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Fix null pointer dereference in the glines module.
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1/*
2** 2001 September 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 to make minor changes if
22** 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 suppose 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** @(#) $Id: sqlite.h.in,v 1.394 2008/08/25 21:23:02 drh Exp $
34*/
35#ifndef _SQLITE3_H_
36#define _SQLITE3_H_
37#include <stdarg.h> /* Needed for the definition of va_list */
38
39/*
40** Make sure we can call this stuff from C++.
41*/
42#ifdef __cplusplus
43extern "C" {
44#endif
45
46
47/*
48** Add the ability to override 'extern'
49*/
50#ifndef SQLITE_EXTERN
51# define SQLITE_EXTERN extern
52#endif
53
54/*
55** Add the ability to mark interfaces as deprecated.
56*/
57#if (__GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1))
58 /* GCC added the deprecated attribute in version 3.1 */
59 #define SQLITE_DEPRECATED __attribute__ ((deprecated))
60#elif defined(_MSC_VER)
61 #define SQLITE_DEPRECATED __declspec(deprecated)
62#else
63 #define SQLITE_DEPRECATED
64#endif
65
66/*
67** Add the ability to mark interfaces as experimental.
68*/
69#if (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3))
70 /* I can confirm that it does not work on version 4.1.0... */
71 /* First appears in GCC docs for version 4.3.0 */
72 #define SQLITE_EXPERIMENTAL __attribute__ ((warning ("is experimental")))
73#elif defined(_MSC_VER)
74 #define SQLITE_EXPERIMENTAL __declspec(deprecated("was declared experimental"))
75#else
76 #define SQLITE_EXPERIMENTAL
77#endif
78
79/*
80** Ensure these symbols were not defined by some previous header file.
81*/
82#ifdef SQLITE_VERSION
83# undef SQLITE_VERSION
84#endif
85#ifdef SQLITE_VERSION_NUMBER
86# undef SQLITE_VERSION_NUMBER
87#endif
88
89/*
90** CAPI3REF: Compile-Time Library Version Numbers {H10010} <S60100>
91**
92** The SQLITE_VERSION and SQLITE_VERSION_NUMBER #defines in
93** the sqlite3.h file specify the version of SQLite with which
94** that header file is associated.
95**
96** The "version" of SQLite is a string of the form "X.Y.Z".
97** The phrase "alpha" or "beta" might be appended after the Z.
98** The X value is major version number always 3 in SQLite3.
99** The X value only changes when backwards compatibility is
100** broken and we intend to never break backwards compatibility.
101** The Y value is the minor version number and only changes when
102** there are major feature enhancements that are forwards compatible
103** but not backwards compatible.
104** The Z value is the release number and is incremented with
105** each release but resets back to 0 whenever Y is incremented.
106**
107** See also: [sqlite3_libversion()] and [sqlite3_libversion_number()].
108**
109** INVARIANTS:
110**
111** {H10011} The SQLITE_VERSION #define in the sqlite3.h header file shall
112** evaluate to a string literal that is the SQLite version
113** with which the header file is associated.
114**
115** {H10014} The SQLITE_VERSION_NUMBER #define shall resolve to an integer
116** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z
117** are the major version, minor version, and release number.
118*/
119#define SQLITE_VERSION "3.6.2"
120#define SQLITE_VERSION_NUMBER 3006002
121
122/*
123** CAPI3REF: Run-Time Library Version Numbers {H10020} <S60100>
124** KEYWORDS: sqlite3_version
125**
126** These features provide the same information as the [SQLITE_VERSION]
127** and [SQLITE_VERSION_NUMBER] #defines in the header, but are associated
128** with the library instead of the header file. Cautious programmers might
129** include a check in their application to verify that
130** sqlite3_libversion_number() always returns the value
131** [SQLITE_VERSION_NUMBER].
132**
133** The sqlite3_libversion() function returns the same information as is
134** in the sqlite3_version[] string constant. The function is provided
135** for use in DLLs since DLL users usually do not have direct access to string
136** constants within the DLL.
137**
138** INVARIANTS:
139**
140** {H10021} The [sqlite3_libversion_number()] interface shall return
141** an integer equal to [SQLITE_VERSION_NUMBER].
142**
143** {H10022} The [sqlite3_version] string constant shall contain
144** the text of the [SQLITE_VERSION] string.
145**
146** {H10023} The [sqlite3_libversion()] function shall return
147** a pointer to the [sqlite3_version] string constant.
148*/
149SQLITE_EXTERN const char sqlite3_version[];
150const char *sqlite3_libversion(void);
151int sqlite3_libversion_number(void);
152
153/*
154** CAPI3REF: Test To See If The Library Is Threadsafe {H10100} <S60100>
155**
156** SQLite can be compiled with or without mutexes. When
157** the [SQLITE_THREADSAFE] C preprocessor macro is true, mutexes
158** are enabled and SQLite is threadsafe. When that macro is false,
159** the mutexes are omitted. Without the mutexes, it is not safe
160** to use SQLite concurrently from more than one thread.
161**
162** Enabling mutexes incurs a measurable performance penalty.
163** So if speed is of utmost importance, it makes sense to disable
164** the mutexes. But for maximum safety, mutexes should be enabled.
165** The default behavior is for mutexes to be enabled.
166**
167** This interface can be used by a program to make sure that the
168** version of SQLite that it is linking against was compiled with
169** the desired setting of the [SQLITE_THREADSAFE] macro.
170**
171** This interface only reports on the compile-time mutex setting
172** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with
173** SQLITE_THREADSAFE=1 then mutexes are enabled by default but
174** can be fully or partially disabled using a call to [sqlite3_config()]
175** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
176** or [SQLITE_CONFIG_MUTEX]. The return value of this function shows
177** only the default compile-time setting, not any run-time changes
178** to that setting.
179**
180** INVARIANTS:
181**
182** {H10101} The [sqlite3_threadsafe()] function shall return nonzero if
183** SQLite was compiled with the its mutexes enabled by default
184** or zero if SQLite was compiled such that mutexes are
185** permanently disabled.
186**
187** {H10102} The value returned by the [sqlite3_threadsafe()] function
188** shall not change when mutex setting are modified at
189** runtime using the [sqlite3_config()] interface and
190** especially the [SQLITE_CONFIG_SINGLETHREAD],
191** [SQLITE_CONFIG_MULTITHREAD], [SQLITE_CONFIG_SERIALIZED],
192** and [SQLITE_CONFIG_MUTEX] verbs.
193*/
194int sqlite3_threadsafe(void);
195
196/*
197** CAPI3REF: Database Connection Handle {H12000} <S40200>
198** KEYWORDS: {database connection} {database connections}
199**
200** Each open SQLite database is represented by a pointer to an instance of
201** the opaque structure named "sqlite3". It is useful to think of an sqlite3
202** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and
203** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
204** is its destructor. There are many other interfaces (such as
205** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
206** [sqlite3_busy_timeout()] to name but three) that are methods on an
207** sqlite3 object.
208*/
209typedef struct sqlite3 sqlite3;
210
211/*
212** CAPI3REF: 64-Bit Integer Types {H10200} <S10110>
213** KEYWORDS: sqlite_int64 sqlite_uint64
214**
215** Because there is no cross-platform way to specify 64-bit integer types
216** SQLite includes typedefs for 64-bit signed and unsigned integers.
217**
218** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
219** The sqlite_int64 and sqlite_uint64 types are supported for backwards
220** compatibility only.
221**
222** INVARIANTS:
223**
224** {H10201} The [sqlite_int64] and [sqlite3_int64] type shall specify
225** a 64-bit signed integer.
226**
227** {H10202} The [sqlite_uint64] and [sqlite3_uint64] type shall specify
228** a 64-bit unsigned integer.
229*/
230#ifdef SQLITE_INT64_TYPE
231 typedef SQLITE_INT64_TYPE sqlite_int64;
232 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
233#elif defined(_MSC_VER) || defined(__BORLANDC__)
234 typedef __int64 sqlite_int64;
235 typedef unsigned __int64 sqlite_uint64;
236#else
237 typedef long long int sqlite_int64;
238 typedef unsigned long long int sqlite_uint64;
239#endif
240typedef sqlite_int64 sqlite3_int64;
241typedef sqlite_uint64 sqlite3_uint64;
242
243/*
244** If compiling for a processor that lacks floating point support,
245** substitute integer for floating-point.
