>
7752**
7753** ^The sqlite3_backup_remaining() routine returns the number of pages still
7754** to be backed up at the conclusion of the most recent sqlite3_backup_step().
7755** ^The sqlite3_backup_pagecount() routine returns the total number of pages
7756** in the source database at the conclusion of the most recent
7757** sqlite3_backup_step().
7758** ^(The values returned by these functions are only updated by
7759** sqlite3_backup_step(). If the source database is modified in a way that
7760** changes the size of the source database or the number of pages remaining,
7761** those changes are not reflected in the output of sqlite3_backup_pagecount()
7762** and sqlite3_backup_remaining() until after the next
7763** sqlite3_backup_step().)^
7764**
7765** <b>Concurrent Usage of Database Handles</b>
7766**
7767** ^The source [database connection] may be used by the application for other
7768** purposes while a backup operation is underway or being initialized.
7769** ^If SQLite is compiled and configured to support threadsafe database
7770** connections, then the source database connection may be used concurrently
7771** from within other threads.
7772**
7773** However, the application must guarantee that the destination
7774** [database connection] is not passed to any other API (by any thread) after
7775** sqlite3_backup_init() is called and before the corresponding call to
7776** sqlite3_backup_finish(). SQLite does not currently check to see
7777** if the application incorrectly accesses the destination [database connection]
7778** and so no error code is reported, but the operations may malfunction
7779** nevertheless. Use of the destination database connection while a
7780** backup is in progress might also also cause a mutex deadlock.
7781**
7782** If running in [shared cache mode], the application must
7783** guarantee that the shared cache used by the destination database
7784** is not accessed while the backup is running. In practice this means
7785** that the application must guarantee that the disk file being
7786** backed up to is not accessed by any connection within the process,
7787** not just the specific connection that was passed to sqlite3_backup_init().
7788**
7789** The [sqlite3_backup] object itself is partially threadsafe. Multiple
7790** threads may safely make multiple concurrent calls to sqlite3_backup_step().
7791** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
7792** APIs are not strictly speaking threadsafe. If they are invoked at the
7793** same time as another thread is invoking sqlite3_backup_step() it is
7794** possible that they return invalid values.
7795*/
7796SQLITE_API sqlite3_backup *sqlite3_backup_init(
7797 sqlite3 *pDest, /* Destination database handle */
7798 const char *zDestName, /* Destination database name */
7799 sqlite3 *pSource, /* Source database handle */
7800 const char *zSourceName /* Source database name */
7801);
7802SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage);
7803SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p);
7804SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p);
7805SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p);
7806
7807/*
7808** CAPI3REF: Unlock Notification
7809** METHOD: sqlite3
7810**
7811** ^When running in shared-cache mode, a database operation may fail with
7812** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
7813** individual tables within the shared-cache cannot be obtained. See
7814** [SQLite Shared-Cache Mode] for a description of shared-cache locking.
7815** ^This API may be used to register a callback that SQLite will invoke
7816** when the connection currently holding the required lock relinquishes it.
7817** ^This API is only available if the library was compiled with the
7818** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
7819**
7820** See Also: [Using the SQLite Unlock Notification Feature].
7821**
7822** ^Shared-cache locks are released when a database connection concludes
7823** its current transaction, either by committing it or rolling it back.
7824**
7825** ^When a connection (known as the blocked connection) fails to obtain a
7826** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
7827** identity of the database connection (the blocking connection) that
7828** has locked the required resource is stored internally. ^After an
7829** application receives an SQLITE_LOCKED error, it may call the
7830** sqlite3_unlock_notify() method with the blocked connection handle as
7831** the first argument to register for a callback that will be invoked
7832** when the blocking connections current transaction is concluded. ^The
7833** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
7834** call that concludes the blocking connections transaction.
7835**
7836** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
7837** there is a chance that the blocking connection will have already
7838** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
7839** If this happens, then the specified callback is invoked immediately,
7840** from within the call to sqlite3_unlock_notify().)^
7841**
7842** ^If the blocked connection is attempting to obtain a write-lock on a
7843** shared-cache table, and more than one other connection currently holds
7844** a read-lock on the same table, then SQLite arbitrarily selects one of
7845** the other connections to use as the blocking connection.
7846**
7847** ^(There may be at most one unlock-notify callback registered by a
7848** blocked connection. If sqlite3_unlock_notify() is called when the
7849** blocked connection already has a registered unlock-notify callback,
7850** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
7851** called with a NULL pointer as its second argument, then any existing
7852** unlock-notify callback is canceled. ^The blocked connections
7853** unlock-notify callback may also be canceled by closing the blocked
7854** connection using [sqlite3_close()].
7855**
7856** The unlock-notify callback is not reentrant. If an application invokes
7857** any sqlite3_xxx API functions from within an unlock-notify callback, a
7858** crash or deadlock may be the result.
7859**
7860** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
7861** returns SQLITE_OK.
7862**
7863** <b>Callback Invocation Details</b>
7864**
7865** When an unlock-notify callback is registered, the application provides a
7866** single void* pointer that is passed to the callback when it is invoked.
7867** However, the signature of the callback function allows SQLite to pass
7868** it an array of void* context pointers. The first argument passed to
7869** an unlock-notify callback is a pointer to an array of void* pointers,
7870** and the second is the number of entries in the array.
7871**
7872** When a blocking connections transaction is concluded, there may be
7873** more than one blocked connection that has registered for an unlock-notify
7874** callback. ^If two or more such blocked connections have specified the
7875** same callback function, then instead of invoking the callback function
7876** multiple times, it is invoked once with the set of void* context pointers
7877** specified by the blocked connections bundled together into an array.
7878** This gives the application an opportunity to prioritize any actions
7879** related to the set of unblocked database connections.
7880**
7881** <b>Deadlock Detection</b>
7882**
7883** Assuming that after registering for an unlock-notify callback a
7884** database waits for the callback to be issued before taking any further
7885** action (a reasonable assumption), then using this API may cause the
7886** application to deadlock. For example, if connection X is waiting for
7887** connection Y's transaction to be concluded, and similarly connection
7888** Y is waiting on connection X's transaction, then neither connection
7889** will proceed and the system may remain deadlocked indefinitely.
7890**
7891** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
7892** detection. ^If a given call to sqlite3_unlock_notify() would put the
7893** system in a deadlocked state, then SQLITE_LOCKED is returned and no
7894** unlock-notify callback is registered. The system is said to be in
7895** a deadlocked state if connection A has registered for an unlock-notify
7896** callback on the conclusion of connection B's transaction, and connection
7897** B has itself registered for an unlock-notify callback when connection
7898** A's transaction is concluded. ^Indirect deadlock is also detected, so
7899** the system is also considered to be deadlocked if connection B has
7900** registered for an unlock-notify callback on the conclusion of connection
7901** C's transaction, where connection C is waiting on connection A. ^Any
7902** number of levels of indirection are allowed.
7903**
7904** <b>The "DROP TABLE" Exception</b>
7905**
7906** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost
7907** always appropriate to call sqlite3_unlock_notify(). There is however,
7908** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
7909** SQLite checks if there are any currently executing SELECT statements
7910** that belong to the same connection. If there are, SQLITE_LOCKED is
7911** returned. In this case there is no "blocking connection", so invoking
7912** sqlite3_unlock_notify() results in the unlock-notify callback being
7913** invoked immediately. If the application then re-attempts the "DROP TABLE"
7914** or "DROP INDEX" query, an infinite loop might be the result.
7915**
7916** One way around this problem is to check the extended error code returned
7917** by an sqlite3_step() call. ^(If there is a blocking connection, then the
7918** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
7919** the special "DROP TABLE/INDEX" case, the extended error code is just
7920** SQLITE_LOCKED.)^
7921*/
7922SQLITE_API int sqlite3_unlock_notify(
7923 sqlite3 *pBlocked, /* Waiting connection */
7924 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */
7925 void *pNotifyArg /* Argument to pass to xNotify */
7926);
7927
7928
7929/*
7930** CAPI3REF: String Comparison
7931**
7932** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications
7933** and extensions to compare the contents of two buffers containing UTF-8
7934** strings in a case-independent fashion, using the same definition of "case
7935** independence" that SQLite uses internally when comparing identifiers.
7936*/
7937SQLITE_API int sqlite3_stricmp(const char *, const char *);
7938SQLITE_API int sqlite3_strnicmp(const char *, const char *, int);
7939
7940/*
7941** CAPI3REF: String Globbing
7942*
7943** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if
7944** string X matches the [GLOB] pattern P.
7945** ^The definition of [GLOB] pattern matching used in
7946** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the
7947** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function
7948** is case sensitive.
7949**
7950** Note that this routine returns zero on a match and non-zero if the strings
7951** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
7952**
7953** See also: [sqlite3_strlike()].
7954*/
7955SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr);
7956
7957/*
7958** CAPI3REF: String LIKE Matching
7959*
7960** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if
7961** string X matches the [LIKE] pattern P with escape character E.
7962** ^The definition of [LIKE] pattern matching used in
7963** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E"
7964** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without
7965** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0.
7966** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case
7967** insensitive - equivalent upper and lower case ASCII characters match
7968** one another.
7969**
7970** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though
7971** only ASCII characters are case folded.
7972**
7973** Note that this routine returns zero on a match and non-zero if the strings
7974** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
7975**
7976** See also: [sqlite3_strglob()].
7977*/
7978SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc);
7979
7980/*
7981** CAPI3REF: Error Logging Interface
7982**
7983** ^The [sqlite3_log()] interface writes a message into the [error log]
7984** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
7985** ^If logging is enabled, the zFormat string and subsequent arguments are
7986** used with [sqlite3_snprintf()] to generate the final output string.
7987**
7988** The sqlite3_log() interface is intended for use by extensions such as
7989** virtual tables, collating functions, and SQL functions. While there is
7990** nothing to prevent an application from calling sqlite3_log(), doing so
7991** is considered bad form.
7992**
7993** The zFormat string must not be NULL.
7994**
7995** To avoid deadlocks and other threading problems, the sqlite3_log() routine
7996** will not use dynamically allocated memory. The log message is stored in
7997** a fixed-length buffer on the stack. If the log message is longer than
7998** a few hundred characters, it will be truncated to the length of the
7999** buffer.
8000*/
8001SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...);
8002
8003/*
8004** CAPI3REF: Write-Ahead Log Commit Hook
8005** METHOD: sqlite3
8006**
8007** ^The [sqlite3_wal_hook()] function is used to register a callback that
8008** is invoked each time data is committed to a database in wal mode.
8009**
8010** ^(The callback is invoked by SQLite after the commit has taken place and
8011** the associated write-lock on the database released)^, so the implementation
8012** may read, write or [checkpoint] the database as required.
8013**
8014** ^The first parameter passed to the callback function when it is invoked
8015** is a copy of the third parameter passed to sqlite3_wal_hook() when
8016** registering the callback. ^The second is a copy of the database handle.
8017** ^The third parameter is the name of the database that was written to -
8018** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter
8019** is the number of pages currently in the write-ahead log file,
8020** including those that were just committed.
8021**
8022** The callback function should normally return [SQLITE_OK]. ^If an error
8023** code is returned, that error will propagate back up through the
8024** SQLite code base to cause the statement that provoked the callback
8025** to report an error, though the commit will have still occurred. If the
8026** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value
8027** that does not correspond to any valid SQLite error code, the results
8028** are undefined.
8029**
8030** A single database handle may have at most a single write-ahead log callback
8031** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any
8032** previously registered write-ahead log callback. ^Note that the
8033** [sqlite3_wal_autocheckpoint()] interface and the
8034** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will
8035** overwrite any prior [sqlite3_wal_hook()] settings.
8036*/
8037SQLITE_API void *sqlite3_wal_hook(
8038 sqlite3*,
8039 int(*)(void *,sqlite3*,const char*,int),
8040 void*
8041);
8042
8043/*
8044** CAPI3REF: Configure an auto-checkpoint
8045** METHOD: sqlite3
8046**
8047** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
8048** [sqlite3_wal_hook()] that causes any database on [database connection] D
8049** to automatically [checkpoint]
8050** after committing a transaction if there are N or
8051** more frames in the [write-ahead log] file. ^Passing zero or
8052** a negative value as the nFrame parameter disables automatic
8053** checkpoints entirely.
8054**
8055** ^The callback registered by this function replaces any existing callback
8056** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback
8057** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism
8058** configured by this function.
8059**
8060** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
8061** from SQL.
8062**
8063** ^Checkpoints initiated by this mechanism are
8064** [sqlite3_wal_checkpoint_v2|PASSIVE].
8065**
8066** ^Every new [database connection] defaults to having the auto-checkpoint
8067** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
8068** pages. The use of this interface
8069** is only necessary if the default setting is found to be suboptimal
8070** for a particular application.
8071*/
8072SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N);
8073
8074/*
8075** CAPI3REF: Checkpoint a database
8076** METHOD: sqlite3
8077**
8078** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to
8079** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^
8080**
8081** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the
8082** [write-ahead log] for database X on [database connection] D to be
8083** transferred into the database file and for the write-ahead log to
8084** be reset. See the [checkpointing] documentation for addition
8085** information.
8086**
8087** This interface used to be the only way to cause a checkpoint to
8088** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()]
8089** interface was added. This interface is retained for backwards
8090** compatibility and as a convenience for applications that need to manually
8091** start a callback but which do not need the full power (and corresponding
8092** complication) of [sqlite3_wal_checkpoint_v2()].
8093*/
8094SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);
8095
8096/*
8097** CAPI3REF: Checkpoint a database
8098** METHOD: sqlite3
8099**
8100** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint
8101** operation on database X of [database connection] D in mode M. Status
8102** information is written back into integers pointed to by L and C.)^
8103** ^(The M parameter must be a valid [checkpoint mode]:)^
8104**
8105** <dl>
8106** <dt>SQLITE_CHECKPOINT_PASSIVE<dd>
8107** ^Checkpoint as many frames as possible without waiting for any database
8108** readers or writers to finish, then sync the database file if all frames
8109** in the log were checkpointed. ^The [busy-handler callback]
8110** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode.
8111** ^On the other hand, passive mode might leave the checkpoint unfinished
8112** if there are concurrent readers or writers.
8113**
8114** <dt>SQLITE_CHECKPOINT_FULL<dd>
8115** ^This mode blocks (it invokes the
8116** [sqlite3_busy_handler|busy-handler callback]) until there is no
8117** database writer and all readers are reading from the most recent database
8118** snapshot. ^It then checkpoints all frames in the log file and syncs the
8119** database file. ^This mode blocks new database writers while it is pending,
8120** but new database readers are allowed to continue unimpeded.
8121**
8122** <dt>SQLITE_CHECKPOINT_RESTART<dd>
8123** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition
8124** that after checkpointing the log file it blocks (calls the
8125** [busy-handler callback])
8126** until all readers are reading from the database file only. ^This ensures
8127** that the next writer will restart the log file from the beginning.
8128** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new
8129** database writer attempts while it is pending, but does not impede readers.
8130**
8131** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd>
8132** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the
8133** addition that it also truncates the log file to zero bytes just prior
8134** to a successful return.
8135** </dl>
8136**
8137** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in
8138** the log file or to -1 if the checkpoint could not run because
8139** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not
8140** NULL,then *pnCkpt is set to the total number of checkpointed frames in the
8141** log file (including any that were already checkpointed before the function
8142** was called) or to -1 if the checkpoint could not run due to an error or
8143** because the database is not in WAL mode. ^Note that upon successful
8144** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been
8145** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero.
8146**
8147** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If
8148** any other process is running a checkpoint operation at the same time, the
8149** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a
8150** busy-handler configured, it will not be invoked in this case.
8151**
8152** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the
8153** exclusive "writer" lock on the database file. ^If the writer lock cannot be
8154** obtained immediately, and a busy-handler is configured, it is invoked and
8155** the writer lock retried until either the busy-handler returns 0 or the lock
8156** is successfully obtained. ^The busy-handler is also invoked while waiting for
8157** database readers as described above. ^If the busy-handler returns 0 before
8158** the writer lock is obtained or while waiting for database readers, the
8159** checkpoint operation proceeds from that point in the same way as
8160** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible
8161** without blocking any further. ^SQLITE_BUSY is returned in this case.
8162**
8163** ^If parameter zDb is NULL or points to a zero length string, then the
8164** specified operation is attempted on all WAL databases [attached] to
8165** [database connection] db. In this case the
8166** values written to output parameters *pnLog and *pnCkpt are undefined. ^If
8167** an SQLITE_BUSY error is encountered when processing one or more of the
8168** attached WAL databases, the operation is still attempted on any remaining
8169** attached databases and SQLITE_BUSY is returned at the end. ^If any other
8170** error occurs while processing an attached database, processing is abandoned
8171** and the error code is returned to the caller immediately. ^If no error
8172** (SQLITE_BUSY or otherwise) is encountered while processing the attached
8173** databases, SQLITE_OK is returned.