246*/
247#ifdef SQLITE_OMIT_FLOATING_POINT
248# define double sqlite3_int64
249#endif
250
251/*
252** CAPI3REF: Closing A Database Connection {H12010} <S30100><S40200>
253**
254** This routine is the destructor for the [sqlite3] object.
255**
256** Applications should [sqlite3_finalize | finalize] all [prepared statements]
257** and [sqlite3_blob_close | close] all [BLOB handles] associated with
258** the [sqlite3] object prior to attempting to close the object.
259** The [sqlite3_next_stmt()] interface can be used to locate all
260** [prepared statements] associated with a [database connection] if desired.
261** Typical code might look like this:
262**
263** <blockquote><pre>
264** sqlite3_stmt *pStmt;
265** while( (pStmt = sqlite3_next_stmt(db, 0))!=0 ){
266** &nbsp; sqlite3_finalize(pStmt);
267** }
268** </pre></blockquote>
269**
270** If [sqlite3_close()] is invoked while a transaction is open,
271** the transaction is automatically rolled back.
272**
273** INVARIANTS:
274**
275** {H12011} A successful call to [sqlite3_close(C)] shall destroy the
276** [database connection] object C.
277**
278** {H12012} A successful call to [sqlite3_close(C)] shall return SQLITE_OK.
279**
280** {H12013} A successful call to [sqlite3_close(C)] shall release all
281** memory and system resources associated with [database connection]
282** C.
283**
284** {H12014} A call to [sqlite3_close(C)] on a [database connection] C that
285** has one or more open [prepared statements] shall fail with
286** an [SQLITE_BUSY] error code.
287**
288** {H12015} A call to [sqlite3_close(C)] where C is a NULL pointer shall
289** return SQLITE_OK.
290**
291** {H12019} When [sqlite3_close(C)] is invoked on a [database connection] C
292** that has a pending transaction, the transaction shall be
293** rolled back.
294**
295** ASSUMPTIONS:
296**
297** {A12016} The C parameter to [sqlite3_close(C)] must be either a NULL
298** pointer or an [sqlite3] object pointer obtained
299** from [sqlite3_open()], [sqlite3_open16()], or
300** [sqlite3_open_v2()], and not previously closed.
301*/
302int sqlite3_close(sqlite3 *);
303
304/*
305** The type for a callback function.
306** This is legacy and deprecated. It is included for historical
307** compatibility and is not documented.
308*/
309typedef int (*sqlite3_callback)(void*,int,char**, char**);
310
311/*
312** CAPI3REF: One-Step Query Execution Interface {H12100} <S10000>
313**
314** The sqlite3_exec() interface is a convenient way of running one or more
315** SQL statements without having to write a lot of C code. The UTF-8 encoded
316** SQL statements are passed in as the second parameter to sqlite3_exec().
317** The statements are evaluated one by one until either an error or
318** an interrupt is encountered, or until they are all done. The 3rd parameter
319** is an optional callback that is invoked once for each row of any query
320** results produced by the SQL statements. The 5th parameter tells where
321** to write any error messages.
322**
323** The error message passed back through the 5th parameter is held
324** in memory obtained from [sqlite3_malloc()]. To avoid a memory leak,
325** the calling application should call [sqlite3_free()] on any error
326** message returned through the 5th parameter when it has finished using
327** the error message.
328**
329** If the SQL statement in the 2nd parameter is NULL or an empty string
330** or a string containing only whitespace and comments, then no SQL
331** statements are evaluated and the database is not changed.
332**
333** The sqlite3_exec() interface is implemented in terms of
334** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()].
335** The sqlite3_exec() routine does nothing to the database that cannot be done
336** by [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()].
337**
338** INVARIANTS:
339**
340** {H12101} A successful invocation of [sqlite3_exec(D,S,C,A,E)]
341** shall sequentially evaluate all of the UTF-8 encoded,
342** semicolon-separated SQL statements in the zero-terminated
343** string S within the context of the [database connection] D.
344**
345** {H12102} If the S parameter to [sqlite3_exec(D,S,C,A,E)] is NULL then
346** the actions of the interface shall be the same as if the
347** S parameter were an empty string.
348**
349** {H12104} The return value of [sqlite3_exec()] shall be [SQLITE_OK] if all
350** SQL statements run successfully and to completion.
351**
352** {H12105} The return value of [sqlite3_exec()] shall be an appropriate
353** non-zero [error code] if any SQL statement fails.
354**
355** {H12107} If one or more of the SQL statements handed to [sqlite3_exec()]
356** return results and the 3rd parameter is not NULL, then
357** the callback function specified by the 3rd parameter shall be
358** invoked once for each row of result.
359**
360** {H12110} If the callback returns a non-zero value then [sqlite3_exec()]
361** shall abort the SQL statement it is currently evaluating,
362** skip all subsequent SQL statements, and return [SQLITE_ABORT].
363**
364** {H12113} The [sqlite3_exec()] routine shall pass its 4th parameter through
365** as the 1st parameter of the callback.
366**
367** {H12116} The [sqlite3_exec()] routine shall set the 2nd parameter of its
368** callback to be the number of columns in the current row of
369** result.
370**
371** {H12119} The [sqlite3_exec()] routine shall set the 3rd parameter of its
372** callback to be an array of pointers to strings holding the
373** values for each column in the current result set row as
374** obtained from [sqlite3_column_text()].
375**
376** {H12122} The [sqlite3_exec()] routine shall set the 4th parameter of its
377** callback to be an array of pointers to strings holding the
378** names of result columns as obtained from [sqlite3_column_name()].
379**
380** {H12125} If the 3rd parameter to [sqlite3_exec()] is NULL then
381** [sqlite3_exec()] shall silently discard query results.
382**
383** {H12131} If an error occurs while parsing or evaluating any of the SQL
384** statements in the S parameter of [sqlite3_exec(D,S,C,A,E)] and if
385** the E parameter is not NULL, then [sqlite3_exec()] shall store
386** in *E an appropriate error message written into memory obtained
387** from [sqlite3_malloc()].
388**
389** {H12134} The [sqlite3_exec(D,S,C,A,E)] routine shall set the value of
390** *E to NULL if E is not NULL and there are no errors.
391**
392** {H12137} The [sqlite3_exec(D,S,C,A,E)] function shall set the [error code]
393** and message accessible via [sqlite3_errcode()],
394** [sqlite3_errmsg()], and [sqlite3_errmsg16()].
395**
396** {H12138} If the S parameter to [sqlite3_exec(D,S,C,A,E)] is NULL or an
397** empty string or contains nothing other than whitespace, comments,
398** and/or semicolons, then results of [sqlite3_errcode()],
399** [sqlite3_errmsg()], and [sqlite3_errmsg16()]
400** shall reset to indicate no errors.
401**
402** ASSUMPTIONS:
403**
404** {A12141} The first parameter to [sqlite3_exec()] must be an valid and open
405** [database connection].
406**
407** {A12142} The database connection must not be closed while
408** [sqlite3_exec()] is running.
409**
410** {A12143} The calling function should use [sqlite3_free()] to free
411** the memory that *errmsg is left pointing at once the error
412** message is no longer needed.
413**
414** {A12145} The SQL statement text in the 2nd parameter to [sqlite3_exec()]
415** must remain unchanged while [sqlite3_exec()] is running.
416*/
417int sqlite3_exec(
418 sqlite3*, /* An open database */
419 const char *sql, /* SQL to be evaluated */
420 int (*callback)(void*,int,char**,char**), /* Callback function */
421 void *, /* 1st argument to callback */
422 char **errmsg /* Error msg written here */
423);
424
425/*
426** CAPI3REF: Result Codes {H10210} <S10700>
427** KEYWORDS: SQLITE_OK {error code} {error codes}
428** KEYWORDS: {result code} {result codes}
429**
430** Many SQLite functions return an integer result code from the set shown
431** here in order to indicates success or failure.
432**
433** New error codes may be added in future versions of SQLite.
434**
435** See also: [SQLITE_IOERR_READ | extended result codes]
436*/
437#define SQLITE_OK 0 /* Successful result */
438/* beginning-of-error-codes */
439#define SQLITE_ERROR 1 /* SQL error or missing database */
440#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */
441#define SQLITE_PERM 3 /* Access permission denied */
442#define SQLITE_ABORT 4 /* Callback routine requested an abort */
443#define SQLITE_BUSY 5 /* The database file is locked */
444#define SQLITE_LOCKED 6 /* A table in the database is locked */
445#define SQLITE_NOMEM 7 /* A malloc() failed */
446#define SQLITE_READONLY 8 /* Attempt to write a readonly database */
447#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/
448#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */
449#define SQLITE_CORRUPT 11 /* The database disk image is malformed */
450#define SQLITE_NOTFOUND 12 /* NOT USED. Table or record not found */
451#define SQLITE_FULL 13 /* Insertion failed because database is full */
452#define SQLITE_CANTOPEN 14 /* Unable to open the database file */
453#define SQLITE_PROTOCOL 15 /* NOT USED. Database lock protocol error */
454#define SQLITE_EMPTY 16 /* Database is empty */
455#define SQLITE_SCHEMA 17 /* The database schema changed */
456#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */
457#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */
458#define SQLITE_MISMATCH 20 /* Data type mismatch */
459#define SQLITE_MISUSE 21 /* Library used incorrectly */
460#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */
461#define SQLITE_AUTH 23 /* Authorization denied */
462#define SQLITE_FORMAT 24 /* Auxiliary database format error */
463#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */
464#define SQLITE_NOTADB 26 /* File opened that is not a database file */
465#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */
466#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */
467/* end-of-error-codes */
468
469/*
470** CAPI3REF: Extended Result Codes {H10220} <S10700>
471** KEYWORDS: {extended error code} {extended error codes}
472** KEYWORDS: {extended result code} {extended result codes}
473**
474** In its default configuration, SQLite API routines return one of 26 integer
475** [SQLITE_OK | result codes]. However, experience has shown that many of
476** these result codes are too coarse-grained. They do not provide as
477** much information about problems as programmers might like. In an effort to
478** address this, newer versions of SQLite (version 3.3.8 and later) include
479** support for additional result codes that provide more detailed information
480** about errors. The extended result codes are enabled or disabled
481** on a per database connection basis using the
482** [sqlite3_extended_result_codes()] API.
483**
484** Some of the available extended result codes are listed here.
485** One may expect the number of extended result codes will be expand
486** over time. Software that uses extended result codes should expect
487** to see new result codes in future releases of SQLite.
488**
489** The SQLITE_OK result code will never be extended. It will always
490** be exactly zero.
491**
492** INVARIANTS:
493**
494** {H10223} The symbolic name for an extended result code shall contains
495** a related primary result code as a prefix.
496**
497** {H10224} Primary result code names shall contain a single "_" character.
498**
499** {H10225} Extended result code names shall contain two or more "_" characters.
500**
501** {H10226} The numeric value of an extended result code shall contain the
502** numeric value of its corresponding primary result code in
503** its least significant 8 bits.
504*/
505#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8))
506#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8))
507#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8))
508#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8))
509#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8))
510#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8))
511#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8))
512#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8))
513#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8))
514#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8))
515#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8))
516#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8))
517#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8))
518#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))
519#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8))
520
521/*
522** CAPI3REF: Flags For File Open Operations {H10230} <H11120> <H12700>
523**
524** These bit values are intended for use in the
525** 3rd parameter to the [sqlite3_open_v2()] interface and
526** in the 4th parameter to the xOpen method of the
527** [sqlite3_vfs] object.
528*/
529#define SQLITE_OPEN_READONLY 0x00000001
530#define SQLITE_OPEN_READWRITE 0x00000002
531#define SQLITE_OPEN_CREATE 0x00000004
532#define SQLITE_OPEN_DELETEONCLOSE 0x00000008
533#define SQLITE_OPEN_EXCLUSIVE 0x00000010
534#define SQLITE_OPEN_MAIN_DB 0x00000100
535#define SQLITE_OPEN_TEMP_DB 0x00000200
536#define SQLITE_OPEN_TRANSIENT_DB 0x00000400
537#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800
538#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000
539#define SQLITE_OPEN_SUBJOURNAL 0x00002000
540#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000
541#define SQLITE_OPEN_NOMUTEX 0x00008000
542#define SQLITE_OPEN_FULLMUTEX 0x00010000
543
544/*
545** CAPI3REF: Device Characteristics {H10240} <H11120>
546**
547** The xDeviceCapabilities method of the [sqlite3_io_methods]
548** object returns an integer which is a vector of the these
549** bit values expressing I/O characteristics of the mass storage
550** device that holds the file that the [sqlite3_io_methods]
551** refers to.
552**
553** The SQLITE_IOCAP_ATOMIC property means that all writes of
554** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
555** mean that writes of blocks that are nnn bytes in size and
556** are aligned to an address which is an integer multiple of
557** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
558** that when data is appended to a file, the data is appended
559** first then the size of the file is extended, never the other
560** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
561** information is written to disk in the same order as calls
562** to xWrite().
563*/
564#define SQLITE_IOCAP_ATOMIC 0x00000001
565#define SQLITE_IOCAP_ATOMIC512 0x00000002
566#define SQLITE_IOCAP_ATOMIC1K 0x00000004
567#define SQLITE_IOCAP_ATOMIC2K 0x00000008
568#define SQLITE_IOCAP_ATOMIC4K 0x00000010
569#define SQLITE_IOCAP_ATOMIC8K 0x00000020
570#define SQLITE_IOCAP_ATOMIC16K 0x00000040
571#define SQLITE_IOCAP_ATOMIC32K 0x00000080
572#define SQLITE_IOCAP_ATOMIC64K 0x00000100
573#define SQLITE_IOCAP_SAFE_APPEND 0x00000200
574#define SQLITE_IOCAP_SEQUENTIAL 0x00000400
575
576/*
577** CAPI3REF: File Locking Levels {H10250} <H11120> <H11310>
578**
579** SQLite uses one of these integer values as the second
580** argument to calls it makes to the xLock() and xUnlock() methods
581** of an [sqlite3_io_methods] object.
582*/
583#define SQLITE_LOCK_NONE 0
584#define SQLITE_LOCK_SHARED 1
585#define SQLITE_LOCK_RESERVED 2
586#define SQLITE_LOCK_PENDING 3
587#define SQLITE_LOCK_EXCLUSIVE 4
588
589/*
590** CAPI3REF: Synchronization Type Flags {H10260} <H11120>
591**
592** When SQLite invokes the xSync() method of an
593** [sqlite3_io_methods] object it uses a combination of
594** these integer values as the second argument.
595**
596** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
597** sync operation only needs to flush data to mass storage. Inode
598** information need not be flushed. The SQLITE_SYNC_NORMAL flag means
599** to use normal fsync() semantics. The SQLITE_SYNC_FULL flag means
600** to use Mac OS-X style fullsync instead of fsync().
601*/
602#define SQLITE_SYNC_NORMAL 0x00002
603#define SQLITE_SYNC_FULL 0x00003
604#define SQLITE_SYNC_DATAONLY 0x00010
605
606/*
607** CAPI3REF: OS Interface Open File Handle {H11110} <S20110>
608**
609** An [sqlite3_file] object represents an open file in the OS
610** interface layer. Individual OS interface implementations will
611** want to subclass this object by appending additional fields
612** for their own use. The pMethods entry is a pointer to an
613** [sqlite3_io_methods] object that defines methods for performing
614** I/O operations on the open file.
615*/
616typedef struct sqlite3_file sqlite3_file;
617struct sqlite3_file {
618 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */
619};
620
621/*
622** CAPI3REF: OS Interface File Virtual Methods Object {H11120} <S20110>
623**
624** Every file opened by the [sqlite3_vfs] xOpen method populates an
625** [sqlite3_file] object (or, more commonly, a subclass of the
626** [sqlite3_file] object) with a pointer to an instance of this object.
627** This object defines the methods used to perform various operations
628** against the open file represented by the [sqlite3_file] object.
629**
630** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
631** [SQLITE_SYNC_FULL]. The first choice is the normal fsync().