8174**
8175** ^If database zDb is the name of an attached database that is not in WAL
8176** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If
8177** zDb is not NULL (or a zero length string) and is not the name of any
8178** attached database, SQLITE_ERROR is returned to the caller.
8179**
8180** ^Unless it returns SQLITE_MISUSE,
8181** the sqlite3_wal_checkpoint_v2() interface
8182** sets the error information that is queried by
8183** [sqlite3_errcode()] and [sqlite3_errmsg()].
8184**
8185** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface
8186** from SQL.
8187*/
8188SQLITE_API int sqlite3_wal_checkpoint_v2(
8189 sqlite3 *db, /* Database handle */
8190 const char *zDb, /* Name of attached database (or NULL) */
8191 int eMode, /* SQLITE_CHECKPOINT_* value */
8192 int *pnLog, /* OUT: Size of WAL log in frames */
8193 int *pnCkpt /* OUT: Total number of frames checkpointed */
8194);
8195
8196/*
8197** CAPI3REF: Checkpoint Mode Values
8198** KEYWORDS: {checkpoint mode}
8199**
8200** These constants define all valid values for the "checkpoint mode" passed
8201** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface.
8202** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the
8203** meaning of each of these checkpoint modes.
8204*/
8205#define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */
8206#define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */
8207#define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */
8208#define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */
8209
8210/*
8211** CAPI3REF: Virtual Table Interface Configuration
8212**
8213** This function may be called by either the [xConnect] or [xCreate] method
8214** of a [virtual table] implementation to configure
8215** various facets of the virtual table interface.
8216**
8217** If this interface is invoked outside the context of an xConnect or
8218** xCreate virtual table method then the behavior is undefined.
8219**
8220** At present, there is only one option that may be configured using
8221** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options
8222** may be added in the future.
8223*/
8224SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...);
8225
8226/*
8227** CAPI3REF: Virtual Table Configuration Options
8228**
8229** These macros define the various options to the
8230** [sqlite3_vtab_config()] interface that [virtual table] implementations
8231** can use to customize and optimize their behavior.
8232**
8233** <dl>
8234** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT
8235** <dd>Calls of the form
8236** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported,
8237** where X is an integer. If X is zero, then the [virtual table] whose
8238** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not
8239** support constraints. In this configuration (which is the default) if
8240** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire
8241** statement is rolled back as if [ON CONFLICT | OR ABORT] had been
8242** specified as part of the users SQL statement, regardless of the actual
8243** ON CONFLICT mode specified.
8244**
8245** If X is non-zero, then the virtual table implementation guarantees
8246** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before
8247** any modifications to internal or persistent data structures have been made.
8248** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite
8249** is able to roll back a statement or database transaction, and abandon
8250** or continue processing the current SQL statement as appropriate.
8251** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns
8252** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode
8253** had been ABORT.
8254**
8255** Virtual table implementations that are required to handle OR REPLACE
8256** must do so within the [xUpdate] method. If a call to the
8257** [sqlite3_vtab_on_conflict()] function indicates that the current ON
8258** CONFLICT policy is REPLACE, the virtual table implementation should
8259** silently replace the appropriate rows within the xUpdate callback and
8260** return SQLITE_OK. Or, if this is not possible, it may return
8261** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT
8262** constraint handling.
8263** </dl>
8264*/
8265#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1
8266
8267/*
8268** CAPI3REF: Determine The Virtual Table Conflict Policy
8269**
8270** This function may only be called from within a call to the [xUpdate] method
8271** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The
8272** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],
8273** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode
8274** of the SQL statement that triggered the call to the [xUpdate] method of the
8275** [virtual table].
8276*/
8277SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *);
8278
8279/*
8280** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE
8281**
8282** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn]
8283** method of a [virtual table], then it returns true if and only if the
8284** column is being fetched as part of an UPDATE operation during which the
8285** column value will not change. Applications might use this to substitute
8286** a lighter-weight value to return that the corresponding [xUpdate] method
8287** understands as a "no-change" value.
8288**
8289** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that
8290** the column is not changed by the UPDATE statement, they the xColumn
8291** method can optionally return without setting a result, without calling
8292** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces].
8293** In that case, [sqlite3_value_nochange(X)] will return true for the
8294** same column in the [xUpdate] method.
8295*/
8296SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*);
8297
8298/*
8299** CAPI3REF: Determine The Collation For a Virtual Table Constraint
8300**
8301** This function may only be called from within a call to the [xBestIndex]
8302** method of a [virtual table].
8303**
8304** The first argument must be the sqlite3_index_info object that is the
8305** first parameter to the xBestIndex() method. The second argument must be
8306** an index into the aConstraint[] array belonging to the sqlite3_index_info
8307** structure passed to xBestIndex. This function returns a pointer to a buffer
8308** containing the name of the collation sequence for the corresponding
8309** constraint.
8310*/
8311SQLITE_API SQLITE_EXPERIMENTAL const char *sqlite3_vtab_collation(sqlite3_index_info*,int);
8312
8313/*
8314** CAPI3REF: Conflict resolution modes
8315** KEYWORDS: {conflict resolution mode}
8316**
8317** These constants are returned by [sqlite3_vtab_on_conflict()] to
8318** inform a [virtual table] implementation what the [ON CONFLICT] mode
8319** is for the SQL statement being evaluated.
8320**
8321** Note that the [SQLITE_IGNORE] constant is also used as a potential
8322** return value from the [sqlite3_set_authorizer()] callback and that
8323** [SQLITE_ABORT] is also a [result code].
8324*/
8325#define SQLITE_ROLLBACK 1
8326/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */
8327#define SQLITE_FAIL 3
8328/* #define SQLITE_ABORT 4 // Also an error code */
8329#define SQLITE_REPLACE 5
8330
8331/*
8332** CAPI3REF: Prepared Statement Scan Status Opcodes
8333** KEYWORDS: {scanstatus options}
8334**
8335** The following constants can be used for the T parameter to the
8336** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a
8337** different metric for sqlite3_stmt_scanstatus() to return.
8338**
8339** When the value returned to V is a string, space to hold that string is
8340** managed by the prepared statement S and will be automatically freed when
8341** S is finalized.
8342**
8343** <dl>
8344** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt>
8345** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be
8346** set to the total number of times that the X-th loop has run.</dd>
8347**
8348** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt>
8349** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set
8350** to the total number of rows examined by all iterations of the X-th loop.</dd>
8351**
8352** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt>
8353** <dd>^The "double" variable pointed to by the T parameter will be set to the
8354** query planner's estimate for the average number of rows output from each
8355** iteration of the X-th loop. If the query planner's estimates was accurate,
8356** then this value will approximate the quotient NVISIT/NLOOP and the
8357** product of this value for all prior loops with the same SELECTID will
8358** be the NLOOP value for the current loop.
8359**
8360** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt>
8361** <dd>^The "const char *" variable pointed to by the T parameter will be set
8362** to a zero-terminated UTF-8 string containing the name of the index or table
8363** used for the X-th loop.
8364**
8365** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt>
8366** <dd>^The "const char *" variable pointed to by the T parameter will be set
8367** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN]
8368** description for the X-th loop.
8369**
8370** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt>
8371** <dd>^The "int" variable pointed to by the T parameter will be set to the
8372** "select-id" for the X-th loop. The select-id identifies which query or
8373** subquery the loop is part of. The main query has a select-id of zero.
8374** The select-id is the same value as is output in the first column
8375** of an [EXPLAIN QUERY PLAN] query.
8376** </dl>
8377*/
8378#define SQLITE_SCANSTAT_NLOOP 0
8379#define SQLITE_SCANSTAT_NVISIT 1
8380#define SQLITE_SCANSTAT_EST 2
8381#define SQLITE_SCANSTAT_NAME 3
8382#define SQLITE_SCANSTAT_EXPLAIN 4
8383#define SQLITE_SCANSTAT_SELECTID 5
8384
8385/*
8386** CAPI3REF: Prepared Statement Scan Status
8387** METHOD: sqlite3_stmt
8388**
8389** This interface returns information about the predicted and measured
8390** performance for pStmt. Advanced applications can use this
8391** interface to compare the predicted and the measured performance and
8392** issue warnings and/or rerun [ANALYZE] if discrepancies are found.
8393**
8394** Since this interface is expected to be rarely used, it is only
8395** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS]
8396** compile-time option.
8397**
8398** The "iScanStatusOp" parameter determines which status information to return.
8399** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior
8400** of this interface is undefined.
8401** ^The requested measurement is written into a variable pointed to by
8402** the "pOut" parameter.
8403** Parameter "idx" identifies the specific loop to retrieve statistics for.
8404** Loops are numbered starting from zero. ^If idx is out of range - less than
8405** zero or greater than or equal to the total number of loops used to implement
8406** the statement - a non-zero value is returned and the variable that pOut
8407** points to is unchanged.
8408**
8409** ^Statistics might not be available for all loops in all statements. ^In cases
8410** where there exist loops with no available statistics, this function behaves
8411** as if the loop did not exist - it returns non-zero and leave the variable
8412** that pOut points to unchanged.
8413**
8414** See also: [sqlite3_stmt_scanstatus_reset()]
8415*/
8416SQLITE_API int sqlite3_stmt_scanstatus(
8417 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */
8418 int idx, /* Index of loop to report on */
8419 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */
8420 void *pOut /* Result written here */
8421);
8422
8423/*
8424** CAPI3REF: Zero Scan-Status Counters
8425** METHOD: sqlite3_stmt
8426**
8427** ^Zero all [sqlite3_stmt_scanstatus()] related event counters.
8428**
8429** This API is only available if the library is built with pre-processor
8430** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined.
8431*/
8432SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*);
8433
8434/*
8435** CAPI3REF: Flush caches to disk mid-transaction
8436**
8437** ^If a write-transaction is open on [database connection] D when the
8438** [sqlite3_db_cacheflush(D)] interface invoked, any dirty
8439** pages in the pager-cache that are not currently in use are written out
8440** to disk. A dirty page may be in use if a database cursor created by an
8441** active SQL statement is reading from it, or if it is page 1 of a database
8442** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)]
8443** interface flushes caches for all schemas - "main", "temp", and
8444** any [attached] databases.
8445**
8446** ^If this function needs to obtain extra database locks before dirty pages
8447** can be flushed to disk, it does so. ^If those locks cannot be obtained
8448** immediately and there is a busy-handler callback configured, it is invoked
8449** in the usual manner. ^If the required lock still cannot be obtained, then
8450** the database is skipped and an attempt made to flush any dirty pages
8451** belonging to the next (if any) database. ^If any databases are skipped
8452** because locks cannot be obtained, but no other error occurs, this
8453** function returns SQLITE_BUSY.
8454**
8455** ^If any other error occurs while flushing dirty pages to disk (for
8456** example an IO error or out-of-memory condition), then processing is
8457** abandoned and an SQLite [error code] is returned to the caller immediately.
8458**
8459** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK.
8460**
8461** ^This function does not set the database handle error code or message
8462** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions.
8463*/
8464SQLITE_API int sqlite3_db_cacheflush(sqlite3*);
8465
8466/*
8467** CAPI3REF: The pre-update hook.
8468**
8469** ^These interfaces are only available if SQLite is compiled using the
8470** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option.
8471**
8472** ^The [sqlite3_preupdate_hook()] interface registers a callback function
8473** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation
8474** on a database table.
8475** ^At most one preupdate hook may be registered at a time on a single
8476** [database connection]; each call to [sqlite3_preupdate_hook()] overrides
8477** the previous setting.
8478** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()]
8479** with a NULL pointer as the second parameter.
8480** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as
8481** the first parameter to callbacks.
8482**
8483** ^The preupdate hook only fires for changes to real database tables; the
8484** preupdate hook is not invoked for changes to [virtual tables] or to
8485** system tables like sqlite_master or sqlite_stat1.
8486**
8487** ^The second parameter to the preupdate callback is a pointer to
8488** the [database connection] that registered the preupdate hook.
8489** ^The third parameter to the preupdate callback is one of the constants
8490** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the
8491** kind of update operation that is about to occur.
8492** ^(The fourth parameter to the preupdate callback is the name of the
8493** database within the database connection that is being modified. This
8494** will be "main" for the main database or "temp" for TEMP tables or
8495** the name given after the AS keyword in the [ATTACH] statement for attached
8496** databases.)^
8497** ^The fifth parameter to the preupdate callback is the name of the
8498** table that is being modified.
8499**
8500** For an UPDATE or DELETE operation on a [rowid table], the sixth
8501** parameter passed to the preupdate callback is the initial [rowid] of the
8502** row being modified or deleted. For an INSERT operation on a rowid table,
8503** or any operation on a WITHOUT ROWID table, the value of the sixth
8504** parameter is undefined. For an INSERT or UPDATE on a rowid table the
8505** seventh parameter is the final rowid value of the row being inserted
8506** or updated. The value of the seventh parameter passed to the callback
8507** function is not defined for operations on WITHOUT ROWID tables, or for
8508** INSERT operations on rowid tables.
8509**
8510** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()],
8511** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces
8512** provide additional information about a preupdate event. These routines
8513** may only be called from within a preupdate callback. Invoking any of
8514** these routines from outside of a preupdate callback or with a
8515** [database connection] pointer that is different from the one supplied
8516** to the preupdate callback results in undefined and probably undesirable
8517** behavior.
8518**
8519** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns
8520** in the row that is being inserted, updated, or deleted.
8521**
8522** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to
8523** a [protected sqlite3_value] that contains the value of the Nth column of
8524** the table row before it is updated. The N parameter must be between 0
8525** and one less than the number of columns or the behavior will be
8526** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE
8527** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the
8528** behavior is undefined. The [sqlite3_value] that P points to
8529** will be destroyed when the preupdate callback returns.
8530**
8531** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to
8532** a [protected sqlite3_value] that contains the value of the Nth column of
8533** the table row after it is updated. The N parameter must be between 0
8534** and one less than the number of columns or the behavior will be
8535** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE
8536** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the
8537** behavior is undefined. The [sqlite3_value] that P points to
8538** will be destroyed when the preupdate callback returns.
8539**
8540** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate
8541** callback was invoked as a result of a direct insert, update, or delete
8542** operation; or 1 for inserts, updates, or deletes invoked by top-level
8543** triggers; or 2 for changes resulting from triggers called by top-level
8544** triggers; and so forth.
8545**
8546** See also: [sqlite3_update_hook()]
8547*/
8548#if defined(SQLITE_ENABLE_PREUPDATE_HOOK)
8549SQLITE_API void *sqlite3_preupdate_hook(
8550 sqlite3 *db,
8551 void(*xPreUpdate)(
8552 void *pCtx, /* Copy of third arg to preupdate_hook() */
8553 sqlite3 *db, /* Database handle */
8554 int op, /* SQLITE_UPDATE, DELETE or INSERT */
8555 char const *zDb, /* Database name */
8556 char const *zName, /* Table name */
8557 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */
8558 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */
8559 ),
8560 void*
8561);
8562SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **);
8563SQLITE_API int sqlite3_preupdate_count(sqlite3 *);
8564SQLITE_API int sqlite3_preupdate_depth(sqlite3 *);
8565SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **);
8566#endif
8567
8568/*
8569** CAPI3REF: Low-level system error code
8570**
8571** ^Attempt to return the underlying operating system error code or error
8572** number that caused the most recent I/O error or failure to open a file.
8573** The return value is OS-dependent. For example, on unix systems, after
8574** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be
8575** called to get back the underlying "errno" that caused the problem, such
8576** as ENOSPC, EAUTH, EISDIR, and so forth.
8577*/
8578SQLITE_API int sqlite3_system_errno(sqlite3*);
8579
8580/*
8581** CAPI3REF: Database Snapshot
8582** KEYWORDS: {snapshot} {sqlite3_snapshot}
8583** EXPERIMENTAL
8584**
8585** An instance of the snapshot object records the state of a [WAL mode]
8586** database for some specific point in history.
8587**
8588** In [WAL mode], multiple [database connections] that are open on the
8589** same database file can each be reading a different historical version
8590** of the database file. When a [database connection] begins a read
8591** transaction, that connection sees an unchanging copy of the database
8592** as it existed for the point in time when the transaction first started.
8593** Subsequent changes to the database from other connections are not seen
8594** by the reader until a new read transaction is started.
8595**
8596** The sqlite3_snapshot object records state information about an historical
8597** version of the database file so that it is possible to later open a new read
8598** transaction that sees that historical version of the database rather than
8599** the most recent version.
8600**
8601** The constructor for this object is [sqlite3_snapshot_get()]. The
8602** [sqlite3_snapshot_open()] method causes a fresh read transaction to refer
8603** to an historical snapshot (if possible). The destructor for
8604** sqlite3_snapshot objects is [sqlite3_snapshot_free()].