632** The second choice is a Mac OS-X style fullsync. The [SQLITE_SYNC_DATAONLY]
633** flag may be ORed in to indicate that only the data of the file
634** and not its inode needs to be synced.
635**
636** The integer values to xLock() and xUnlock() are one of
637** <ul>
638** <li> [SQLITE_LOCK_NONE],
639** <li> [SQLITE_LOCK_SHARED],
640** <li> [SQLITE_LOCK_RESERVED],
641** <li> [SQLITE_LOCK_PENDING], or
642** <li> [SQLITE_LOCK_EXCLUSIVE].
643** </ul>
644** xLock() increases the lock. xUnlock() decreases the lock.
645** The xCheckReservedLock() method checks whether any database connection,
646** either in this process or in some other process, is holding a RESERVED,
647** PENDING, or EXCLUSIVE lock on the file. It returns true
648** if such a lock exists and false otherwise.
649**
650** The xFileControl() method is a generic interface that allows custom
651** VFS implementations to directly control an open file using the
652** [sqlite3_file_control()] interface. The second "op" argument is an
653** integer opcode. The third argument is a generic pointer intended to
654** point to a structure that may contain arguments or space in which to
655** write return values. Potential uses for xFileControl() might be
656** functions to enable blocking locks with timeouts, to change the
657** locking strategy (for example to use dot-file locks), to inquire
658** about the status of a lock, or to break stale locks. The SQLite
659** core reserves all opcodes less than 100 for its own use.
660** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available.
661** Applications that define a custom xFileControl method should use opcodes
662** greater than 100 to avoid conflicts.
663**
664** The xSectorSize() method returns the sector size of the
665** device that underlies the file. The sector size is the
666** minimum write that can be performed without disturbing
667** other bytes in the file. The xDeviceCharacteristics()
668** method returns a bit vector describing behaviors of the
669** underlying device:
670**
671** <ul>
672** <li> [SQLITE_IOCAP_ATOMIC]
673** <li> [SQLITE_IOCAP_ATOMIC512]
674** <li> [SQLITE_IOCAP_ATOMIC1K]
675** <li> [SQLITE_IOCAP_ATOMIC2K]
676** <li> [SQLITE_IOCAP_ATOMIC4K]
677** <li> [SQLITE_IOCAP_ATOMIC8K]
678** <li> [SQLITE_IOCAP_ATOMIC16K]
679** <li> [SQLITE_IOCAP_ATOMIC32K]
680** <li> [SQLITE_IOCAP_ATOMIC64K]
681** <li> [SQLITE_IOCAP_SAFE_APPEND]
682** <li> [SQLITE_IOCAP_SEQUENTIAL]
683** </ul>
684**
685** The SQLITE_IOCAP_ATOMIC property means that all writes of
686** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
687** mean that writes of blocks that are nnn bytes in size and
688** are aligned to an address which is an integer multiple of
689** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
690** that when data is appended to a file, the data is appended
691** first then the size of the file is extended, never the other
692** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
693** information is written to disk in the same order as calls
694** to xWrite().
695*/
696typedef struct sqlite3_io_methods sqlite3_io_methods;
697struct sqlite3_io_methods {
698 int iVersion;
699 int (*xClose)(sqlite3_file*);
700 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
701 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
702 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
703 int (*xSync)(sqlite3_file*, int flags);
704 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
705 int (*xLock)(sqlite3_file*, int);
706 int (*xUnlock)(sqlite3_file*, int);
707 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);
708 int (*xFileControl)(sqlite3_file*, int op, void *pArg);
709 int (*xSectorSize)(sqlite3_file*);
710 int (*xDeviceCharacteristics)(sqlite3_file*);
711 /* Additional methods may be added in future releases */
712};
713
714/*
715** CAPI3REF: Standard File Control Opcodes {H11310} <S30800>
716**
717** These integer constants are opcodes for the xFileControl method
718** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
719** interface.
720**
721** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This
722** opcode causes the xFileControl method to write the current state of
723** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
724** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
725** into an integer that the pArg argument points to. This capability
726** is used during testing and only needs to be supported when SQLITE_TEST
727** is defined.
728*/
729#define SQLITE_FCNTL_LOCKSTATE 1
730
731/*
732** CAPI3REF: Mutex Handle {H17110} <S20130>
733**
734** The mutex module within SQLite defines [sqlite3_mutex] to be an
735** abstract type for a mutex object. The SQLite core never looks
736** at the internal representation of an [sqlite3_mutex]. It only
737** deals with pointers to the [sqlite3_mutex] object.
738**
739** Mutexes are created using [sqlite3_mutex_alloc()].
740*/
741typedef struct sqlite3_mutex sqlite3_mutex;
742
743/*
744** CAPI3REF: OS Interface Object {H11140} <S20100>
745**
746** An instance of the sqlite3_vfs object defines the interface between
747** the SQLite core and the underlying operating system. The "vfs"
748** in the name of the object stands for "virtual file system".
749**
750** The value of the iVersion field is initially 1 but may be larger in
751** future versions of SQLite. Additional fields may be appended to this
752** object when the iVersion value is increased. Note that the structure
753** of the sqlite3_vfs object changes in the transaction between
754** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not
755** modified.
756**
757** The szOsFile field is the size of the subclassed [sqlite3_file]
758** structure used by this VFS. mxPathname is the maximum length of
759** a pathname in this VFS.
760**
761** Registered sqlite3_vfs objects are kept on a linked list formed by
762** the pNext pointer. The [sqlite3_vfs_register()]
763** and [sqlite3_vfs_unregister()] interfaces manage this list
764** in a thread-safe way. The [sqlite3_vfs_find()] interface
765** searches the list. Neither the application code nor the VFS
766** implementation should use the pNext pointer.
767**
768** The pNext field is the only field in the sqlite3_vfs
769** structure that SQLite will ever modify. SQLite will only access
770** or modify this field while holding a particular static mutex.
771** The application should never modify anything within the sqlite3_vfs
772** object once the object has been registered.
773**
774** The zName field holds the name of the VFS module. The name must
775** be unique across all VFS modules.
776**
777** {H11141} SQLite will guarantee that the zFilename parameter to xOpen
778** is either a NULL pointer or string obtained
779** from xFullPathname(). SQLite further guarantees that
780** the string will be valid and unchanged until xClose() is
781** called. {END} Because of the previous sentense,
782** the [sqlite3_file] can safely store a pointer to the
783** filename if it needs to remember the filename for some reason.
784** If the zFilename parameter is xOpen is a NULL pointer then xOpen
785** must invite its own temporary name for the file. Whenever the
786** xFilename parameter is NULL it will also be the case that the
787** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
788**
789** {H11142} The flags argument to xOpen() includes all bits set in
790** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()]
791** or [sqlite3_open16()] is used, then flags includes at least
792** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. {END}
793** If xOpen() opens a file read-only then it sets *pOutFlags to
794** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set.
795**
796** {H11143} SQLite will also add one of the following flags to the xOpen()
797** call, depending on the object being opened:
798**
799** <ul>
800** <li> [SQLITE_OPEN_MAIN_DB]
801** <li> [SQLITE_OPEN_MAIN_JOURNAL]
802** <li> [SQLITE_OPEN_TEMP_DB]
803** <li> [SQLITE_OPEN_TEMP_JOURNAL]
804** <li> [SQLITE_OPEN_TRANSIENT_DB]
805** <li> [SQLITE_OPEN_SUBJOURNAL]
806** <li> [SQLITE_OPEN_MASTER_JOURNAL]
807** </ul> {END}
808**
809** The file I/O implementation can use the object type flags to
810** change the way it deals with files. For example, an application
811** that does not care about crash recovery or rollback might make
812** the open of a journal file a no-op. Writes to this journal would
813** also be no-ops, and any attempt to read the journal would return
814** SQLITE_IOERR. Or the implementation might recognize that a database
815** file will be doing page-aligned sector reads and writes in a random
816** order and set up its I/O subsystem accordingly.
817**
818** SQLite might also add one of the following flags to the xOpen method:
819**
820** <ul>
821** <li> [SQLITE_OPEN_DELETEONCLOSE]
822** <li> [SQLITE_OPEN_EXCLUSIVE]
823** </ul>
824**
825** {H11145} The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
826** deleted when it is closed. {H11146} The [SQLITE_OPEN_DELETEONCLOSE]
827** will be set for TEMP databases, journals and for subjournals.