8605*/
8606typedef struct sqlite3_snapshot {
8607 unsigned char hidden[48];
8608} sqlite3_snapshot;
8609
8610/*
8611** CAPI3REF: Record A Database Snapshot
8612** EXPERIMENTAL
8613**
8614** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a
8615** new [sqlite3_snapshot] object that records the current state of
8616** schema S in database connection D. ^On success, the
8617** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly
8618** created [sqlite3_snapshot] object into *P and returns SQLITE_OK.
8619** If there is not already a read-transaction open on schema S when
8620** this function is called, one is opened automatically.
8621**
8622** The following must be true for this function to succeed. If any of
8623** the following statements are false when sqlite3_snapshot_get() is
8624** called, SQLITE_ERROR is returned. The final value of *P is undefined
8625** in this case.
8626**
8627** <ul>
8628** <li> The database handle must be in [autocommit mode].
8629**
8630** <li> Schema S of [database connection] D must be a [WAL mode] database.
8631**
8632** <li> There must not be a write transaction open on schema S of database
8633** connection D.
8634**
8635** <li> One or more transactions must have been written to the current wal
8636** file since it was created on disk (by any connection). This means
8637** that a snapshot cannot be taken on a wal mode database with no wal
8638** file immediately after it is first opened. At least one transaction
8639** must be written to it first.
8640** </ul>
8641**
8642** This function may also return SQLITE_NOMEM. If it is called with the
8643** database handle in autocommit mode but fails for some other reason,
8644** whether or not a read transaction is opened on schema S is undefined.
8645**
8646** The [sqlite3_snapshot] object returned from a successful call to
8647** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()]
8648** to avoid a memory leak.
8649**
8650** The [sqlite3_snapshot_get()] interface is only available when the
8651** SQLITE_ENABLE_SNAPSHOT compile-time option is used.
8652*/
8653SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get(
8654 sqlite3 *db,
8655 const char *zSchema,
8656 sqlite3_snapshot **ppSnapshot
8657);
8658
8659/*
8660** CAPI3REF: Start a read transaction on an historical snapshot
8661** EXPERIMENTAL
8662**
8663** ^The [sqlite3_snapshot_open(D,S,P)] interface starts a
8664** read transaction for schema S of
8665** [database connection] D such that the read transaction
8666** refers to historical [snapshot] P, rather than the most
8667** recent change to the database.
8668** ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK on success
8669** or an appropriate [error code] if it fails.
8670**
8671** ^In order to succeed, a call to [sqlite3_snapshot_open(D,S,P)] must be
8672** the first operation following the [BEGIN] that takes the schema S
8673** out of [autocommit mode].
8674** ^In other words, schema S must not currently be in
8675** a transaction for [sqlite3_snapshot_open(D,S,P)] to work, but the
8676** database connection D must be out of [autocommit mode].
8677** ^A [snapshot] will fail to open if it has been overwritten by a
8678** [checkpoint].
8679** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the
8680** database connection D does not know that the database file for
8681** schema S is in [WAL mode]. A database connection might not know
8682** that the database file is in [WAL mode] if there has been no prior
8683** I/O on that database connection, or if the database entered [WAL mode]
8684** after the most recent I/O on the database connection.)^
8685** (Hint: Run "[PRAGMA application_id]" against a newly opened
8686** database connection in order to make it ready to use snapshots.)
8687**
8688** The [sqlite3_snapshot_open()] interface is only available when the
8689** SQLITE_ENABLE_SNAPSHOT compile-time option is used.
8690*/
8691SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open(
8692 sqlite3 *db,
8693 const char *zSchema,
8694 sqlite3_snapshot *pSnapshot
8695);
8696
8697/*
8698** CAPI3REF: Destroy a snapshot
8699** EXPERIMENTAL
8700**
8701** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P.
8702** The application must eventually free every [sqlite3_snapshot] object
8703** using this routine to avoid a memory leak.
8704**
8705** The [sqlite3_snapshot_free()] interface is only available when the
8706** SQLITE_ENABLE_SNAPSHOT compile-time option is used.
8707*/
8708SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*);
8709
8710/*
8711** CAPI3REF: Compare the ages of two snapshot handles.
8712** EXPERIMENTAL
8713**
8714** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages
8715** of two valid snapshot handles.
8716**
8717** If the two snapshot handles are not associated with the same database
8718** file, the result of the comparison is undefined.
8719**
8720** Additionally, the result of the comparison is only valid if both of the
8721** snapshot handles were obtained by calling sqlite3_snapshot_get() since the
8722** last time the wal file was deleted. The wal file is deleted when the
8723** database is changed back to rollback mode or when the number of database
8724** clients drops to zero. If either snapshot handle was obtained before the
8725** wal file was last deleted, the value returned by this function
8726** is undefined.
8727**
8728** Otherwise, this API returns a negative value if P1 refers to an older
8729** snapshot than P2, zero if the two handles refer to the same database
8730** snapshot, and a positive value if P1 is a newer snapshot than P2.
8731*/
8732SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp(
8733 sqlite3_snapshot *p1,
8734 sqlite3_snapshot *p2
8735);
8736
8737/*
8738** CAPI3REF: Recover snapshots from a wal file
8739** EXPERIMENTAL
8740**
8741** If all connections disconnect from a database file but do not perform
8742** a checkpoint, the existing wal file is opened along with the database
8743** file the next time the database is opened. At this point it is only
8744** possible to successfully call sqlite3_snapshot_open() to open the most
8745** recent snapshot of the database (the one at the head of the wal file),
8746** even though the wal file may contain other valid snapshots for which
8747** clients have sqlite3_snapshot handles.
8748**
8749** This function attempts to scan the wal file associated with database zDb
8750** of database handle db and make all valid snapshots available to
8751** sqlite3_snapshot_open(). It is an error if there is already a read
8752** transaction open on the database, or if the database is not a wal mode
8753** database.
8754**
8755** SQLITE_OK is returned if successful, or an SQLite error code otherwise.
8756*/
8757SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb);
8758
8759/*
8760** CAPI3REF: Serialize a database
8761**
8762** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory
8763** that is a serialization of the S database on [database connection] D.
8764** If P is not a NULL pointer, then the size of the database in bytes
8765** is written into *P.
8766**
8767** For an ordinary on-disk database file, the serialization is just a
8768** copy of the disk file. For an in-memory database or a "TEMP" database,
8769** the serialization is the same sequence of bytes which would be written
8770** to disk if that database where backed up to disk.
8771**
8772** The usual case is that sqlite3_serialize() copies the serialization of
8773** the database into memory obtained from [sqlite3_malloc64()] and returns
8774** a pointer to that memory. The caller is responsible for freeing the
8775** returned value to avoid a memory leak. However, if the F argument
8776** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations
8777** are made, and the sqlite3_serialize() function will return a pointer
8778** to the contiguous memory representation of the database that SQLite
8779** is currently using for that database, or NULL if the no such contiguous
8780** memory representation of the database exists. A contiguous memory
8781** representation of the database will usually only exist if there has
8782** been a prior call to [sqlite3_deserialize(D,S,...)] with the same
8783** values of D and S.
8784** The size of the database is written into *P even if the
8785** SQLITE_SERIALIZE_NOCOPY bit is set but no contigious copy
8786** of the database exists.
8787**
8788** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the
8789** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory
8790** allocation error occurs.
8791**
8792** This interface is only available if SQLite is compiled with the
8793** [SQLITE_ENABLE_DESERIALIZE] option.
8794*/
8795SQLITE_API unsigned char *sqlite3_serialize(
8796 sqlite3 *db, /* The database connection */
8797 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */
8798 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */
8799 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */
8800);
8801
8802/*
8803** CAPI3REF: Flags for sqlite3_serialize
8804**
8805** Zero or more of the following constants can be OR-ed together for
8806** the F argument to [sqlite3_serialize(D,S,P,F)].
8807**
8808** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return
8809** a pointer to contiguous in-memory database that it is currently using,
8810** without making a copy of the database. If SQLite is not currently using
8811** a contiguous in-memory database, then this option causes
8812** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be
8813** using a contiguous in-memory database if it has been initialized by a
8814** prior call to [sqlite3_deserialize()].
8815*/
8816#define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */
8817
8818/*
8819** CAPI3REF: Deserialize a database
8820**
8821** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the
8822** [database connection] D to disconnect from database S and then
8823** reopen S as an in-memory database based on the serialization contained
8824** in P. The serialized database P is N bytes in size. M is the size of
8825** the buffer P, which might be larger than N. If M is larger than N, and
8826** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is
8827** permitted to add content to the in-memory database as long as the total
8828** size does not exceed M bytes.
8829**
8830** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will
8831** invoke sqlite3_free() on the serialization buffer when the database
8832** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then
8833** SQLite will try to increase the buffer size using sqlite3_realloc64()
8834** if writes on the database cause it to grow larger than M bytes.
8835**
8836** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the
8837** database is currently in a read transaction or is involved in a backup
8838** operation.
8839**
8840** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the
8841** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then
8842** [sqlite3_free()] is invoked on argument P prior to returning.
8843**
8844** This interface is only available if SQLite is compiled with the
8845** [SQLITE_ENABLE_DESERIALIZE] option.
8846*/
8847SQLITE_API int sqlite3_deserialize(
8848 sqlite3 *db, /* The database connection */
8849 const char *zSchema, /* Which DB to reopen with the deserialization */
8850 unsigned char *pData, /* The serialized database content */
8851 sqlite3_int64 szDb, /* Number bytes in the deserialization */
8852 sqlite3_int64 szBuf, /* Total size of buffer pData[] */
8853 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */
8854);
8855
8856/*
8857** CAPI3REF: Flags for sqlite3_deserialize()
8858**
8859** The following are allowed values for 6th argument (the F argument) to
8860** the [sqlite3_deserialize(D,S,P,N,M,F)] interface.
8861**
8862** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization
8863** in the P argument is held in memory obtained from [sqlite3_malloc64()]
8864** and that SQLite should take ownership of this memory and automatically
8865** free it when it has finished using it. Without this flag, the caller
8866** is resposible for freeing any dynamically allocated memory.
8867**
8868** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to
8869** grow the size of the database using calls to [sqlite3_realloc64()]. This
8870** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used.
8871** Without this flag, the deserialized database cannot increase in size beyond
8872** the number of bytes specified by the M parameter.
8873**
8874** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database
8875** should be treated as read-only.
8876*/
8877#define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */
8878#define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */
8879#define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */
8880
8881/*
8882** Undo the hack that converts floating point types to integer for
8883** builds on processors without floating point support.
8884*/
8885#ifdef SQLITE_OMIT_FLOATING_POINT
8886# undef double
8887#endif
8888
8889#ifdef __cplusplus
8890} /* End of the 'extern "C"' block */
8891#endif
8892#endif /* SQLITE3_H */
8893
8894/******** Begin file sqlite3rtree.h *********/
8895/*
8896** 2010 August 30
8897**
8898** The author disclaims copyright to this source code. In place of
8899** a legal notice, here is a blessing:
8900**
8901** May you do good and not evil.
8902** May you find forgiveness for yourself and forgive others.
8903** May you share freely, never taking more than you give.
8904**
8905*************************************************************************
8906*/
8907
8908#ifndef _SQLITE3RTREE_H_
8909#define _SQLITE3RTREE_H_
8910
8911
8912#ifdef __cplusplus
8913extern "C" {
8914#endif
8915
8916typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
8917typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info;
8918
8919/* The double-precision datatype used by RTree depends on the
8920** SQLITE_RTREE_INT_ONLY compile-time option.
8921*/
8922#ifdef SQLITE_RTREE_INT_ONLY
8923 typedef sqlite3_int64 sqlite3_rtree_dbl;
8924#else
8925 typedef double sqlite3_rtree_dbl;
8926#endif
8927
8928/*
8929** Register a geometry callback named zGeom that can be used as part of an
8930** R-Tree geometry query as follows:
8931**
8932** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
8933*/
8934SQLITE_API int sqlite3_rtree_geometry_callback(
8935 sqlite3 *db,
8936 const char *zGeom,
8937 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*),
8938 void *pContext
8939);
8940
8941
8942/*
8943** A pointer to a structure of the following type is passed as the first
8944** argument to callbacks registered using rtree_geometry_callback().
8945*/
8946struct sqlite3_rtree_geometry {
8947 void *pContext; /* Copy of pContext passed to s_r_g_c() */
8948 int nParam; /* Size of array aParam[] */
8949 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */
8950 void *pUser; /* Callback implementation user data */
8951 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */
8952};
8953
8954/*
8955** Register a 2nd-generation geometry callback named zScore that can be
8956** used as part of an R-Tree geometry query as follows:
8957**
8958** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...)
8959*/
8960SQLITE_API int sqlite3_rtree_query_callback(
8961 sqlite3 *db,
8962 const char *zQueryFunc,
8963 int (*xQueryFunc)(sqlite3_rtree_query_info*),
8964 void *pContext,
8965 void (*xDestructor)(void*)
8966);
8967
8968
8969/*
8970** A pointer to a structure of the following type is passed as the
8971** argument to scored geometry callback registered using
8972** sqlite3_rtree_query_callback().
8973**
8974** Note that the first 5 fields of this structure are identical to
8975** sqlite3_rtree_geometry. This structure is a subclass of
8976** sqlite3_rtree_geometry.
8977*/
8978struct sqlite3_rtree_query_info {
8979 void *pContext; /* pContext from when function registered */
8980 int nParam; /* Number of function parameters */
8981 sqlite3_rtree_dbl *aParam; /* value of function parameters */
8982 void *pUser; /* callback can use this, if desired */
8983 void (*xDelUser)(void*); /* function to free pUser */
8984 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */
8985 unsigned int *anQueue; /* Number of pending entries in the queue */
8986 int nCoord; /* Number of coordinates */
8987 int iLevel; /* Level of current node or entry */
8988 int mxLevel; /* The largest iLevel value in the tree */
8989 sqlite3_int64 iRowid; /* Rowid for current entry */
8990 sqlite3_rtree_dbl rParentScore; /* Score of parent node */
8991 int eParentWithin; /* Visibility of parent node */
8992 int eWithin; /* OUT: Visiblity */
8993 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */
8994 /* The following fields are only available in 3.8.11 and later */
8995 sqlite3_value **apSqlParam; /* Original SQL values of parameters */
8996};
8997
8998/*
8999** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin.
9000*/
9001#define NOT_WITHIN 0 /* Object completely outside of query region */
9002#define PARTLY_WITHIN 1 /* Object partially overlaps query region */
9003#define FULLY_WITHIN 2 /* Object fully contained within query region */
9004
9005
9006#ifdef __cplusplus
9007} /* end of the 'extern "C"' block */
9008#endif
9009
9010#endif /* ifndef _SQLITE3RTREE_H_ */
9011
9012/******** End of sqlite3rtree.h *********/
9013/******** Begin file sqlite3session.h *********/
9014
9015#if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION)
9016#define __SQLITESESSION_H_ 1
9017
9018/*
9019** Make sure we can call this stuff from C++.
9020*/
9021#ifdef __cplusplus
9022extern "C" {
9023#endif
9024
9025
9026/*
9027** CAPI3REF: Session Object Handle
9028**
9029** An instance of this object is a [session] that can be used to
9030** record changes to a database.
9031*/
9032typedef struct sqlite3_session sqlite3_session;
9033
9034/*
9035** CAPI3REF: Changeset Iterator Handle
9036**
9037** An instance of this object acts as a cursor for iterating
9038** over the elements of a [changeset] or [patchset].
9039*/
9040typedef struct sqlite3_changeset_iter sqlite3_changeset_iter;
9041
9042/*
9043** CAPI3REF: Create A New Session Object
9044** CONSTRUCTOR: sqlite3_session
9045**
9046** Create a new session object attached to database handle db. If successful,
9047** a pointer to the new object is written to *ppSession and SQLITE_OK is
9048** returned. If an error occurs, *ppSession is set to NULL and an SQLite
9049** error code (e.g. SQLITE_NOMEM) is returned.
9050**
9051** It is possible to create multiple session objects attached to a single
9052** database handle.
9053**
9054** Session objects created using this function should be deleted using the
9055** [sqlite3session_delete()] function before the database handle that they
9056** are attached to is itself closed. If the database handle is closed before
9057** the session object is deleted, then the results of calling any session
9058** module function, including [sqlite3session_delete()] on the session object
9059** are undefined.
9060**
9061** Because the session module uses the [sqlite3_preupdate_hook()] API, it
9062** is not possible for an application to register a pre-update hook on a
9063** database handle that has one or more session objects attached. Nor is
9064** it possible to create a session object attached to a database handle for
9065** which a pre-update hook is already defined. The results of attempting
9066** either of these things are undefined.