828**
829** {H11147} The [SQLITE_OPEN_EXCLUSIVE] flag means the file should be opened
830** for exclusive access. This flag is set for all files except
831** for the main database file.
832**
833** {H11148} At least szOsFile bytes of memory are allocated by SQLite
834** to hold the [sqlite3_file] structure passed as the third
835** argument to xOpen. {END} The xOpen method does not have to
836** allocate the structure; it should just fill it in.
837**
838** {H11149} The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
839** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
840** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
841** to test whether a file is at least readable. {END} The file can be a
842** directory.
843**
844** {H11150} SQLite will always allocate at least mxPathname+1 bytes for the
845** output buffer xFullPathname. {H11151} The exact size of the output buffer
846** is also passed as a parameter to both methods. {END} If the output buffer
847** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
848** handled as a fatal error by SQLite, vfs implementations should endeavor
849** to prevent this by setting mxPathname to a sufficiently large value.
850**
851** The xRandomness(), xSleep(), and xCurrentTime() interfaces
852** are not strictly a part of the filesystem, but they are
853** included in the VFS structure for completeness.
854** The xRandomness() function attempts to return nBytes bytes
855** of good-quality randomness into zOut. The return value is
856** the actual number of bytes of randomness obtained.
857** The xSleep() method causes the calling thread to sleep for at
858** least the number of microseconds given. The xCurrentTime()
859** method returns a Julian Day Number for the current date and time.
860*/
861typedef struct sqlite3_vfs sqlite3_vfs;
862struct sqlite3_vfs {
863 int iVersion; /* Structure version number */
864 int szOsFile; /* Size of subclassed sqlite3_file */
865 int mxPathname; /* Maximum file pathname length */
866 sqlite3_vfs *pNext; /* Next registered VFS */
867 const char *zName; /* Name of this virtual file system */
868 void *pAppData; /* Pointer to application-specific data */
869 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*,
870 int flags, int *pOutFlags);
871 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
872 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);
873 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
874 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
875 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
876 void *(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol);
877 void (*xDlClose)(sqlite3_vfs*, void*);
878 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
879 int (*xSleep)(sqlite3_vfs*, int microseconds);
880 int (*xCurrentTime)(sqlite3_vfs*, double*);
881 int (*xGetLastError)(sqlite3_vfs*, int, char *);
882 /* New fields may be appended in figure versions. The iVersion
883 ** value will increment whenever this happens. */
884};
885
886/*
887** CAPI3REF: Flags for the xAccess VFS method {H11190} <H11140>
888**
889** {H11191} These integer constants can be used as the third parameter to
890** the xAccess method of an [sqlite3_vfs] object. {END} They determine
891** what kind of permissions the xAccess method is looking for.
892** {H11192} With SQLITE_ACCESS_EXISTS, the xAccess method
893** simply checks whether the file exists.
894** {H11193} With SQLITE_ACCESS_READWRITE, the xAccess method
895** checks whether the file is both readable and writable.
896** {H11194} With SQLITE_ACCESS_READ, the xAccess method
897** checks whether the file is readable.
898*/
899#define SQLITE_ACCESS_EXISTS 0
900#define SQLITE_ACCESS_READWRITE 1
901#define SQLITE_ACCESS_READ 2
902
903/*
904** CAPI3REF: Initialize The SQLite Library {H10130} <S20000><S30100>
905**
906** The sqlite3_initialize() routine initializes the
907** SQLite library. The sqlite3_shutdown() routine
908** deallocates any resources that were allocated by sqlite3_initialize().
909**
910** A call to sqlite3_initialize() is an "effective" call if it is
911** the first time sqlite3_initialize() is invoked during the lifetime of
912** the process, or if it is the first time sqlite3_initialize() is invoked
913** following a call to sqlite3_shutdown(). Only an effective call
914** of sqlite3_initialize() does any initialization. All other calls
915** are harmless no-ops.
916**
917** Among other things, sqlite3_initialize() shall invoke
918** sqlite3_os_init(). Similarly, sqlite3_shutdown()
919** shall invoke sqlite3_os_end().
920**
921** The sqlite3_initialize() routine returns SQLITE_OK on success.
922** If for some reason, sqlite3_initialize() is unable to initialize
923** the library (perhaps it is unable to allocate a needed resource such
924** as a mutex) it returns an [error code] other than SQLITE_OK.
925**
926** The sqlite3_initialize() routine is called internally by many other
927** SQLite interfaces so that an application usually does not need to
928** invoke sqlite3_initialize() directly. For example, [sqlite3_open()]
929** calls sqlite3_initialize() so the SQLite library will be automatically
930** initialized when [sqlite3_open()] is called if it has not be initialized
931** already. However, if SQLite is compiled with the SQLITE_OMIT_AUTOINIT
932** compile-time option, then the automatic calls to sqlite3_initialize()
933** are omitted and the application must call sqlite3_initialize() directly
934** prior to using any other SQLite interface. For maximum portability,
935** it is recommended that applications always invoke sqlite3_initialize()
936** directly prior to using any other SQLite interface. Future releases
937** of SQLite may require this. In other words, the behavior exhibited
938** when SQLite is compiled with SQLITE_OMIT_AUTOINIT might become the
939** default behavior in some future release of SQLite.
940**
941** The sqlite3_os_init() routine does operating-system specific
942** initialization of the SQLite library. The sqlite3_os_end()
943** routine undoes the effect of sqlite3_os_init(). Typical tasks
944** performed by these routines include allocation or deallocation
945** of static resources, initialization of global variables,
946** setting up a default [sqlite3_vfs] module, or setting up
947** a default configuration using [sqlite3_config()].
948**
949** The application should never invoke either sqlite3_os_init()
950** or sqlite3_os_end() directly. The application should only invoke
951** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init()
952** interface is called automatically by sqlite3_initialize() and
953** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate
954** implementations for sqlite3_os_init() and sqlite3_os_end()
955** are built into SQLite when it is compiled for unix, windows, or os/2.
956** When built for other platforms (using the SQLITE_OS_OTHER=1 compile-time
957** option) the application must supply a suitable implementation for
958** sqlite3_os_init() and sqlite3_os_end(). An application-supplied
959** implementation of sqlite3_os_init() or sqlite3_os_end()
960** must return SQLITE_OK on success and some other [error code] upon
961** failure.
962*/
963int sqlite3_initialize(void);
964int sqlite3_shutdown(void);
965int sqlite3_os_init(void);
966int sqlite3_os_end(void);
967
968/*
969** CAPI3REF: Configuring The SQLite Library {H10145} <S20000><S30200>
970** EXPERIMENTAL
971**
972** The sqlite3_config() interface is used to make global configuration
973** changes to SQLite in order to tune SQLite to the specific needs of
974** the application. The default configuration is recommended for most
975** applications and so this routine is usually not necessary. It is
976** provided to support rare applications with unusual needs.
977**
978** The sqlite3_config() interface is not threadsafe. The application
979** must insure that no other SQLite interfaces are invoked by other
980** threads while sqlite3_config() is running. Furthermore, sqlite3_config()
981** may only be invoked prior to library initialization using
982** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
983** Note, however, that sqlite3_config() can be called as part of the
984** implementation of an application-defined [sqlite3_os_init()].
985**
986** The first argument to sqlite3_config() is an integer
987** [SQLITE_CONFIG_SINGLETHREAD | configuration option] that determines
988** what property of SQLite is to be configured. Subsequent arguments
989** vary depending on the [SQLITE_CONFIG_SINGLETHREAD | configuration option]
990** in the first argument.
991**
992** When a configuration option is set, sqlite3_config() returns SQLITE_OK.
993** If the option is unknown or SQLite is unable to set the option
994** then this routine returns a non-zero [error code].
995*/
996SQLITE_EXPERIMENTAL int sqlite3_config(int, ...);
997
998/*
999** CAPI3REF: Configure database connections {H10180} <S20000>
1000** EXPERIMENTAL
1001**
1002** The sqlite3_db_config() interface is used to make configuration
1003** changes to a [database connection]. The interface is similar to
1004** [sqlite3_config()] except that the changes apply to a single
1005** [database connection] (specified in the first argument). The
1006** sqlite3_db_config() interface can only be used immediately after
1007** the database connection is created using [sqlite3_open()],
1008** [sqlite3_open16()], or [sqlite3_open_v2()].
1009**
1010** The second argument to sqlite3_db_config(D,V,...) is the
1011** configuration verb - an integer code that indicates what
1012** aspect of the [database connection] is being configured.
1013** The only choice for this value is [SQLITE_DBCONFIG_LOOKASIDE].
1014** New verbs are likely to be added in future releases of SQLite.
1015** Additional arguments depend on the verb.
1016*/
1017SQLITE_EXPERIMENTAL int sqlite3_db_config(sqlite3*, int op, ...);
1018
1019/*
1020** CAPI3REF: Memory Allocation Routines {H10155} <S20120>
1021** EXPERIMENTAL
1022**
1023** An instance of this object defines the interface between SQLite
1024** and low-level memory allocation routines.
1025**
1026** This object is used in only one place in the SQLite interface.
1027** A pointer to an instance of this object is the argument to
1028** [sqlite3_config()] when the configuration option is
1029** [SQLITE_CONFIG_MALLOC]. By creating an instance of this object
1030** and passing it to [sqlite3_config()] during configuration, an
1031** application can specify an alternative memory allocation subsystem
1032** for SQLite to use for all of its dynamic memory needs.
1033**
1034** Note that SQLite comes with a built-in memory allocator that is
1035** perfectly adequate for the overwhelming majority of applications
1036** and that this object is only useful to a tiny minority of applications
1037** with specialized memory allocation requirements. This object is
1038** also used during testing of SQLite in order to specify an alternative
1039** memory allocator that simulates memory out-of-memory conditions in
1040** order to verify that SQLite recovers gracefully from such
1041** conditions.
1042**
1043** The xMalloc, xFree, and xRealloc methods must work like the
1044** malloc(), free(), and realloc() functions from the standard library.
1045**
1046** xSize should return the allocated size of a memory allocation
1047** previously obtained from xMalloc or xRealloc. The allocated size
1048** is always at least as big as the requested size but may be larger.
1049**
1050** The xRoundup method returns what would be the allocated size of
1051** a memory allocation given a particular requested size. Most memory
1052** allocators round up memory allocations at least to the next multiple
1053** of 8. Some allocators round up to a larger multiple or to a power of 2.
1054**
1055** The xInit method initializes the memory allocator. (For example,
1056** it might allocate any require mutexes or initialize internal data
1057** structures. The xShutdown method is invoked (indirectly) by
1058** [sqlite3_shutdown()] and should deallocate any resources acquired
1059** by xInit. The pAppData pointer is used as the only parameter to
1060** xInit and xShutdown.
1061*/
1062typedef struct sqlite3_mem_methods sqlite3_mem_methods;
1063struct sqlite3_mem_methods {
1064 void *(*xMalloc)(int); /* Memory allocation function */
1065 void (*xFree)(void*); /* Free a prior allocation */
1066 void *(*xRealloc)(void*,int); /* Resize an allocation */
1067 int (*xSize)(void*); /* Return the size of an allocation */
1068 int (*xRoundup)(int); /* Round up request size to allocation size */
1069 int (*xInit)(void*); /* Initialize the memory allocator */
1070 void (*xShutdown)(void*); /* Deinitialize the memory allocator */
1071 void *pAppData; /* Argument to xInit() and xShutdown() */
1072};
1073
1074/*
1075** CAPI3REF: Configuration Options {H10160} <S20000>
1076** EXPERIMENTAL
1077**
1078** These constants are the available integer configuration options that
1079** can be passed as the first argument to the [sqlite3_config()] interface.
1080**
1081** New configuration options may be added in future releases of SQLite.
1082** Existing configuration options might be discontinued. Applications
1083** should check the return code from [sqlite3_config()] to make sure that
1084** the call worked. The [sqlite3_config()] interface will return a
1085** non-zero [error code] if a discontinued or unsupported configuration option
1086** is invoked.
1087**
1088** <dl>
1089** <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
1090** <dd>There are no arguments to this option. This option disables
1091** all mutexing and puts SQLite into a mode where it can only be used
1092** by a single thread.</dd>
1093**
1094** <dt>SQLITE_CONFIG_MULTITHREAD</dt>
1095** <dd>There are no arguments to this option. This option disables
1096** mutexing on [database connection] and [prepared statement] objects.
1097** The application is responsible for serializing access to
1098** [database connections] and [prepared statements]. But other mutexes
1099** are enabled so that SQLite will be safe to use in a multi-threaded
1100** environment.</dd>
1101**
1102** <dt>SQLITE_CONFIG_SERIALIZED</dt>
1103** <dd>There are no arguments to this option. This option enables
1104** all mutexes including the recursive
1105** mutexes on [database connection] and [prepared statement] objects.
1106** In this mode (which is the default when SQLite is compiled with
1107** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
1108** to [database connections] and [prepared statements] so that the
1109** application is free to use the same [database connection] or the
1110** same [prepared statement] in different threads at the same time.
1111**
1112** <p>This configuration option merely sets the default mutex
1113** behavior to serialize access to [database connections]. Individual
1114** [database connections] can override this setting
1115** using the [SQLITE_OPEN_NOMUTEX] flag to [sqlite3_open_v2()].</p></dd>
1116**
1117** <dt>SQLITE_CONFIG_MALLOC</dt>
1118** <dd>This option takes a single argument which is a pointer to an
1119** instance of the [sqlite3_mem_methods] structure. The argument specifies
1120** alternative low-level memory allocation routines to be used in place of
1121** the memory allocation routines built into SQLite.</dd>
1122**
1123** <dt>SQLITE_CONFIG_GETMALLOC</dt>
1124** <dd>This option takes a single argument which is a pointer to an
1125** instance of the [sqlite3_mem_methods] structure. The [sqlite3_mem_methods]
1126** structure is filled with the currently defined memory allocation routines.
1127** This option can be used to overload the default memory allocation
1128** routines with a wrapper that simulations memory allocation failure or
1129** tracks memory usage, for example.</dd>
1130**
1131** <dt>SQLITE_CONFIG_MEMSTATUS</dt>
1132** <dd>This option takes single argument of type int, interpreted as a
1133** boolean, which enables or disables the collection of memory allocation
1134** statistics. When disabled, the following SQLite interfaces become
1135** non-operational:
1136** <ul>
1137** <li> [sqlite3_memory_used()]
1138** <li> [sqlite3_memory_highwater()]
1139** <li> [sqlite3_soft_heap_limit()]
1140** <li> [sqlite3_status()]
1141** </ul>
1142** </dd>
1143**
1144** <dt>SQLITE_CONFIG_SCRATCH</dt>
1145** <dd>This option specifies a static memory buffer that SQLite can use for
1146** scratch memory. There are three arguments: A pointer to the memory, the
1147** size of each scratch buffer (sz), and the number of buffers (N). The sz
1148** argument must be a multiple of 16. The sz parameter should be a few bytes
1149** larger than the actual scratch space required due internal overhead.
1150** The first
1151** argument should point to an allocation of at least sz*N bytes of memory.
1152** SQLite will use no more than one scratch buffer at once per thread, so
1153** N should be set to the expected maximum number of threads. The sz
1154** parameter should be 6 times the size of the largest database page size.
1155** Scratch buffers are used as part of the btree balance operation. If
1156** The btree balancer needs additional memory beyond what is provided by
1157** scratch buffers or if no scratch buffer space is specified, then SQLite
1158** goes to [sqlite3_malloc()] to obtain the memory it needs.</dd>
1159**
1160** <dt>SQLITE_CONFIG_PAGECACHE</dt>
1161** <dd>This option specifies a static memory buffer that SQLite can use for
1162** the database page cache. There are three arguments: A pointer to the
1163** memory, the size of each page buffer (sz), and the number of pages (N).
1164** The sz argument must be a power of two between 512 and 32768. The first
1165** argument should point to an allocation of at least sz*N bytes of memory.
1166** SQLite will use the memory provided by the first argument to satisfy its
1167** memory needs for the first N pages that it adds to cache. If additional
1168** page cache memory is needed beyond what is provided by this option, then
1169** SQLite goes to [sqlite3_malloc()] for the additional storage space.