9067**
9068** The session object will be used to create changesets for tables in
9069** database zDb, where zDb is either "main", or "temp", or the name of an
9070** attached database. It is not an error if database zDb is not attached
9071** to the database when the session object is created.
9072*/
9073SQLITE_API int sqlite3session_create(
9074 sqlite3 *db, /* Database handle */
9075 const char *zDb, /* Name of db (e.g. "main") */
9076 sqlite3_session **ppSession /* OUT: New session object */
9077);
9078
9079/*
9080** CAPI3REF: Delete A Session Object
9081** DESTRUCTOR: sqlite3_session
9082**
9083** Delete a session object previously allocated using
9084** [sqlite3session_create()]. Once a session object has been deleted, the
9085** results of attempting to use pSession with any other session module
9086** function are undefined.
9087**
9088** Session objects must be deleted before the database handle to which they
9089** are attached is closed. Refer to the documentation for
9090** [sqlite3session_create()] for details.
9091*/
9092SQLITE_API void sqlite3session_delete(sqlite3_session *pSession);
9093
9094
9095/*
9096** CAPI3REF: Enable Or Disable A Session Object
9097** METHOD: sqlite3_session
9098**
9099** Enable or disable the recording of changes by a session object. When
9100** enabled, a session object records changes made to the database. When
9101** disabled - it does not. A newly created session object is enabled.
9102** Refer to the documentation for [sqlite3session_changeset()] for further
9103** details regarding how enabling and disabling a session object affects
9104** the eventual changesets.
9105**
9106** Passing zero to this function disables the session. Passing a value
9107** greater than zero enables it. Passing a value less than zero is a
9108** no-op, and may be used to query the current state of the session.
9109**
9110** The return value indicates the final state of the session object: 0 if
9111** the session is disabled, or 1 if it is enabled.
9112*/
9113SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable);
9114
9115/*
9116** CAPI3REF: Set Or Clear the Indirect Change Flag
9117** METHOD: sqlite3_session
9118**
9119** Each change recorded by a session object is marked as either direct or
9120** indirect. A change is marked as indirect if either:
9121**
9122** <ul>
9123** <li> The session object "indirect" flag is set when the change is
9124** made, or
9125** <li> The change is made by an SQL trigger or foreign key action
9126** instead of directly as a result of a users SQL statement.
9127** </ul>
9128**
9129** If a single row is affected by more than one operation within a session,
9130** then the change is considered indirect if all operations meet the criteria
9131** for an indirect change above, or direct otherwise.
9132**
9133** This function is used to set, clear or query the session object indirect
9134** flag. If the second argument passed to this function is zero, then the
9135** indirect flag is cleared. If it is greater than zero, the indirect flag
9136** is set. Passing a value less than zero does not modify the current value
9137** of the indirect flag, and may be used to query the current state of the
9138** indirect flag for the specified session object.
9139**
9140** The return value indicates the final state of the indirect flag: 0 if
9141** it is clear, or 1 if it is set.
9142*/
9143SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect);
9144
9145/*
9146** CAPI3REF: Attach A Table To A Session Object
9147** METHOD: sqlite3_session
9148**
9149** If argument zTab is not NULL, then it is the name of a table to attach
9150** to the session object passed as the first argument. All subsequent changes
9151** made to the table while the session object is enabled will be recorded. See
9152** documentation for [sqlite3session_changeset()] for further details.
9153**
9154** Or, if argument zTab is NULL, then changes are recorded for all tables
9155** in the database. If additional tables are added to the database (by
9156** executing "CREATE TABLE" statements) after this call is made, changes for
9157** the new tables are also recorded.
9158**
9159** Changes can only be recorded for tables that have a PRIMARY KEY explicitly
9160** defined as part of their CREATE TABLE statement. It does not matter if the
9161** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY
9162** KEY may consist of a single column, or may be a composite key.
9163**
9164** It is not an error if the named table does not exist in the database. Nor
9165** is it an error if the named table does not have a PRIMARY KEY. However,
9166** no changes will be recorded in either of these scenarios.
9167**
9168** Changes are not recorded for individual rows that have NULL values stored
9169** in one or more of their PRIMARY KEY columns.
9170**
9171** SQLITE_OK is returned if the call completes without error. Or, if an error
9172** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned.
9173**
9174** <h3>Special sqlite_stat1 Handling</h3>
9175**
9176** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to
9177** some of the rules above. In SQLite, the schema of sqlite_stat1 is:
9178** <pre>
9179** &nbsp; CREATE TABLE sqlite_stat1(tbl,idx,stat)
9180** </pre>
9181**
9182** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are
9183** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes
9184** are recorded for rows for which (idx IS NULL) is true. However, for such
9185** rows a zero-length blob (SQL value X'') is stored in the changeset or
9186** patchset instead of a NULL value. This allows such changesets to be
9187** manipulated by legacy implementations of sqlite3changeset_invert(),
9188** concat() and similar.
9189**
9190** The sqlite3changeset_apply() function automatically converts the
9191** zero-length blob back to a NULL value when updating the sqlite_stat1
9192** table. However, if the application calls sqlite3changeset_new(),
9193** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset
9194** iterator directly (including on a changeset iterator passed to a
9195** conflict-handler callback) then the X'' value is returned. The application
9196** must translate X'' to NULL itself if required.
9197**
9198** Legacy (older than 3.22.0) versions of the sessions module cannot capture
9199** changes made to the sqlite_stat1 table. Legacy versions of the
9200** sqlite3changeset_apply() function silently ignore any modifications to the
9201** sqlite_stat1 table that are part of a changeset or patchset.
9202*/
9203SQLITE_API int sqlite3session_attach(
9204 sqlite3_session *pSession, /* Session object */
9205 const char *zTab /* Table name */
9206);
9207
9208/*
9209** CAPI3REF: Set a table filter on a Session Object.
9210** METHOD: sqlite3_session
9211**
9212** The second argument (xFilter) is the "filter callback". For changes to rows
9213** in tables that are not attached to the Session object, the filter is called
9214** to determine whether changes to the table's rows should be tracked or not.
9215** If xFilter returns 0, changes is not tracked. Note that once a table is
9216** attached, xFilter will not be called again.
9217*/
9218SQLITE_API void sqlite3session_table_filter(
9219 sqlite3_session *pSession, /* Session object */
9220 int(*xFilter)(
9221 void *pCtx, /* Copy of third arg to _filter_table() */
9222 const char *zTab /* Table name */
9223 ),
9224 void *pCtx /* First argument passed to xFilter */
9225);
9226
9227/*
9228** CAPI3REF: Generate A Changeset From A Session Object
9229** METHOD: sqlite3_session
9230**
9231** Obtain a changeset containing changes to the tables attached to the
9232** session object passed as the first argument. If successful,
9233** set *ppChangeset to point to a buffer containing the changeset
9234** and *pnChangeset to the size of the changeset in bytes before returning
9235** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to
9236** zero and return an SQLite error code.
9237**
9238** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes,
9239** each representing a change to a single row of an attached table. An INSERT
9240** change contains the values of each field of a new database row. A DELETE
9241** contains the original values of each field of a deleted database row. An
9242** UPDATE change contains the original values of each field of an updated
9243** database row along with the updated values for each updated non-primary-key
9244** column. It is not possible for an UPDATE change to represent a change that
9245** modifies the values of primary key columns. If such a change is made, it
9246** is represented in a changeset as a DELETE followed by an INSERT.
9247**
9248** Changes are not recorded for rows that have NULL values stored in one or
9249** more of their PRIMARY KEY columns. If such a row is inserted or deleted,
9250** no corresponding change is present in the changesets returned by this
9251** function. If an existing row with one or more NULL values stored in
9252** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL,
9253** only an INSERT is appears in the changeset. Similarly, if an existing row
9254** with non-NULL PRIMARY KEY values is updated so that one or more of its
9255** PRIMARY KEY columns are set to NULL, the resulting changeset contains a
9256** DELETE change only.
9257**
9258** The contents of a changeset may be traversed using an iterator created
9259** using the [sqlite3changeset_start()] API. A changeset may be applied to
9260** a database with a compatible schema using the [sqlite3changeset_apply()]
9261** API.
9262**
9263** Within a changeset generated by this function, all changes related to a
9264** single table are grouped together. In other words, when iterating through
9265** a changeset or when applying a changeset to a database, all changes related
9266** to a single table are processed before moving on to the next table. Tables
9267** are sorted in the same order in which they were attached (or auto-attached)
9268** to the sqlite3_session object. The order in which the changes related to
9269** a single table are stored is undefined.
9270**
9271** Following a successful call to this function, it is the responsibility of
9272** the caller to eventually free the buffer that *ppChangeset points to using
9273** [sqlite3_free()].
9274**
9275** <h3>Changeset Generation</h3>
9276**
9277** Once a table has been attached to a session object, the session object
9278** records the primary key values of all new rows inserted into the table.
9279** It also records the original primary key and other column values of any
9280** deleted or updated rows. For each unique primary key value, data is only
9281** recorded once - the first time a row with said primary key is inserted,
9282** updated or deleted in the lifetime of the session.
9283**
9284** There is one exception to the previous paragraph: when a row is inserted,
9285** updated or deleted, if one or more of its primary key columns contain a
9286** NULL value, no record of the change is made.
9287**
9288** The session object therefore accumulates two types of records - those
9289** that consist of primary key values only (created when the user inserts
9290** a new record) and those that consist of the primary key values and the
9291** original values of other table columns (created when the users deletes
9292** or updates a record).
9293**
9294** When this function is called, the requested changeset is created using
9295** both the accumulated records and the current contents of the database
9296** file. Specifically:
9297**
9298** <ul>
9299** <li> For each record generated by an insert, the database is queried
9300** for a row with a matching primary key. If one is found, an INSERT
9301** change is added to the changeset. If no such row is found, no change
9302** is added to the changeset.
9303**
9304** <li> For each record generated by an update or delete, the database is
9305** queried for a row with a matching primary key. If such a row is
9306** found and one or more of the non-primary key fields have been
9307** modified from their original values, an UPDATE change is added to
9308** the changeset. Or, if no such row is found in the table, a DELETE
9309** change is added to the changeset. If there is a row with a matching
9310** primary key in the database, but all fields contain their original
9311** values, no change is added to the changeset.
9312** </ul>
9313**
9314** This means, amongst other things, that if a row is inserted and then later
9315** deleted while a session object is active, neither the insert nor the delete
9316** will be present in the changeset. Or if a row is deleted and then later a
9317** row with the same primary key values inserted while a session object is
9318** active, the resulting changeset will contain an UPDATE change instead of
9319** a DELETE and an INSERT.
9320**
9321** When a session object is disabled (see the [sqlite3session_enable()] API),
9322** it does not accumulate records when rows are inserted, updated or deleted.
9323** This may appear to have some counter-intuitive effects if a single row
9324** is written to more than once during a session. For example, if a row
9325** is inserted while a session object is enabled, then later deleted while
9326** the same session object is disabled, no INSERT record will appear in the
9327** changeset, even though the delete took place while the session was disabled.
9328** Or, if one field of a row is updated while a session is disabled, and
9329** another field of the same row is updated while the session is enabled, the
9330** resulting changeset will contain an UPDATE change that updates both fields.
9331*/
9332SQLITE_API int sqlite3session_changeset(
9333 sqlite3_session *pSession, /* Session object */
9334 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */
9335 void **ppChangeset /* OUT: Buffer containing changeset */
9336);
9337
9338/*
9339** CAPI3REF: Load The Difference Between Tables Into A Session
9340** METHOD: sqlite3_session
9341**
9342** If it is not already attached to the session object passed as the first
9343** argument, this function attaches table zTbl in the same manner as the
9344** [sqlite3session_attach()] function. If zTbl does not exist, or if it
9345** does not have a primary key, this function is a no-op (but does not return
9346** an error).
9347**
9348** Argument zFromDb must be the name of a database ("main", "temp" etc.)
9349** attached to the same database handle as the session object that contains
9350** a table compatible with the table attached to the session by this function.
9351** A table is considered compatible if it:
9352**
9353** <ul>
9354** <li> Has the same name,
9355** <li> Has the same set of columns declared in the same order, and
9356** <li> Has the same PRIMARY KEY definition.
9357** </ul>
9358**
9359** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables
9360** are compatible but do not have any PRIMARY KEY columns, it is not an error
9361** but no changes are added to the session object. As with other session
9362** APIs, tables without PRIMARY KEYs are simply ignored.
9363**
9364** This function adds a set of changes to the session object that could be
9365** used to update the table in database zFrom (call this the "from-table")
9366** so that its content is the same as the table attached to the session
9367** object (call this the "to-table"). Specifically:
9368**
9369** <ul>
9370** <li> For each row (primary key) that exists in the to-table but not in
9371** the from-table, an INSERT record is added to the session object.
9372**
9373** <li> For each row (primary key) that exists in the to-table but not in
9374** the from-table, a DELETE record is added to the session object.
9375**
9376** <li> For each row (primary key) that exists in both tables, but features
9377** different non-PK values in each, an UPDATE record is added to the
9378** session.
9379** </ul>
9380**
9381** To clarify, if this function is called and then a changeset constructed
9382** using [sqlite3session_changeset()], then after applying that changeset to
9383** database zFrom the contents of the two compatible tables would be
9384** identical.
9385**
9386** It an error if database zFrom does not exist or does not contain the
9387** required compatible table.
9388**
9389** If the operation successful, SQLITE_OK is returned. Otherwise, an SQLite
9390** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg
9391** may be set to point to a buffer containing an English language error
9392** message. It is the responsibility of the caller to free this buffer using
9393** sqlite3_free().
9394*/
9395SQLITE_API int sqlite3session_diff(
9396 sqlite3_session *pSession,
9397 const char *zFromDb,
9398 const char *zTbl,
9399 char **pzErrMsg
9400);
9401
9402
9403/*
9404** CAPI3REF: Generate A Patchset From A Session Object
9405** METHOD: sqlite3_session
9406**
9407** The differences between a patchset and a changeset are that:
9408**
9409** <ul>
9410** <li> DELETE records consist of the primary key fields only. The
9411** original values of other fields are omitted.
9412** <li> The original values of any modified fields are omitted from
9413** UPDATE records.
9414** </ul>
9415**
9416** A patchset blob may be used with up to date versions of all
9417** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(),
9418** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly,
9419** attempting to use a patchset blob with old versions of the
9420** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error.
9421**
9422** Because the non-primary key "old.*" fields are omitted, no
9423** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset
9424** is passed to the sqlite3changeset_apply() API. Other conflict types work
9425** in the same way as for changesets.
9426**
9427** Changes within a patchset are ordered in the same way as for changesets
9428** generated by the sqlite3session_changeset() function (i.e. all changes for
9429** a single table are grouped together, tables appear in the order in which
9430** they were attached to the session object).
9431*/
9432SQLITE_API int sqlite3session_patchset(
9433 sqlite3_session *pSession, /* Session object */
9434 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */
9435 void **ppPatchset /* OUT: Buffer containing patchset */
9436);
9437
9438/*
9439** CAPI3REF: Test if a changeset has recorded any changes.
9440**
9441** Return non-zero if no changes to attached tables have been recorded by
9442** the session object passed as the first argument. Otherwise, if one or
9443** more changes have been recorded, return zero.
9444**
9445** Even if this function returns zero, it is possible that calling
9446** [sqlite3session_changeset()] on the session handle may still return a
9447** changeset that contains no changes. This can happen when a row in
9448** an attached table is modified and then later on the original values
9449** are restored. However, if this function returns non-zero, then it is
9450** guaranteed that a call to sqlite3session_changeset() will return a
9451** changeset containing zero changes.
9452*/
9453SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession);
9454
9455/*
9456** CAPI3REF: Create An Iterator To Traverse A Changeset
9457** CONSTRUCTOR: sqlite3_changeset_iter
9458**
9459** Create an iterator used to iterate through the contents of a changeset.
9460** If successful, *pp is set to point to the iterator handle and SQLITE_OK
9461** is returned. Otherwise, if an error occurs, *pp is set to zero and an
9462** SQLite error code is returned.
9463**
9464** The following functions can be used to advance and query a changeset
9465** iterator created by this function:
9466**
9467** <ul>
9468** <li> [sqlite3changeset_next()]
9469** <li> [sqlite3changeset_op()]
9470** <li> [sqlite3changeset_new()]
9471** <li> [sqlite3changeset_old()]
9472** </ul>
9473**
9474** It is the responsibility of the caller to eventually destroy the iterator
9475** by passing it to [sqlite3changeset_finalize()]. The buffer containing the
9476** changeset (pChangeset) must remain valid until after the iterator is
9477** destroyed.