1170** The implementation might use one or more of the N buffers to hold
1171** memory accounting information. </dd>
1172**
1173** <dt>SQLITE_CONFIG_HEAP</dt>
1174** <dd>This option specifies a static memory buffer that SQLite will use
1175** for all of its dynamic memory allocation needs beyond those provided
1176** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE].
1177** There are three arguments: A pointer to the memory, the number of
1178** bytes in the memory buffer, and the minimum allocation size. If
1179** the first pointer (the memory pointer) is NULL, then SQLite reverts
1180** to using its default memory allocator (the system malloc() implementation),
1181** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. If the
1182** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or
1183** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory
1184** allocator is engaged to handle all of SQLites memory allocation needs.</dd>
1185**
1186** <dt>SQLITE_CONFIG_MUTEX</dt>
1187** <dd>This option takes a single argument which is a pointer to an
1188** instance of the [sqlite3_mutex_methods] structure. The argument specifies
1189** alternative low-level mutex routines to be used in place
1190** the mutex routines built into SQLite.</dd>
1191**
1192** <dt>SQLITE_CONFIG_GETMUTEX</dt>
1193** <dd>This option takes a single argument which is a pointer to an
1194** instance of the [sqlite3_mutex_methods] structure. The
1195** [sqlite3_mutex_methods]
1196** structure is filled with the currently defined mutex routines.
1197** This option can be used to overload the default mutex allocation
1198** routines with a wrapper used to track mutex usage for performance
1199** profiling or testing, for example.</dd>
1200**
1201** <dt>SQLITE_CONFIG_LOOKASIDE</dt>
1202** <dd>This option takes two arguments that determine the default
1203** memory allcation lookaside optimization. The first argument is the
1204** size of each lookaside buffer slot and the second is the number of
1205** slots allocated to each database connection.</dd>
1206**
1207** </dl>
1208*/
1209#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */
1210#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */
1211#define SQLITE_CONFIG_SERIALIZED 3 /* nil */
1212#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */
1213#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */
1214#define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */
1215#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */
1216#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */
1217#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */
1218#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */
1219#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */
1220#define SQLITE_CONFIG_CHUNKALLOC 12 /* int threshold */
1221#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */
1222
1223/*
1224** CAPI3REF: Configuration Options {H10170} <S20000>
1225** EXPERIMENTAL
1226**
1227** These constants are the available integer configuration options that
1228** can be passed as the second argument to the [sqlite3_db_config()] interface.
1229**
1230** New configuration options may be added in future releases of SQLite.
1231** Existing configuration options might be discontinued. Applications
1232** should check the return code from [sqlite3_db_config()] to make sure that
1233** the call worked. The [sqlite3_db_config()] interface will return a
1234** non-zero [error code] if a discontinued or unsupported configuration option
1235** is invoked.
1236**
1237** <dl>
1238** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
1239** <dd>This option takes three additional arguments that determine the
1240** [lookaside memory allocator] configuration for the [database connection].
1241** The first argument (the third parameter to [sqlite3_db_config()] is a
1242** pointer to a memory buffer to use for lookaside memory. The first
1243** argument may be NULL in which case SQLite will allocate the lookaside
1244** buffer itself using [sqlite3_malloc()]. The second argument is the
1245** size of each lookaside buffer slot and the third argument is the number of
1246** slots. The size of the buffer in the first argument must be greater than
1247** or equal to the product of the second and third arguments.</dd>
1248**
1249** </dl>
1250*/
1251#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */
1252
1253
1254/*
1255** CAPI3REF: Enable Or Disable Extended Result Codes {H12200} <S10700>
1256**
1257** The sqlite3_extended_result_codes() routine enables or disables the
1258** [extended result codes] feature of SQLite. The extended result
1259** codes are disabled by default for historical compatibility considerations.
1260**
1261** INVARIANTS:
1262**
1263** {H12201} Each new [database connection] shall have the
1264** [extended result codes] feature disabled by default.
1265**
1266** {H12202} The [sqlite3_extended_result_codes(D,F)] interface shall enable
1267** [extended result codes] for the [database connection] D
1268** if the F parameter is true, or disable them if F is false.
1269*/
1270int sqlite3_extended_result_codes(sqlite3*, int onoff);
1271
1272/*
1273** CAPI3REF: Last Insert Rowid {H12220} <S10700>
1274**
1275** Each entry in an SQLite table has a unique 64-bit signed
1276** integer key called the "rowid". The rowid is always available
1277** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
1278** names are not also used by explicitly declared columns. If
1279** the table has a column of type INTEGER PRIMARY KEY then that column
1280** is another alias for the rowid.
1281**
1282** This routine returns the rowid of the most recent
1283** successful INSERT into the database from the [database connection]
1284** in the first argument. If no successful INSERTs
1285** have ever occurred on that database connection, zero is returned.
1286**
1287** If an INSERT occurs within a trigger, then the rowid of the inserted
1288** row is returned by this routine as long as the trigger is running.
1289** But once the trigger terminates, the value returned by this routine
1290** reverts to the last value inserted before the trigger fired.
1291**
1292** An INSERT that fails due to a constraint violation is not a
1293** successful INSERT and does not change the value returned by this
1294** routine. Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
1295** and INSERT OR ABORT make no changes to the return value of this
1296** routine when their insertion fails. When INSERT OR REPLACE
1297** encounters a constraint violation, it does not fail. The
1298** INSERT continues to completion after deleting rows that caused
1299** the constraint problem so INSERT OR REPLACE will always change
1300** the return value of this interface.
1301**
1302** For the purposes of this routine, an INSERT is considered to
1303** be successful even if it is subsequently rolled back.
1304**
1305** INVARIANTS:
1306**
1307** {H12221} The [sqlite3_last_insert_rowid()] function returns the rowid
1308** of the most recent successful INSERT performed on the same
1309** [database connection] and within the same or higher level
1310** trigger context, or zero if there have been no qualifying inserts.
1311**
1312** {H12223} The [sqlite3_last_insert_rowid()] function returns the
1313** same value when called from the same trigger context
1314** immediately before and after a ROLLBACK.
1315**
1316** ASSUMPTIONS:
1317**
1318** {A12232} If a separate thread performs a new INSERT on the same
1319** database connection while the [sqlite3_last_insert_rowid()]
1320** function is running and thus changes the last insert rowid,
1321** then the value returned by [sqlite3_last_insert_rowid()] is
1322** unpredictable and might not equal either the old or the new
1323** last insert rowid.
1324*/
1325sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);
1326
1327/*
1328** CAPI3REF: Count The Number Of Rows Modified {H12240} <S10600>
1329**
1330** This function returns the number of database rows that were changed
1331** or inserted or deleted by the most recently completed SQL statement
1332** on the [database connection] specified by the first parameter.
1333** Only changes that are directly specified by the INSERT, UPDATE,
1334** or DELETE statement are counted. Auxiliary changes caused by
1335** triggers are not counted. Use the [sqlite3_total_changes()] function
1336** to find the total number of changes including changes caused by triggers.
1337**
1338** A "row change" is a change to a single row of a single table
1339** caused by an INSERT, DELETE, or UPDATE statement. Rows that
1340** are changed as side effects of REPLACE constraint resolution,
1341** rollback, ABORT processing, DROP TABLE, or by any other
1342** mechanisms do not count as direct row changes.
1343**
1344** A "trigger context" is a scope of execution that begins and
1345** ends with the script of a trigger. Most SQL statements are
1346** evaluated outside of any trigger. This is the "top level"
1347** trigger context. If a trigger fires from the top level, a
1348** new trigger context is entered for the duration of that one
1349** trigger. Subtriggers create subcontexts for their duration.
1350**
1351** Calling [sqlite3_exec()] or [sqlite3_step()] recursively does
1352** not create a new trigger context.
1353**
1354** This function returns the number of direct row changes in the
1355** most recent INSERT, UPDATE, or DELETE statement within the same
1356** trigger context.