9478**
9479** Assuming the changeset blob was created by one of the
9480** [sqlite3session_changeset()], [sqlite3changeset_concat()] or
9481** [sqlite3changeset_invert()] functions, all changes within the changeset
9482** that apply to a single table are grouped together. This means that when
9483** an application iterates through a changeset using an iterator created by
9484** this function, all changes that relate to a single table are visited
9485** consecutively. There is no chance that the iterator will visit a change
9486** the applies to table X, then one for table Y, and then later on visit
9487** another change for table X.
9488*/
9489SQLITE_API int sqlite3changeset_start(
9490 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
9491 int nChangeset, /* Size of changeset blob in bytes */
9492 void *pChangeset /* Pointer to blob containing changeset */
9493);
9494
9495
9496/*
9497** CAPI3REF: Advance A Changeset Iterator
9498** METHOD: sqlite3_changeset_iter
9499**
9500** This function may only be used with iterators created by function
9501** [sqlite3changeset_start()]. If it is called on an iterator passed to
9502** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE
9503** is returned and the call has no effect.
9504**
9505** Immediately after an iterator is created by sqlite3changeset_start(), it
9506** does not point to any change in the changeset. Assuming the changeset
9507** is not empty, the first call to this function advances the iterator to
9508** point to the first change in the changeset. Each subsequent call advances
9509** the iterator to point to the next change in the changeset (if any). If
9510** no error occurs and the iterator points to a valid change after a call
9511** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned.
9512** Otherwise, if all changes in the changeset have already been visited,
9513** SQLITE_DONE is returned.
9514**
9515** If an error occurs, an SQLite error code is returned. Possible error
9516** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or
9517** SQLITE_NOMEM.
9518*/
9519SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter);
9520
9521/*
9522** CAPI3REF: Obtain The Current Operation From A Changeset Iterator
9523** METHOD: sqlite3_changeset_iter
9524**
9525** The pIter argument passed to this function may either be an iterator
9526** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
9527** created by [sqlite3changeset_start()]. In the latter case, the most recent
9528** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this
9529** is not the case, this function returns [SQLITE_MISUSE].
9530**
9531** If argument pzTab is not NULL, then *pzTab is set to point to a
9532** nul-terminated utf-8 encoded string containing the name of the table
9533** affected by the current change. The buffer remains valid until either
9534** sqlite3changeset_next() is called on the iterator or until the
9535** conflict-handler function returns. If pnCol is not NULL, then *pnCol is
9536** set to the number of columns in the table affected by the change. If
9537** pbIncorrect is not NULL, then *pbIndirect is set to true (1) if the change
9538** is an indirect change, or false (0) otherwise. See the documentation for
9539** [sqlite3session_indirect()] for a description of direct and indirect
9540** changes. Finally, if pOp is not NULL, then *pOp is set to one of
9541** [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], depending on the
9542** type of change that the iterator currently points to.
9543**
9544** If no error occurs, SQLITE_OK is returned. If an error does occur, an
9545** SQLite error code is returned. The values of the output variables may not
9546** be trusted in this case.
9547*/
9548SQLITE_API int sqlite3changeset_op(
9549 sqlite3_changeset_iter *pIter, /* Iterator object */
9550 const char **pzTab, /* OUT: Pointer to table name */
9551 int *pnCol, /* OUT: Number of columns in table */
9552 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */
9553 int *pbIndirect /* OUT: True for an 'indirect' change */
9554);
9555
9556/*
9557** CAPI3REF: Obtain The Primary Key Definition Of A Table
9558** METHOD: sqlite3_changeset_iter
9559**
9560** For each modified table, a changeset includes the following:
9561**
9562** <ul>
9563** <li> The number of columns in the table, and
9564** <li> Which of those columns make up the tables PRIMARY KEY.
9565** </ul>
9566**
9567** This function is used to find which columns comprise the PRIMARY KEY of
9568** the table modified by the change that iterator pIter currently points to.
9569** If successful, *pabPK is set to point to an array of nCol entries, where
9570** nCol is the number of columns in the table. Elements of *pabPK are set to
9571** 0x01 if the corresponding column is part of the tables primary key, or
9572** 0x00 if it is not.
9573**
9574** If argument pnCol is not NULL, then *pnCol is set to the number of columns
9575** in the table.
9576**
9577** If this function is called when the iterator does not point to a valid
9578** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise,
9579** SQLITE_OK is returned and the output variables populated as described
9580** above.
9581*/
9582SQLITE_API int sqlite3changeset_pk(
9583 sqlite3_changeset_iter *pIter, /* Iterator object */
9584 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */
9585 int *pnCol /* OUT: Number of entries in output array */
9586);
9587
9588/*
9589** CAPI3REF: Obtain old.* Values From A Changeset Iterator
9590** METHOD: sqlite3_changeset_iter
9591**
9592** The pIter argument passed to this function may either be an iterator
9593** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
9594** created by [sqlite3changeset_start()]. In the latter case, the most recent
9595** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
9596** Furthermore, it may only be called if the type of change that the iterator
9597** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise,
9598** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
9599**
9600** Argument iVal must be greater than or equal to 0, and less than the number
9601** of columns in the table affected by the current change. Otherwise,
9602** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
9603**
9604** If successful, this function sets *ppValue to point to a protected
9605** sqlite3_value object containing the iVal'th value from the vector of
9606** original row values stored as part of the UPDATE or DELETE change and
9607** returns SQLITE_OK. The name of the function comes from the fact that this
9608** is similar to the "old.*" columns available to update or delete triggers.
9609**
9610** If some other error occurs (e.g. an OOM condition), an SQLite error code
9611** is returned and *ppValue is set to NULL.
9612*/
9613SQLITE_API int sqlite3changeset_old(
9614 sqlite3_changeset_iter *pIter, /* Changeset iterator */
9615 int iVal, /* Column number */
9616 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */
9617);
9618
9619/*
9620** CAPI3REF: Obtain new.* Values From A Changeset Iterator
9621** METHOD: sqlite3_changeset_iter
9622**
9623** The pIter argument passed to this function may either be an iterator
9624** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
9625** created by [sqlite3changeset_start()]. In the latter case, the most recent
9626** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
9627** Furthermore, it may only be called if the type of change that the iterator
9628** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise,
9629** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
9630**
9631** Argument iVal must be greater than or equal to 0, and less than the number
9632** of columns in the table affected by the current change. Otherwise,
9633** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
9634**
9635** If successful, this function sets *ppValue to point to a protected
9636** sqlite3_value object containing the iVal'th value from the vector of
9637** new row values stored as part of the UPDATE or INSERT change and
9638** returns SQLITE_OK. If the change is an UPDATE and does not include
9639** a new value for the requested column, *ppValue is set to NULL and
9640** SQLITE_OK returned. The name of the function comes from the fact that
9641** this is similar to the "new.*" columns available to update or delete
9642** triggers.
9643**
9644** If some other error occurs (e.g. an OOM condition), an SQLite error code
9645** is returned and *ppValue is set to NULL.
9646*/
9647SQLITE_API int sqlite3changeset_new(
9648 sqlite3_changeset_iter *pIter, /* Changeset iterator */
9649 int iVal, /* Column number */
9650 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */
9651);
9652
9653/*
9654** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator
9655** METHOD: sqlite3_changeset_iter
9656**
9657** This function should only be used with iterator objects passed to a
9658** conflict-handler callback by [sqlite3changeset_apply()] with either
9659** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function
9660** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue
9661** is set to NULL.
9662**
9663** Argument iVal must be greater than or equal to 0, and less than the number
9664** of columns in the table affected by the current change. Otherwise,
9665** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
9666**
9667** If successful, this function sets *ppValue to point to a protected
9668** sqlite3_value object containing the iVal'th value from the
9669** "conflicting row" associated with the current conflict-handler callback
9670** and returns SQLITE_OK.
9671**
9672** If some other error occurs (e.g. an OOM condition), an SQLite error code
9673** is returned and *ppValue is set to NULL.
9674*/
9675SQLITE_API int sqlite3changeset_conflict(
9676 sqlite3_changeset_iter *pIter, /* Changeset iterator */
9677 int iVal, /* Column number */
9678 sqlite3_value **ppValue /* OUT: Value from conflicting row */
9679);
9680
9681/*
9682** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations
9683** METHOD: sqlite3_changeset_iter
9684**
9685** This function may only be called with an iterator passed to an
9686** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case
9687** it sets the output variable to the total number of known foreign key
9688** violations in the destination database and returns SQLITE_OK.
9689**
9690** In all other cases this function returns SQLITE_MISUSE.
9691*/
9692SQLITE_API int sqlite3changeset_fk_conflicts(
9693 sqlite3_changeset_iter *pIter, /* Changeset iterator */
9694 int *pnOut /* OUT: Number of FK violations */
9695);
9696
9697
9698/*
9699** CAPI3REF: Finalize A Changeset Iterator
9700** METHOD: sqlite3_changeset_iter
9701**
9702** This function is used to finalize an iterator allocated with
9703** [sqlite3changeset_start()].
9704**
9705** This function should only be called on iterators created using the
9706** [sqlite3changeset_start()] function. If an application calls this
9707** function with an iterator passed to a conflict-handler by
9708** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the
9709** call has no effect.
9710**
9711** If an error was encountered within a call to an sqlite3changeset_xxx()
9712** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an
9713** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding
9714** to that error is returned by this function. Otherwise, SQLITE_OK is
9715** returned. This is to allow the following pattern (pseudo-code):
9716**
9717** <pre>
9718** sqlite3changeset_start();
9719** while( SQLITE_ROW==sqlite3changeset_next() ){
9720** // Do something with change.
9721** }
9722** rc = sqlite3changeset_finalize();
9723** if( rc!=SQLITE_OK ){
9724** // An error has occurred
9725** }
9726** </pre>
9727*/
9728SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter);
9729
9730/*
9731** CAPI3REF: Invert A Changeset
9732**
9733** This function is used to "invert" a changeset object. Applying an inverted
9734** changeset to a database reverses the effects of applying the uninverted
9735** changeset. Specifically:
9736**
9737** <ul>
9738** <li> Each DELETE change is changed to an INSERT, and
9739** <li> Each INSERT change is changed to a DELETE, and
9740** <li> For each UPDATE change, the old.* and new.* values are exchanged.
9741** </ul>
9742**
9743** This function does not change the order in which changes appear within
9744** the changeset. It merely reverses the sense of each individual change.
9745**
9746** If successful, a pointer to a buffer containing the inverted changeset
9747** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and
9748** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are
9749** zeroed and an SQLite error code returned.
9750**
9751** It is the responsibility of the caller to eventually call sqlite3_free()
9752** on the *ppOut pointer to free the buffer allocation following a successful
9753** call to this function.
9754**
9755** WARNING/TODO: This function currently assumes that the input is a valid
9756** changeset. If it is not, the results are undefined.
9757*/
9758SQLITE_API int sqlite3changeset_invert(
9759 int nIn, const void *pIn, /* Input changeset */
9760 int *pnOut, void **ppOut /* OUT: Inverse of input */
9761);
9762
9763/*
9764** CAPI3REF: Concatenate Two Changeset Objects
9765**
9766** This function is used to concatenate two changesets, A and B, into a
9767** single changeset. The result is a changeset equivalent to applying
9768** changeset A followed by changeset B.
9769**
9770** This function combines the two input changesets using an
9771** sqlite3_changegroup object. Calling it produces similar results as the
9772** following code fragment:
9773**
9774** <pre>
9775** sqlite3_changegroup *pGrp;
9776** rc = sqlite3_changegroup_new(&pGrp);
9777** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA);
9778** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB);
9779** if( rc==SQLITE_OK ){
9780** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut);
9781** }else{
9782** *ppOut = 0;
9783** *pnOut = 0;
9784** }
9785** </pre>
9786**
9787** Refer to the sqlite3_changegroup documentation below for details.
9788*/
9789SQLITE_API int sqlite3changeset_concat(
9790 int nA, /* Number of bytes in buffer pA */
9791 void *pA, /* Pointer to buffer containing changeset A */
9792 int nB, /* Number of bytes in buffer pB */
9793 void *pB, /* Pointer to buffer containing changeset B */
9794 int *pnOut, /* OUT: Number of bytes in output changeset */
9795 void **ppOut /* OUT: Buffer containing output changeset */
9796);
9797
9798
9799/*
9800** CAPI3REF: Changegroup Handle
9801**
9802** A changegroup is an object used to combine two or more
9803** [changesets] or [patchsets]
9804*/
9805typedef struct sqlite3_changegroup sqlite3_changegroup;
9806
9807/*
9808** CAPI3REF: Create A New Changegroup Object
9809** CONSTRUCTOR: sqlite3_changegroup
9810**
9811** An sqlite3_changegroup object is used to combine two or more changesets
9812** (or patchsets) into a single changeset (or patchset). A single changegroup
9813** object may combine changesets or patchsets, but not both. The output is
9814** always in the same format as the input.
9815**
9816** If successful, this function returns SQLITE_OK and populates (*pp) with
9817** a pointer to a new sqlite3_changegroup object before returning. The caller
9818** should eventually free the returned object using a call to
9819** sqlite3changegroup_delete(). If an error occurs, an SQLite error code
9820** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL.
9821**
9822** The usual usage pattern for an sqlite3_changegroup object is as follows:
9823**
9824** <ul>
9825** <li> It is created using a call to sqlite3changegroup_new().
9826**
9827** <li> Zero or more changesets (or patchsets) are added to the object
9828** by calling sqlite3changegroup_add().
9829**
9830** <li> The result of combining all input changesets together is obtained
9831** by the application via a call to sqlite3changegroup_output().
9832**
9833** <li> The object is deleted using a call to sqlite3changegroup_delete().
9834** </ul>
9835**
9836** Any number of calls to add() and output() may be made between the calls to
9837** new() and delete(), and in any order.
9838**
9839** As well as the regular sqlite3changegroup_add() and
9840** sqlite3changegroup_output() functions, also available are the streaming
9841** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm().
9842*/
9843SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp);
9844
9845/*
9846** CAPI3REF: Add A Changeset To A Changegroup
9847** METHOD: sqlite3_changegroup
9848**
9849** Add all changes within the changeset (or patchset) in buffer pData (size
9850** nData bytes) to the changegroup.
9851**
9852** If the buffer contains a patchset, then all prior calls to this function
9853** on the same changegroup object must also have specified patchsets. Or, if
9854** the buffer contains a changeset, so must have the earlier calls to this
9855** function. Otherwise, SQLITE_ERROR is returned and no changes are added
9856** to the changegroup.
9857**
9858** Rows within the changeset and changegroup are identified by the values in
9859** their PRIMARY KEY columns. A change in the changeset is considered to
9860** apply to the same row as a change already present in the changegroup if
9861** the two rows have the same primary key.
9862**
9863** Changes to rows that do not already appear in the changegroup are
9864** simply copied into it. Or, if both the new changeset and the changegroup
9865** contain changes that apply to a single row, the final contents of the
9866** changegroup depends on the type of each change, as follows:
9867**
9868** <table border=1 style="margin-left:8ex;margin-right:8ex">
9869** <tr><th style="white-space:pre">Existing Change </th>
9870** <th style="white-space:pre">New Change </th>
9871** <th>Output Change
9872** <tr><td>INSERT <td>INSERT <td>
9873** The new change is ignored. This case does not occur if the new
9874** changeset was recorded immediately after the changesets already
9875** added to the changegroup.
9876** <tr><td>INSERT <td>UPDATE <td>
9877** The INSERT change remains in the changegroup. The values in the
9878** INSERT change are modified as if the row was inserted by the
9879** existing change and then updated according to the new change.
9880** <tr><td>INSERT <td>DELETE <td>
9881** The existing INSERT is removed from the changegroup. The DELETE is
9882** not added.
9883** <tr><td>UPDATE <td>INSERT <td>
9884** The new change is ignored. This case does not occur if the new
9885** changeset was recorded immediately after the changesets already
9886** added to the changegroup.
9887** <tr><td>UPDATE <td>UPDATE <td>
9888** The existing UPDATE remains within the changegroup. It is amended
9889** so that the accompanying values are as if the row was updated once
9890** by the existing change and then again by the new change.
9891** <tr><td>UPDATE <td>DELETE <td>
9892** The existing UPDATE is replaced by the new DELETE within the
9893** changegroup.
9894** <tr><td>DELETE <td>INSERT <td>
9895** If one or more of the column values in the row inserted by the
9896** new change differ from those in the row deleted by the existing
9897** change, the existing DELETE is replaced by an UPDATE within the
9898** changegroup. Otherwise, if the inserted row is exactly the same
9899** as the deleted row, the existing DELETE is simply discarded.
9900** <tr><td>DELETE <td>UPDATE <td>
9901** The new change is ignored. This case does not occur if the new
9902** changeset was recorded immediately after the changesets already
9903** added to the changegroup.
9904** <tr><td>DELETE <td>DELETE <td>
9905** The new change is ignored. This case does not occur if the new
9906** changeset was recorded immediately after the changesets already
9907** added to the changegroup.
9908** </table>
9909**
9910** If the new changeset contains changes to a table that is already present
9911** in the changegroup, then the number of columns and the position of the
9912** primary key columns for the table must be consistent. If this is not the
9913** case, this function fails with SQLITE_SCHEMA. If the input changeset
9914** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is
9915** returned. Or, if an out-of-memory condition occurs during processing, this
9916** function returns SQLITE_NOMEM. In all cases, if an error occurs the
9917** final contents of the changegroup is undefined.
9918**
9919** If no error occurs, SQLITE_OK is returned.
9920*/
9921SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData);
9922
9923/*
9924** CAPI3REF: Obtain A Composite Changeset From A Changegroup
9925** METHOD: sqlite3_changegroup
9926**
9927** Obtain a buffer containing a changeset (or patchset) representing the
9928** current contents of the changegroup. If the inputs to the changegroup
9929** were themselves changesets, the output is a changeset. Or, if the
9930** inputs were patchsets, the output is also a patchset.
9931**
9932** As with the output of the sqlite3session_changeset() and
9933** sqlite3session_patchset() functions, all changes related to a single
9934** table are grouped together in the output of this function. Tables appear
9935** in the same order as for the very first changeset added to the changegroup.
9936** If the second or subsequent changesets added to the changegroup contain
9937** changes for tables that do not appear in the first changeset, they are
9938** appended onto the end of the output changeset, again in the order in
9939** which they are first encountered.
9940**
9941** If an error occurs, an SQLite error code is returned and the output
9942** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK
9943** is returned and the output variables are set to the size of and a
9944** pointer to the output buffer, respectively. In this case it is the
9945** responsibility of the caller to eventually free the buffer using a
9946** call to sqlite3_free().
9947*/
9948SQLITE_API int sqlite3changegroup_output(
9949 sqlite3_changegroup*,
9950 int *pnData, /* OUT: Size of output buffer in bytes */
9951 void **ppData /* OUT: Pointer to output buffer */
9952);
9953
9954/*
9955** CAPI3REF: Delete A Changegroup Object
9956** DESTRUCTOR: sqlite3_changegroup
9957*/
9958SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*);
9959
9960/*
9961** CAPI3REF: Apply A Changeset To A Database
9962**
9963** Apply a changeset or patchset to a database. These functions attempt to
9964** update the "main" database attached to handle db with the changes found in
9965** the changeset passed via the second and third arguments.
9966**
9967** The fourth argument (xFilter) passed to these functions is the "filter
9968** callback". If it is not NULL, then for each table affected by at least one
9969** change in the changeset, the filter callback is invoked with
9970** the table name as the second argument, and a copy of the context pointer
9971** passed as the sixth argument as the first. If the "filter callback"
9972** returns zero, then no attempt is made to apply any changes to the table.
9973** Otherwise, if the return value is non-zero or the xFilter argument to
9974** is NULL, all changes related to the table are attempted.
9975**
9976** For each table that is not excluded by the filter callback, this function
9977** tests that the target database contains a compatible table. A table is
9978** considered compatible if all of the following are true:
9979**
9980** <ul>
9981** <li> The table has the same name as the name recorded in the
9982** changeset, and
9983** <li> The table has at least as many columns as recorded in the
9984** changeset, and
9985** <li> The table has primary key columns in the same position as
9986** recorded in the changeset.
9987** </ul>
9988**
9989** If there is no compatible table, it is not an error, but none of the
9990** changes associated with the table are applied. A warning message is issued
9991** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most
9992** one such warning is issued for each table in the changeset.
9993**
9994** For each change for which there is a compatible table, an attempt is made
9995** to modify the table contents according to the UPDATE, INSERT or DELETE
9996** change. If a change cannot be applied cleanly, the conflict handler
9997** function passed as the fifth argument to sqlite3changeset_apply() may be
9998** invoked. A description of exactly when the conflict handler is invoked for
9999** each type of change is below.
10000**
10001** Unlike the xFilter argument, xConflict may not be passed NULL. The results
10002** of passing anything other than a valid function pointer as the xConflict
10003** argument are undefined.
10004**
10005** Each time the conflict handler function is invoked, it must return one
10006** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or
10007** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned
10008** if the second argument passed to the conflict handler is either
10009** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler
10010** returns an illegal value, any changes already made are rolled back and
10011** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different
10012** actions are taken by sqlite3changeset_apply() depending on the value
10013** returned by each invocation of the conflict-handler function. Refer to
10014** the documentation for the three
10015** [SQLITE_CHANGESET_OMIT|available return values] for details.
10016**
10017** <dl>
10018** <dt>DELETE Changes<dd>
10019** For each DELETE change, the function checks if the target database
10020** contains a row with the same primary key value (or values) as the
10021** original row values stored in the changeset. If it does, and the values
10022** stored in all non-primary key columns also match the values stored in
10023** the changeset the row is deleted from the target database.
10024**
10025** If a row with matching primary key values is found, but one or more of
10026** the non-primary key fields contains a value different from the original
10027** row value stored in the changeset, the conflict-handler function is
10028** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the
10029** database table has more columns than are recorded in the changeset,
10030** only the values of those non-primary key fields are compared against
10031** the current database contents - any trailing database table columns
10032** are ignored.
10033**
10034** If no row with matching primary key values is found in the database,
10035** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
10036** passed as the second argument.
10037**
10038** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT
10039** (which can only happen if a foreign key constraint is violated), the
10040** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT]
10041** passed as the second argument. This includes the case where the DELETE
10042** operation is attempted because an earlier call to the conflict handler
10043** function returned [SQLITE_CHANGESET_REPLACE].
10044**
10045** <dt>INSERT Changes<dd>
10046** For each INSERT change, an attempt is made to insert the new row into
10047** the database. If the changeset row contains fewer fields than the
10048** database table, the trailing fields are populated with their default
10049** values.
10050**
10051** If the attempt to insert the row fails because the database already
10052** contains a row with the same primary key values, the conflict handler
10053** function is invoked with the second argument set to
10054** [SQLITE_CHANGESET_CONFLICT].
10055**
10056** If the attempt to insert the row fails because of some other constraint
10057** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is
10058** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT].
10059** This includes the case where the INSERT operation is re-attempted because
10060** an earlier call to the conflict handler function returned
10061** [SQLITE_CHANGESET_REPLACE].
10062**
10063** <dt>UPDATE Changes<dd>
10064** For each UPDATE change, the function checks if the target database
10065** contains a row with the same primary key value (or values) as the
10066** original row values stored in the changeset. If it does, and the values
10067** stored in all modified non-primary key columns also match the values
10068** stored in the changeset the row is updated within the target database.
10069**
10070** If a row with matching primary key values is found, but one or more of
10071** the modified non-primary key fields contains a value different from an
10072** original row value stored in the changeset, the conflict-handler function
10073** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since
10074** UPDATE changes only contain values for non-primary key fields that are
10075** to be modified, only those fields need to match the original values to
10076** avoid the SQLITE_CHANGESET_DATA conflict-handler callback.
10077**
10078** If no row with matching primary key values is found in the database,
10079** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
10080** passed as the second argument.
10081**
10082** If the UPDATE operation is attempted, but SQLite returns
10083** SQLITE_CONSTRAINT, the conflict-handler function is invoked with
10084** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument.
10085** This includes the case where the UPDATE operation is attempted after
10086** an earlier call to the conflict handler function returned
10087** [SQLITE_CHANGESET_REPLACE].
10088** </dl>
10089**
10090** It is safe to execute SQL statements, including those that write to the
10091** table that the callback related to, from within the xConflict callback.
10092** This can be used to further customize the applications conflict
10093** resolution strategy.
10094**
10095** All changes made by these functions are enclosed in a savepoint transaction.
10096** If any other error (aside from a constraint failure when attempting to
10097** write to the target database) occurs, then the savepoint transaction is
10098** rolled back, restoring the target database to its original state, and an
10099** SQLite error code returned.
10100**
10101** If the output parameters (ppRebase) and (pnRebase) are non-NULL and
10102** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2()
10103** may set (*ppRebase) to point to a "rebase" that may be used with the
10104** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase)
10105** is set to the size of the buffer in bytes. It is the responsibility of the
10106** caller to eventually free any such buffer using sqlite3_free(). The buffer
10107** is only allocated and populated if one or more conflicts were encountered
10108** while applying the patchset. See comments surrounding the sqlite3_rebaser
10109** APIs for further details.
10110*/
10111SQLITE_API int sqlite3changeset_apply(
10112 sqlite3 *db, /* Apply change to "main" db of this handle */
10113 int nChangeset, /* Size of changeset in bytes */
10114 void *pChangeset, /* Changeset blob */
10115 int(*xFilter)(
10116 void *pCtx, /* Copy of sixth arg to _apply() */
10117 const char *zTab /* Table name */
10118 ),
10119 int(*xConflict)(
10120 void *pCtx, /* Copy of sixth arg to _apply() */
10121 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
10122 sqlite3_changeset_iter *p /* Handle describing change and conflict */
10123 ),
10124 void *pCtx /* First argument passed to xConflict */
10125);
10126SQLITE_API int sqlite3changeset_apply_v2(
10127 sqlite3 *db, /* Apply change to "main" db of this handle */
10128 int nChangeset, /* Size of changeset in bytes */
10129 void *pChangeset, /* Changeset blob */
10130 int(*xFilter)(
10131 void *pCtx, /* Copy of sixth arg to _apply() */
10132 const char *zTab /* Table name */
10133 ),
10134 int(*xConflict)(
10135 void *pCtx, /* Copy of sixth arg to _apply() */
10136 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
10137 sqlite3_changeset_iter *p /* Handle describing change and conflict */
10138 ),
10139 void *pCtx, /* First argument passed to xConflict */
10140 void **ppRebase, int *pnRebase
10141);
10142
10143/*
10144** CAPI3REF: Constants Passed To The Conflict Handler
10145**
10146** Values that may be passed as the second argument to a conflict-handler.
10147**
10148** <dl>
10149** <dt>SQLITE_CHANGESET_DATA<dd>
10150** The conflict handler is invoked with CHANGESET_DATA as the second argument
10151** when processing a DELETE or UPDATE change if a row with the required
10152** PRIMARY KEY fields is present in the database, but one or more other
10153** (non primary-key) fields modified by the update do not contain the
10154** expected "before" values.
10155**
10156** The conflicting row, in this case, is the database row with the matching
10157** primary key.
10158**
10159** <dt>SQLITE_CHANGESET_NOTFOUND<dd>
10160** The conflict handler is invoked with CHANGESET_NOTFOUND as the second
10161** argument when processing a DELETE or UPDATE change if a row with the
10162** required PRIMARY KEY fields is not present in the database.
10163**
10164** There is no conflicting row in this case. The results of invoking the
10165** sqlite3changeset_conflict() API are undefined.
10166**
10167** <dt>SQLITE_CHANGESET_CONFLICT<dd>
10168** CHANGESET_CONFLICT is passed as the second argument to the conflict
10169** handler while processing an INSERT change if the operation would result
10170** in duplicate primary key values.
10171**
10172** The conflicting row in this case is the database row with the matching
10173** primary key.
10174**
10175** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd>
10176** If foreign key handling is enabled, and applying a changeset leaves the
10177** database in a state containing foreign key violations, the conflict
10178** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument
10179** exactly once before the changeset is committed. If the conflict handler
10180** returns CHANGESET_OMIT, the changes, including those that caused the
10181** foreign key constraint violation, are committed. Or, if it returns
10182** CHANGESET_ABORT, the changeset is rolled back.
10183**
10184** No current or conflicting row information is provided. The only function
10185** it is possible to call on the supplied sqlite3_changeset_iter handle
10186** is sqlite3changeset_fk_conflicts().
10187**
10188** <dt>SQLITE_CHANGESET_CONSTRAINT<dd>
10189** If any other constraint violation occurs while applying a change (i.e.
10190** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is
10191** invoked with CHANGESET_CONSTRAINT as the second argument.
10192**
10193** There is no conflicting row in this case. The results of invoking the
10194** sqlite3changeset_conflict() API are undefined.
10195**
10196** </dl>
10197*/
10198#define SQLITE_CHANGESET_DATA 1
10199#define SQLITE_CHANGESET_NOTFOUND 2
10200#define SQLITE_CHANGESET_CONFLICT 3
10201#define SQLITE_CHANGESET_CONSTRAINT 4
10202#define SQLITE_CHANGESET_FOREIGN_KEY 5
10203
10204/*
10205** CAPI3REF: Constants Returned By The Conflict Handler
10206**
10207** A conflict handler callback must return one of the following three values.
10208**
10209** <dl>
10210** <dt>SQLITE_CHANGESET_OMIT<dd>
10211** If a conflict handler returns this value no special action is taken. The
10212** change that caused the conflict is not applied. The session module
10213** continues to the next change in the changeset.
10214**
10215** <dt>SQLITE_CHANGESET_REPLACE<dd>
10216** This value may only be returned if the second argument to the conflict
10217** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this
10218** is not the case, any changes applied so far are rolled back and the
10219** call to sqlite3changeset_apply() returns SQLITE_MISUSE.
10220**
10221** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict
10222** handler, then the conflicting row is either updated or deleted, depending
10223** on the type of change.
10224**
10225** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict
10226** handler, then the conflicting row is removed from the database and a
10227** second attempt to apply the change is made. If this second attempt fails,
10228** the original row is restored to the database before continuing.
10229**
10230** <dt>SQLITE_CHANGESET_ABORT<dd>
10231** If this value is returned, any changes applied so far are rolled back
10232** and the call to sqlite3changeset_apply() returns SQLITE_ABORT.
10233** </dl>
10234*/
10235#define SQLITE_CHANGESET_OMIT 0
10236#define SQLITE_CHANGESET_REPLACE 1
10237#define SQLITE_CHANGESET_ABORT 2
10238
10239/*
10240** CAPI3REF: Rebasing changesets
10241** EXPERIMENTAL
10242**
10243** Suppose there is a site hosting a database in state S0. And that
10244** modifications are made that move that database to state S1 and a
10245** changeset recorded (the "local" changeset). Then, a changeset based
10246** on S0 is received from another site (the "remote" changeset) and
10247** applied to the database. The database is then in state
10248** (S1+"remote"), where the exact state depends on any conflict
10249** resolution decisions (OMIT or REPLACE) made while applying "remote".
10250** Rebasing a changeset is to update it to take those conflict
10251** resolution decisions into account, so that the same conflicts
10252** do not have to be resolved elsewhere in the network.
10253**
10254** For example, if both the local and remote changesets contain an
10255** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)":
10256**
10257** local: INSERT INTO t1 VALUES(1, 'v1');
10258** remote: INSERT INTO t1 VALUES(1, 'v2');
10259**
10260** and the conflict resolution is REPLACE, then the INSERT change is
10261** removed from the local changeset (it was overridden). Or, if the
10262** conflict resolution was "OMIT", then the local changeset is modified
10263** to instead contain:
10264**
10265** UPDATE t1 SET b = 'v2' WHERE a=1;
10266**
10267** Changes within the local changeset are rebased as follows:
10268**
10269** <dl>
10270** <dt>Local INSERT<dd>
10271** This may only conflict with a remote INSERT. If the conflict
10272** resolution was OMIT, then add an UPDATE change to the rebased
10273** changeset. Or, if the conflict resolution was REPLACE, add
10274** nothing to the rebased changeset.
10275**
10276** <dt>Local DELETE<dd>
10277** This may conflict with a remote UPDATE or DELETE. In both cases the
10278** only possible resolution is OMIT. If the remote operation was a
10279** DELETE, then add no change to the rebased changeset. If the remote
10280** operation was an UPDATE, then the old.* fields of change are updated
10281** to reflect the new.* values in the UPDATE.
10282**
10283** <dt>Local UPDATE<dd>
10284** This may conflict with a remote UPDATE or DELETE. If it conflicts
10285** with a DELETE, and the conflict resolution was OMIT, then the update
10286** is changed into an INSERT. Any undefined values in the new.* record
10287** from the update change are filled in using the old.* values from
10288** the conflicting DELETE. Or, if the conflict resolution was REPLACE,
10289** the UPDATE change is simply omitted from the rebased changeset.
10290**
10291** If conflict is with a remote UPDATE and the resolution is OMIT, then
10292** the old.* values are rebased using the new.* values in the remote
10293** change. Or, if the resolution is REPLACE, then the change is copied
10294** into the rebased changeset with updates to columns also updated by
10295** the conflicting remote UPDATE removed. If this means no columns would
10296** be updated, the change is omitted.
10297** </dl>
10298**
10299** A local change may be rebased against multiple remote changes
10300** simultaneously. If a single key is modified by multiple remote
10301** changesets, they are combined as follows before the local changeset
10302** is rebased:
10303**
10304** <ul>
10305** <li> If there has been one or more REPLACE resolutions on a
10306** key, it is rebased according to a REPLACE.
10307**
10308** <li> If there have been no REPLACE resolutions on a key, then
10309** the local changeset is rebased according to the most recent
10310** of the OMIT resolutions.
10311** </ul>
10312**
10313** Note that conflict resolutions from multiple remote changesets are
10314** combined on a per-field basis, not per-row. This means that in the
10315** case of multiple remote UPDATE operations, some fields of a single
10316** local change may be rebased for REPLACE while others are rebased for
10317** OMIT.
10318**
10319** In order to rebase a local changeset, the remote changeset must first
10320** be applied to the local database using sqlite3changeset_apply_v2() and
10321** the buffer of rebase information captured. Then:
10322**
10323** <ol>
10324** <li> An sqlite3_rebaser object is created by calling
10325** sqlite3rebaser_create().
10326** <li> The new object is configured with the rebase buffer obtained from
10327** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure().
10328** If the local changeset is to be rebased against multiple remote
10329** changesets, then sqlite3rebaser_configure() should be called
10330** multiple times, in the same order that the multiple
10331** sqlite3changeset_apply_v2() calls were made.
10332** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase().
10333** <li> The sqlite3_rebaser object is deleted by calling
10334** sqlite3rebaser_delete().
10335** </ol>
10336*/
10337typedef struct sqlite3_rebaser sqlite3_rebaser;
10338
10339/*
10340** CAPI3REF: Create a changeset rebaser object.
10341** EXPERIMENTAL
10342**
10343** Allocate a new changeset rebaser object. If successful, set (*ppNew) to
10344** point to the new object and return SQLITE_OK. Otherwise, if an error
10345** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew)
10346** to NULL.
10347*/
10348SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew);
10349
10350/*
10351** CAPI3REF: Configure a changeset rebaser object.
10352** EXPERIMENTAL
10353**
10354** Configure the changeset rebaser object to rebase changesets according
10355** to the conflict resolutions described by buffer pRebase (size nRebase
10356** bytes), which must have been obtained from a previous call to
10357** sqlite3changeset_apply_v2().
10358*/
10359SQLITE_API int sqlite3rebaser_configure(
10360 sqlite3_rebaser*,
10361 int nRebase, const void *pRebase
10362);
10363
10364/*
10365** CAPI3REF: Rebase a changeset
10366** EXPERIMENTAL
10367**
10368** Argument pIn must point to a buffer containing a changeset nIn bytes
10369** in size. This function allocates and populates a buffer with a copy
10370** of the changeset rebased rebased according to the configuration of the
10371** rebaser object passed as the first argument. If successful, (*ppOut)
10372** is set to point to the new buffer containing the rebased changset and
10373** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the
10374** responsibility of the caller to eventually free the new buffer using
10375** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut)
10376** are set to zero and an SQLite error code returned.
10377*/
10378SQLITE_API int sqlite3rebaser_rebase(
10379 sqlite3_rebaser*,
10380 int nIn, const void *pIn,
10381 int *pnOut, void **ppOut
10382);
10383
10384/*
10385** CAPI3REF: Delete a changeset rebaser object.
10386** EXPERIMENTAL
10387**
10388** Delete the changeset rebaser object and all associated resources. There
10389** should be one call to this function for each successful invocation
10390** of sqlite3rebaser_create().
10391*/
10392SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p);
10393
10394/*
10395** CAPI3REF: Streaming Versions of API functions.
10396**
10397** The six streaming API xxx_strm() functions serve similar purposes to the
10398** corresponding non-streaming API functions:
10399**
10400** <table border=1 style="margin-left:8ex;margin-right:8ex">
10401** <tr><th>Streaming function<th>Non-streaming equivalent</th>
10402** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply]
10403** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat]
10404** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert]
10405** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start]
10406** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset]
10407** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset]
10408** </table>
10409**
10410** Non-streaming functions that accept changesets (or patchsets) as input
10411** require that the entire changeset be stored in a single buffer in memory.
10412** Similarly, those that return a changeset or patchset do so by returning
10413** a pointer to a single large buffer allocated using sqlite3_malloc().
10414** Normally this is convenient. However, if an application running in a
10415** low-memory environment is required to handle very large changesets, the
10416** large contiguous memory allocations required can become onerous.
10417**
10418** In order to avoid this problem, instead of a single large buffer, input
10419** is passed to a streaming API functions by way of a callback function that
10420** the sessions module invokes to incrementally request input data as it is
10421** required. In all cases, a pair of API function parameters such as
10422**
10423** <pre>
10424** &nbsp; int nChangeset,
10425** &nbsp; void *pChangeset,
10426** </pre>
10427**
10428** Is replaced by:
10429**
10430** <pre>
10431** &nbsp; int (*xInput)(void *pIn, void *pData, int *pnData),
10432** &nbsp; void *pIn,
10433** </pre>
10434**
10435** Each time the xInput callback is invoked by the sessions module, the first
10436** argument passed is a copy of the supplied pIn context pointer. The second
10437** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no
10438** error occurs the xInput method should copy up to (*pnData) bytes of data
10439** into the buffer and set (*pnData) to the actual number of bytes copied
10440** before returning SQLITE_OK. If the input is completely exhausted, (*pnData)
10441** should be set to zero to indicate this. Or, if an error occurs, an SQLite
10442** error code should be returned. In all cases, if an xInput callback returns
10443** an error, all processing is abandoned and the streaming API function
10444** returns a copy of the error code to the caller.
10445**
10446** In the case of sqlite3changeset_start_strm(), the xInput callback may be
10447** invoked by the sessions module at any point during the lifetime of the
10448** iterator. If such an xInput callback returns an error, the iterator enters
10449** an error state, whereby all subsequent calls to iterator functions
10450** immediately fail with the same error code as returned by xInput.
10451**
10452** Similarly, streaming API functions that return changesets (or patchsets)
10453** return them in chunks by way of a callback function instead of via a
10454** pointer to a single large buffer. In this case, a pair of parameters such
10455** as:
10456**
10457** <pre>
10458** &nbsp; int *pnChangeset,
10459** &nbsp; void **ppChangeset,
10460** </pre>
10461**
10462** Is replaced by:
10463**
10464** <pre>
10465** &nbsp; int (*xOutput)(void *pOut, const void *pData, int nData),
10466** &nbsp; void *pOut
10467** </pre>
10468**
10469** The xOutput callback is invoked zero or more times to return data to
10470** the application. The first parameter passed to each call is a copy of the
10471** pOut pointer supplied by the application. The second parameter, pData,
10472** points to a buffer nData bytes in size containing the chunk of output
10473** data being returned. If the xOutput callback successfully processes the
10474** supplied data, it should return SQLITE_OK to indicate success. Otherwise,
10475** it should return some other SQLite error code. In this case processing
10476** is immediately abandoned and the streaming API function returns a copy
10477** of the xOutput error code to the application.
10478**
10479** The sessions module never invokes an xOutput callback with the third
10480** parameter set to a value less than or equal to zero. Other than this,
10481** no guarantees are made as to the size of the chunks of data returned.
10482*/
10483SQLITE_API int sqlite3changeset_apply_strm(
10484 sqlite3 *db, /* Apply change to "main" db of this handle */
10485 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
10486 void *pIn, /* First arg for xInput */
10487 int(*xFilter)(
10488 void *pCtx, /* Copy of sixth arg to _apply() */
10489 const char *zTab /* Table name */
10490 ),
10491 int(*xConflict)(
10492 void *pCtx, /* Copy of sixth arg to _apply() */
10493 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
10494 sqlite3_changeset_iter *p /* Handle describing change and conflict */
10495 ),
10496 void *pCtx /* First argument passed to xConflict */
10497);
10498SQLITE_API int sqlite3changeset_apply_v2_strm(
10499 sqlite3 *db, /* Apply change to "main" db of this handle */
10500 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
10501 void *pIn, /* First arg for xInput */
10502 int(*xFilter)(
10503 void *pCtx, /* Copy of sixth arg to _apply() */
10504 const char *zTab /* Table name */
10505 ),
10506 int(*xConflict)(
10507 void *pCtx, /* Copy of sixth arg to _apply() */
10508 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
10509 sqlite3_changeset_iter *p /* Handle describing change and conflict */
10510 ),
10511 void *pCtx, /* First argument passed to xConflict */
10512 void **ppRebase, int *pnRebase
10513);
10514SQLITE_API int sqlite3changeset_concat_strm(
10515 int (*xInputA)(void *pIn, void *pData, int *pnData),
10516 void *pInA,
10517 int (*xInputB)(void *pIn, void *pData, int *pnData),
10518 void *pInB,
10519 int (*xOutput)(void *pOut, const void *pData, int nData),
10520 void *pOut
10521);
10522SQLITE_API int sqlite3changeset_invert_strm(
10523 int (*xInput)(void *pIn, void *pData, int *pnData),
10524 void *pIn,
10525 int (*xOutput)(void *pOut, const void *pData, int nData),
10526 void *pOut
10527);
10528SQLITE_API int sqlite3changeset_start_strm(
10529 sqlite3_changeset_iter **pp,
10530 int (*xInput)(void *pIn, void *pData, int *pnData),
10531 void *pIn
10532);
10533SQLITE_API int sqlite3session_changeset_strm(
10534 sqlite3_session *pSession,
10535 int (*xOutput)(void *pOut, const void *pData, int nData),
10536 void *pOut
10537);
10538SQLITE_API int sqlite3session_patchset_strm(
10539 sqlite3_session *pSession,
10540 int (*xOutput)(void *pOut, const void *pData, int nData),
10541 void *pOut
10542);
10543SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*,
10544 int (*xInput)(void *pIn, void *pData, int *pnData),
10545 void *pIn
10546);
10547SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*,
10548 int (*xOutput)(void *pOut, const void *pData, int nData),
10549 void *pOut
10550);
10551SQLITE_API int sqlite3rebaser_rebase_strm(
10552 sqlite3_rebaser *pRebaser,
10553 int (*xInput)(void *pIn, void *pData, int *pnData),
10554 void *pIn,
10555 int (*xOutput)(void *pOut, const void *pData, int nData),
10556 void *pOut
10557);
10558
10559
10560/*
10561** Make sure we can call this stuff from C++.
10562*/
10563#ifdef __cplusplus
10564}
10565#endif
10566
10567#endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */
10568
10569/******** End of sqlite3session.h *********/
10570/******** Begin file fts5.h *********/
10571/*
10572** 2014 May 31
10573**
10574** The author disclaims copyright to this source code. In place of
10575** a legal notice, here is a blessing:
10576**
10577** May you do good and not evil.
10578** May you find forgiveness for yourself and forgive others.
10579** May you share freely, never taking more than you give.
10580**
10581******************************************************************************
10582**
10583** Interfaces to extend FTS5. Using the interfaces defined in this file,
10584** FTS5 may be extended with:
10585**
10586** * custom tokenizers, and
10587** * custom auxiliary functions.
10588*/
10589
10590
10591#ifndef _FTS5_H
10592#define _FTS5_H
10593
10594
10595#ifdef __cplusplus
10596extern "C" {
10597#endif
10598
10599/*************************************************************************
10600** CUSTOM AUXILIARY FUNCTIONS
10601**
10602** Virtual table implementations may overload SQL functions by implementing
10603** the sqlite3_module.xFindFunction() method.
10604*/
10605
10606typedef struct Fts5ExtensionApi Fts5ExtensionApi;
10607typedef struct Fts5Context Fts5Context;
10608typedef struct Fts5PhraseIter Fts5PhraseIter;
10609
10610typedef void (*fts5_extension_function)(
10611 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */
10612 Fts5Context *pFts, /* First arg to pass to pApi functions */
10613 sqlite3_context *pCtx, /* Context for returning result/error */
10614 int nVal, /* Number of values in apVal[] array */
10615 sqlite3_value **apVal /* Array of trailing arguments */
10616);
10617
10618struct Fts5PhraseIter {
10619 const unsigned char *a;
10620 const unsigned char *b;
10621};
10622
10623/*
10624** EXTENSION API FUNCTIONS
10625**
10626** xUserData(pFts):
10627** Return a copy of the context pointer the extension function was
10628** registered with.
10629**
10630** xColumnTotalSize(pFts, iCol, pnToken):
10631** If parameter iCol is less than zero, set output variable *pnToken
10632** to the total number of tokens in the FTS5 table. Or, if iCol is
10633** non-negative but less than the number of columns in the table, return
10634** the total number of tokens in column iCol, considering all rows in
10635** the FTS5 table.
10636**
10637** If parameter iCol is greater than or equal to the number of columns
10638** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
10639** an OOM condition or IO error), an appropriate SQLite error code is
10640** returned.
10641**
10642** xColumnCount(pFts):
10643** Return the number of columns in the table.
10644**
10645** xColumnSize(pFts, iCol, pnToken):
10646** If parameter iCol is less than zero, set output variable *pnToken
10647** to the total number of tokens in the current row. Or, if iCol is
10648** non-negative but less than the number of columns in the table, set
10649** *pnToken to the number of tokens in column iCol of the current row.
10650**
10651** If parameter iCol is greater than or equal to the number of columns
10652** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
10653** an OOM condition or IO error), an appropriate SQLite error code is
10654** returned.
10655**
10656** This function may be quite inefficient if used with an FTS5 table
10657** created with the "columnsize=0" option.
10658**
10659** xColumnText:
10660** This function attempts to retrieve the text of column iCol of the
10661** current document. If successful, (*pz) is set to point to a buffer
10662** containing the text in utf-8 encoding, (*pn) is set to the size in bytes
10663** (not characters) of the buffer and SQLITE_OK is returned. Otherwise,
10664** if an error occurs, an SQLite error code is returned and the final values
10665** of (*pz) and (*pn) are undefined.
10666**
10667** xPhraseCount:
10668** Returns the number of phrases in the current query expression.
10669**
10670** xPhraseSize:
10671** Returns the number of tokens in phrase iPhrase of the query. Phrases
10672** are numbered starting from zero.
10673**
10674** xInstCount:
10675** Set *pnInst to the total number of occurrences of all phrases within
10676** the query within the current row. Return SQLITE_OK if successful, or
10677** an error code (i.e. SQLITE_NOMEM) if an error occurs.
10678**
10679** This API can be quite slow if used with an FTS5 table created with the
10680** "detail=none" or "detail=column" option. If the FTS5 table is created
10681** with either "detail=none" or "detail=column" and "content=" option
10682** (i.e. if it is a contentless table), then this API always returns 0.
10683**
10684** xInst:
10685** Query for the details of phrase match iIdx within the current row.
10686** Phrase matches are numbered starting from zero, so the iIdx argument
10687** should be greater than or equal to zero and smaller than the value
10688** output by xInstCount().
10689**
10690** Usually, output parameter *piPhrase is set to the phrase number, *piCol
10691** to the column in which it occurs and *piOff the token offset of the
10692** first token of the phrase. The exception is if the table was created
10693** with the offsets=0 option specified. In this case *piOff is always
10694** set to -1.
10695**
10696** Returns SQLITE_OK if successful, or an error code (i.e. SQLITE_NOMEM)
10697** if an error occurs.
10698**
10699** This API can be quite slow if used with an FTS5 table created with the
10700** "detail=none" or "detail=column" option.
10701**
10702** xRowid:
10703** Returns the rowid of the current row.
10704**
10705** xTokenize:
10706** Tokenize text using the tokenizer belonging to the FTS5 table.
10707**
10708** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback):
10709** This API function is used to query the FTS table for phrase iPhrase
10710** of the current query. Specifically, a query equivalent to:
10711**
10712** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid
10713**
10714** with $p set to a phrase equivalent to the phrase iPhrase of the
10715** current query is executed. Any column filter that applies to
10716** phrase iPhrase of the current query is included in $p. For each
10717** row visited, the callback function passed as the fourth argument
10718** is invoked. The context and API objects passed to the callback
10719** function may be used to access the properties of each matched row.
10720** Invoking Api.xUserData() returns a copy of the pointer passed as
10721** the third argument to pUserData.
10722**
10723** If the callback function returns any value other than SQLITE_OK, the
10724** query is abandoned and the xQueryPhrase function returns immediately.
10725** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK.
10726** Otherwise, the error code is propagated upwards.
10727**
10728** If the query runs to completion without incident, SQLITE_OK is returned.
10729** Or, if some error occurs before the query completes or is aborted by
10730** the callback, an SQLite error code is returned.
10731**
10732**
10733** xSetAuxdata(pFts5, pAux, xDelete)
10734**
10735** Save the pointer passed as the second argument as the extension functions
10736** "auxiliary data". The pointer may then be retrieved by the current or any
10737** future invocation of the same fts5 extension function made as part of
10738** of the same MATCH query using the xGetAuxdata() API.
10739**
10740** Each extension function is allocated a single auxiliary data slot for
10741** each FTS query (MATCH expression). If the extension function is invoked
10742** more than once for a single FTS query, then all invocations share a
10743** single auxiliary data context.
10744**
10745** If there is already an auxiliary data pointer when this function is
10746** invoked, then it is replaced by the new pointer. If an xDelete callback
10747** was specified along with the original pointer, it is invoked at this
10748** point.
10749**
10750** The xDelete callback, if one is specified, is also invoked on the
10751** auxiliary data pointer after the FTS5 query has finished.
10752**
10753** If an error (e.g. an OOM condition) occurs within this function, an
10754** the auxiliary data is set to NULL and an error code returned. If the
10755** xDelete parameter was not NULL, it is invoked on the auxiliary data
10756** pointer before returning.
10757**
10758**
10759** xGetAuxdata(pFts5, bClear)
10760**
10761** Returns the current auxiliary data pointer for the fts5 extension
10762** function. See the xSetAuxdata() method for details.
10763**
10764** If the bClear argument is non-zero, then the auxiliary data is cleared
10765** (set to NULL) before this function returns. In this case the xDelete,
10766** if any, is not invoked.
10767**
10768**
10769** xRowCount(pFts5, pnRow)
10770**
10771** This function is used to retrieve the total number of rows in the table.
10772** In other words, the same value that would be returned by:
10773**
10774** SELECT count(*) FROM ftstable;
10775**
10776** xPhraseFirst()
10777** This function is used, along with type Fts5PhraseIter and the xPhraseNext
10778** method, to iterate through all instances of a single query phrase within
10779** the current row. This is the same information as is accessible via the
10780** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient
10781** to use, this API may be faster under some circumstances. To iterate
10782** through instances of phrase iPhrase, use the following code:
10783**
10784** Fts5PhraseIter iter;
10785** int iCol, iOff;
10786** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff);
10787** iCol>=0;
10788** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff)
10789** ){
10790** // An instance of phrase iPhrase at offset iOff of column iCol
10791** }
10792**
10793** The Fts5PhraseIter structure is defined above. Applications should not
10794** modify this structure directly - it should only be used as shown above
10795** with the xPhraseFirst() and xPhraseNext() API methods (and by
10796** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below).
10797**
10798** This API can be quite slow if used with an FTS5 table created with the
10799** "detail=none" or "detail=column" option. If the FTS5 table is created
10800** with either "detail=none" or "detail=column" and "content=" option
10801** (i.e. if it is a contentless table), then this API always iterates
10802** through an empty set (all calls to xPhraseFirst() set iCol to -1).
10803**
10804** xPhraseNext()
10805** See xPhraseFirst above.
10806**
10807** xPhraseFirstColumn()
10808** This function and xPhraseNextColumn() are similar to the xPhraseFirst()
10809** and xPhraseNext() APIs described above. The difference is that instead
10810** of iterating through all instances of a phrase in the current row, these
10811** APIs are used to iterate through the set of columns in the current row
10812** that contain one or more instances of a specified phrase. For example:
10813**
10814** Fts5PhraseIter iter;
10815** int iCol;
10816** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol);
10817** iCol>=0;
10818** pApi->xPhraseNextColumn(pFts, &iter, &iCol)
10819** ){
10820** // Column iCol contains at least one instance of phrase iPhrase
10821** }
10822**
10823** This API can be quite slow if used with an FTS5 table created with the
10824** "detail=none" option. If the FTS5 table is created with either
10825** "detail=none" "content=" option (i.e. if it is a contentless table),
10826** then this API always iterates through an empty set (all calls to
10827** xPhraseFirstColumn() set iCol to -1).
10828**
10829** The information accessed using this API and its companion
10830** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext
10831** (or xInst/xInstCount). The chief advantage of this API is that it is
10832** significantly more efficient than those alternatives when used with
10833** "detail=column" tables.
10834**
10835** xPhraseNextColumn()
10836** See xPhraseFirstColumn above.
10837*/
10838struct Fts5ExtensionApi {
10839 int iVersion; /* Currently always set to 3 */
10840
10841 void *(*xUserData)(Fts5Context*);
10842
10843 int (*xColumnCount)(Fts5Context*);
10844 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow);
10845 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken);
10846
10847 int (*xTokenize)(Fts5Context*,
10848 const char *pText, int nText, /* Text to tokenize */
10849 void *pCtx, /* Context passed to xToken() */
10850 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */
10851 );
10852
10853 int (*xPhraseCount)(Fts5Context*);
10854 int (*xPhraseSize)(Fts5Context*, int iPhrase);
10855
10856 int (*xInstCount)(Fts5Context*, int *pnInst);
10857 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff);
10858
10859 sqlite3_int64 (*xRowid)(Fts5Context*);
10860 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn);
10861 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken);
10862
10863 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData,
10864 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*)
10865 );
10866 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*));
10867 void *(*xGetAuxdata)(Fts5Context*, int bClear);
10868
10869 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*);
10870 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff);
10871
10872 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*);
10873 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol);
10874};
10875
10876/*
10877** CUSTOM AUXILIARY FUNCTIONS
10878*************************************************************************/
10879
10880/*************************************************************************
10881** CUSTOM TOKENIZERS
10882**
10883** Applications may also register custom tokenizer types. A tokenizer
10884** is registered by providing fts5 with a populated instance of the
10885** following structure. All structure methods must be defined, setting
10886** any member of the fts5_tokenizer struct to NULL leads to undefined
10887** behaviour. The structure methods are expected to function as follows:
10888**
10889** xCreate:
10890** This function is used to allocate and initialize a tokenizer instance.
10891** A tokenizer instance is required to actually tokenize text.
10892**
10893** The first argument passed to this function is a copy of the (void*)
10894** pointer provided by the application when the fts5_tokenizer object
10895** was registered with FTS5 (the third argument to xCreateTokenizer()).
10896** The second and third arguments are an array of nul-terminated strings
10897** containing the tokenizer arguments, if any, specified following the
10898** tokenizer name as part of the CREATE VIRTUAL TABLE statement used
10899** to create the FTS5 table.
10900**
10901** The final argument is an output variable. If successful, (*ppOut)
10902** should be set to point to the new tokenizer handle and SQLITE_OK
10903** returned. If an error occurs, some value other than SQLITE_OK should
10904** be returned. In this case, fts5 assumes that the final value of *ppOut
10905** is undefined.
10906**
10907** xDelete:
10908** This function is invoked to delete a tokenizer handle previously
10909** allocated using xCreate(). Fts5 guarantees that this function will
10910** be invoked exactly once for each successful call to xCreate().
10911**
10912** xTokenize:
10913** This function is expected to tokenize the nText byte string indicated
10914** by argument pText. pText may or may not be nul-terminated. The first
10915** argument passed to this function is a pointer to an Fts5Tokenizer object
10916** returned by an earlier call to xCreate().
10917**
10918** The second argument indicates the reason that FTS5 is requesting
10919** tokenization of the supplied text. This is always one of the following
10920** four values:
10921**
10922** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into
10923** or removed from the FTS table. The tokenizer is being invoked to
10924** determine the set of tokens to add to (or delete from) the
10925** FTS index.
10926**
10927** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed
10928** against the FTS index. The tokenizer is being called to tokenize
10929** a bareword or quoted string specified as part of the query.
10930**
10931** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as
10932** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is
10933** followed by a "*" character, indicating that the last token
10934** returned by the tokenizer will be treated as a token prefix.
10935**
10936** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to
10937** satisfy an fts5_api.xTokenize() request made by an auxiliary
10938** function. Or an fts5_api.xColumnSize() request made by the same
10939** on a columnsize=0 database.
10940** </ul>
10941**
10942** For each token in the input string, the supplied callback xToken() must
10943** be invoked. The first argument to it should be a copy of the pointer
10944** passed as the second argument to xTokenize(). The third and fourth
10945** arguments are a pointer to a buffer containing the token text, and the
10946** size of the token in bytes. The 4th and 5th arguments are the byte offsets
10947** of the first byte of and first byte immediately following the text from
10948** which the token is derived within the input.
10949**
10950** The second argument passed to the xToken() callback ("tflags") should
10951** normally be set to 0. The exception is if the tokenizer supports
10952** synonyms. In this case see the discussion below for details.
10953**
10954** FTS5 assumes the xToken() callback is invoked for each token in the
10955** order that they occur within the input text.
10956**
10957** If an xToken() callback returns any value other than SQLITE_OK, then
10958** the tokenization should be abandoned and the xTokenize() method should
10959** immediately return a copy of the xToken() return value. Or, if the
10960** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally,
10961** if an error occurs with the xTokenize() implementation itself, it
10962** may abandon the tokenization and return any error code other than
10963** SQLITE_OK or SQLITE_DONE.
10964**
10965** SYNONYM SUPPORT
10966**
10967** Custom tokenizers may also support synonyms. Consider a case in which a
10968** user wishes to query for a phrase such as "first place". Using the
10969** built-in tokenizers, the FTS5 query 'first + place' will match instances
10970** of "first place" within the document set, but not alternative forms
10971** such as "1st place". In some applications, it would be better to match
10972** all instances of "first place" or "1st place" regardless of which form
10973** the user specified in the MATCH query text.
10974**
10975** There are several ways to approach this in FTS5:
10976**
10977** <ol><li> By mapping all synonyms to a single token. In this case, the
10978** In the above example, this means that the tokenizer returns the
10979** same token for inputs "first" and "1st". Say that token is in
10980** fact "first", so that when the user inserts the document "I won
10981** 1st place" entries are added to the index for tokens "i", "won",
10982** "first" and "place". If the user then queries for '1st + place',
10983** the tokenizer substitutes "first" for "1st" and the query works
10984** as expected.
10985**
10986** <li> By adding multiple synonyms for a single term to the FTS index.
10987** In this case, when tokenizing query text, the tokenizer may
10988** provide multiple synonyms for a single term within the document.
10989** FTS5 then queries the index for each synonym individually. For
10990** example, faced with the query:
10991**
10992** <codeblock>
10993** ... MATCH 'first place'</codeblock>
10994**
10995** the tokenizer offers both "1st" and "first" as synonyms for the
10996** first token in the MATCH query and FTS5 effectively runs a query
10997** similar to:
10998**
10999** <codeblock>
11000** ... MATCH '(first OR 1st) place'</codeblock>
11001**
11002** except that, for the purposes of auxiliary functions, the query
11003** still appears to contain just two phrases - "(first OR 1st)"
11004** being treated as a single phrase.
11005**
11006** <li> By adding multiple synonyms for a single term to the FTS index.
11007** Using this method, when tokenizing document text, the tokenizer
11008** provides multiple synonyms for each token. So that when a
11009** document such as "I won first place" is tokenized, entries are
11010** added to the FTS index for "i", "won", "first", "1st" and
11011** "place".
11012**
11013** This way, even if the tokenizer does not provide synonyms
11014** when tokenizing query text (it should not - to do would be
11015** inefficient), it doesn't matter if the user queries for
11016** 'first + place' or '1st + place', as there are entires in the
11017** FTS index corresponding to both forms of the first token.
11018** </ol>
11019**
11020** Whether it is parsing document or query text, any call to xToken that
11021** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit
11022** is considered to supply a synonym for the previous token. For example,
11023** when parsing the document "I won first place", a tokenizer that supports
11024** synonyms would call xToken() 5 times, as follows:
11025**
11026** <codeblock>
11027** xToken(pCtx, 0, "i", 1, 0, 1);
11028** xToken(pCtx, 0, "won", 3, 2, 5);
11029** xToken(pCtx, 0, "first", 5, 6, 11);
11030** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11);
11031** xToken(pCtx, 0, "place", 5, 12, 17);
11032**</codeblock>
11033**
11034** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time
11035** xToken() is called. Multiple synonyms may be specified for a single token
11036** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence.
11037** There is no limit to the number of synonyms that may be provided for a
11038** single token.
11039**
11040** In many cases, method (1) above is the best approach. It does not add
11041** extra data to the FTS index or require FTS5 to query for multiple terms,
11042** so it is efficient in terms of disk space and query speed. However, it
11043** does not support prefix queries very well. If, as suggested above, the
11044** token "first" is subsituted for "1st" by the tokenizer, then the query:
11045**
11046** <codeblock>
11047** ... MATCH '1s*'</codeblock>
11048**
11049** will not match documents that contain the token "1st" (as the tokenizer
11050** will probably not map "1s" to any prefix of "first").
11051**
11052** For full prefix support, method (3) may be preferred. In this case,
11053** because the index contains entries for both "first" and "1st", prefix
11054** queries such as 'fi*' or '1s*' will match correctly. However, because
11055** extra entries are added to the FTS index, this method uses more space
11056** within the database.
11057**
11058** Method (2) offers a midpoint between (1) and (3). Using this method,
11059** a query such as '1s*' will match documents that contain the literal
11060** token "1st", but not "first" (assuming the tokenizer is not able to
11061** provide synonyms for prefixes). However, a non-prefix query like '1st'
11062** will match against "1st" and "first". This method does not require
11063** extra disk space, as no extra entries are added to the FTS index.
11064** On the other hand, it may require more CPU cycles to run MATCH queries,
11065** as separate queries of the FTS index are required for each synonym.
11066**
11067** When using methods (2) or (3), it is important that the tokenizer only
11068** provide synonyms when tokenizing document text (method (2)) or query
11069** text (method (3)), not both. Doing so will not cause any errors, but is
11070** inefficient.
11071*/
11072typedef struct Fts5Tokenizer Fts5Tokenizer;
11073typedef struct fts5_tokenizer fts5_tokenizer;
11074struct fts5_tokenizer {
11075 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
11076 void (*xDelete)(Fts5Tokenizer*);
11077 int (*xTokenize)(Fts5Tokenizer*,
11078 void *pCtx,
11079 int flags, /* Mask of FTS5_TOKENIZE_* flags */
11080 const char *pText, int nText,
11081 int (*xToken)(
11082 void *pCtx, /* Copy of 2nd argument to xTokenize() */
11083 int tflags, /* Mask of FTS5_TOKEN_* flags */
11084 const char *pToken, /* Pointer to buffer containing token */
11085 int nToken, /* Size of token in bytes */
11086 int iStart, /* Byte offset of token within input text */
11087 int iEnd /* Byte offset of end of token within input text */
11088 )
11089 );
11090};
11091
11092/* Flags that may be passed as the third argument to xTokenize() */
11093#define FTS5_TOKENIZE_QUERY 0x0001
11094#define FTS5_TOKENIZE_PREFIX 0x0002
11095#define FTS5_TOKENIZE_DOCUMENT 0x0004
11096#define FTS5_TOKENIZE_AUX 0x0008
11097
11098/* Flags that may be passed by the tokenizer implementation back to FTS5
11099** as the third argument to the supplied xToken callback. */
11100#define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */
11101
11102/*
11103** END OF CUSTOM TOKENIZERS
11104*************************************************************************/
11105
11106/*************************************************************************
11107** FTS5 EXTENSION REGISTRATION API
11108*/
11109typedef struct fts5_api fts5_api;
11110struct fts5_api {
11111 int iVersion; /* Currently always set to 2 */
11112
11113 /* Create a new tokenizer */
11114 int (*xCreateTokenizer)(
11115 fts5_api *pApi,
11116 const char *zName,
11117 void *pContext,
11118 fts5_tokenizer *pTokenizer,
11119 void (*xDestroy)(void*)
11120 );
11121
11122 /* Find an existing tokenizer */
11123 int (*xFindTokenizer)(
11124 fts5_api *pApi,
11125 const char *zName,
11126 void **ppContext,
11127 fts5_tokenizer *pTokenizer
11128 );
11129
11130 /* Create a new auxiliary function */
11131 int (*xCreateFunction)(
11132 fts5_api *pApi,
11133 const char *zName,
11134 void *pContext,
11135 fts5_extension_function xFunction,
11136 void (*xDestroy)(void*)
11137 );
11138};
11139
11140/*
11141** END OF REGISTRATION API
11142*************************************************************************/
11143
11144
11145// This is a DuckDB hack
11146#ifdef _WIN32
11147typedef const wchar_t* LPCWSTR;
11148typedef wchar_t* LPWSTR, *PWSTR;
11149
11150/* string conversion routines only needed on Win32 */
11151SQLITE_API char *sqlite3_win32_unicode_to_utf8(LPCWSTR);
11152SQLITE_API char *sqlite3_win32_mbcs_to_utf8_v2(const char *, int);
11153SQLITE_API char *sqlite3_win32_utf8_to_mbcs_v2(const char *, int);
11154SQLITE_API LPWSTR sqlite3_win32_utf8_to_unicode(const char *zText);
11155#endif
11156
11157
11158#ifdef __cplusplus
11159} /* end of the 'extern "C"' block */
11160#endif
11161
11162#endif /* _FTS5_H */
11163
11164/******** End of fts5.h *********/
11165