1357**
1358** Thus, when called from the top level, this function returns the
1359** number of changes in the most recent INSERT, UPDATE, or DELETE
1360** that also occurred at the top level. Within the body of a trigger,
1361** the sqlite3_changes() interface can be called to find the number of
1362** changes in the most recently completed INSERT, UPDATE, or DELETE
1363** statement within the body of the same trigger.
1364** However, the number returned does not include changes
1365** caused by subtriggers since those have their own context.
1366**
1367** SQLite implements the command "DELETE FROM table" without a WHERE clause
1368** by dropping and recreating the table. (This is much faster than going
1369** through and deleting individual elements from the table.) Because of this
1370** optimization, the deletions in "DELETE FROM table" are not row changes and
1371** will not be counted by the sqlite3_changes() or [sqlite3_total_changes()]
1372** functions, regardless of the number of elements that were originally
1373** in the table. To get an accurate count of the number of rows deleted, use
1374** "DELETE FROM table WHERE 1" instead.
1375**
1376** INVARIANTS:
1377**
1378** {H12241} The [sqlite3_changes()] function shall return the number of
1379** row changes caused by the most recent INSERT, UPDATE,
1380** or DELETE statement on the same database connection and
1381** within the same or higher trigger context, or zero if there have
1382** not been any qualifying row changes.
1383**
1384** {H12243} Statements of the form "DELETE FROM tablename" with no
1385** WHERE clause shall cause subsequent calls to
1386** [sqlite3_changes()] to return zero, regardless of the
1387** number of rows originally in the table.
1388**
1389** ASSUMPTIONS:
1390**
1391** {A12252} If a separate thread makes changes on the same database connection
1392** while [sqlite3_changes()] is running then the value returned
1393** is unpredictable and not meaningful.
1394*/
1395int sqlite3_changes(sqlite3*);
1396
1397/*
1398** CAPI3REF: Total Number Of Rows Modified {H12260} <S10600>
1399**
1400** This function returns the number of row changes caused by INSERT,
1401** UPDATE or DELETE statements since the [database connection] was opened.
1402** The count includes all changes from all trigger contexts. However,
1403** the count does not include changes used to implement REPLACE constraints,
1404** do rollbacks or ABORT processing, or DROP table processing.
1405** The changes are counted as soon as the statement that makes them is
1406** completed (when the statement handle is passed to [sqlite3_reset()] or
1407** [sqlite3_finalize()]).
1408**
1409** SQLite implements the command "DELETE FROM table" without a WHERE clause
1410** by dropping and recreating the table. (This is much faster than going
1411** through and deleting individual elements from the table.) Because of this
1412** optimization, the deletions in "DELETE FROM table" are not row changes and
1413** will not be counted by the sqlite3_changes() or [sqlite3_total_changes()]
1414** functions, regardless of the number of elements that were originally
1415** in the table. To get an accurate count of the number of rows deleted, use
1416** "DELETE FROM table WHERE 1" instead.
1417**
1418** See also the [sqlite3_changes()] interface.
1419**
1420** INVARIANTS:
1421**
1422** {H12261} The [sqlite3_total_changes()] returns the total number
1423** of row changes caused by INSERT, UPDATE, and/or DELETE
1424** statements on the same [database connection], in any
1425** trigger context, since the database connection was created.
1426**
1427** {H12263} Statements of the form "DELETE FROM tablename" with no
1428** WHERE clause shall not change the value returned
1429** by [sqlite3_total_changes()].
1430**
1431** ASSUMPTIONS:
1432**
1433** {A12264} If a separate thread makes changes on the same database connection
1434** while [sqlite3_total_changes()] is running then the value
1435** returned is unpredictable and not meaningful.
1436*/
1437int sqlite3_total_changes(sqlite3*);
1438
1439/*
1440** CAPI3REF: Interrupt A Long-Running Query {H12270} <S30500>
1441**
1442** This function causes any pending database operation to abort and
1443** return at its earliest opportunity. This routine is typically
1444** called in response to a user action such as pressing "Cancel"
1445** or Ctrl-C where the user wants a long query operation to halt
1446** immediately.
1447**
1448** It is safe to call this routine from a thread different from the
1449** thread that is currently running the database operation. But it
1450** is not safe to call this routine with a [database connection] that
1451** is closed or might close before sqlite3_interrupt() returns.
1452**
1453** If an SQL operation is very nearly finished at the time when
1454** sqlite3_interrupt() is called, then it might not have an opportunity
1455** to be interrupted and might continue to completion.
1456**
1457** An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
1458** If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
1459** that is inside an explicit transaction, then the entire transaction
1460** will be rolled back automatically.
1461**
1462** A call to sqlite3_interrupt() has no effect on SQL statements
1463** that are started after sqlite3_interrupt() returns.
1464**
1465** INVARIANTS:
1466**
1467** {H12271} The [sqlite3_interrupt()] interface will force all running
1468** SQL statements associated with the same database connection
1469** to halt after processing at most one additional row of data.
1470**
1471** {H12272} Any SQL statement that is interrupted by [sqlite3_interrupt()]
1472** will return [SQLITE_INTERRUPT].
1473**
1474** ASSUMPTIONS:
1475**
1476** {A12279} If the database connection closes while [sqlite3_interrupt()]
1477** is running then bad things will likely happen.
1478*/
1479void sqlite3_interrupt(sqlite3*);
1480
1481/*
1482** CAPI3REF: Determine If An SQL Statement Is Complete {H10510} <S70200>
1483**
1484** These routines are useful for command-line input to determine if the
1485** currently entered text seems to form complete a SQL statement or
1486** if additional input is needed before sending the text into
1487** SQLite for parsing. These routines return true if the input string
1488** appears to be a complete SQL statement. A statement is judged to be
1489** complete if it ends with a semicolon token and is not a fragment of a
1490** CREATE TRIGGER statement. Semicolons that are embedded within
1491** string literals or quoted identifier names or comments are not
1492** independent tokens (they are part of the token in which they are
1493** embedded) and thus do not count as a statement terminator.
1494**
1495** These routines do not parse the SQL statements thus
1496** will not detect syntactically incorrect SQL.
1497**
1498** INVARIANTS:
1499**
1500** {H10511} A successful evaluation of [sqlite3_complete()] or
1501** [sqlite3_complete16()] functions shall
1502** return a numeric 1 if and only if the last non-whitespace
1503** token in their input is a semicolon that is not in between
1504** the BEGIN and END of a CREATE TRIGGER statement.
1505**
1506** {H10512} If a memory allocation error occurs during an invocation
1507** of [sqlite3_complete()] or [sqlite3_complete16()] then the
1508** routine shall return [SQLITE_NOMEM].
1509**
1510** ASSUMPTIONS:
1511**
1512** {A10512} The input to [sqlite3_complete()] must be a zero-terminated
1513** UTF-8 string.
1514**
1515** {A10513} The input to [sqlite3_complete16()] must be a zero-terminated
1516** UTF-16 string in native byte order.
1517*/
1518int sqlite3_complete(const char *sql);
1519int sqlite3_complete16(const void *sql);
1520
1521/*
1522** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors {H12310} <S40400>
1523**
1524** This routine sets a callback function that might be invoked whenever
1525** an attempt is made to open a database table that another thread
1526** or process has locked.
1527**
1528** If the busy callback is NULL, then [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]
1529** is returned immediately upon encountering the lock. If the busy callback
1530** is not NULL, then the callback will be invoked with two arguments.
1531**
1532** The first argument to the handler is a copy of the void* pointer which
1533** is the third argument to sqlite3_busy_handler(). The second argument to
1534** the handler callback is the number of times that the busy handler has
1535** been invoked for this locking event. If the
1536** busy callback returns 0, then no additional attempts are made to
1537** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned.
1538** If the callback returns non-zero, then another attempt
1539** is made to open the database for reading and the cycle repeats.
1540**
1541** The presence of a busy handler does not guarantee that it will be invoked
1542** when there is lock contention. If SQLite determines that invoking the busy
1543** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
1544** or [SQLITE_IOERR_BLOCKED] instead of invoking the busy handler.
1545** Consider a scenario where one process is holding a read lock that
1546** it is trying to promote to a reserved lock and
1547** a second process is holding a reserved lock that it is trying
1548** to promote to an exclusive lock. The first process cannot proceed
1549** because it is blocked by the second and the second process cannot
1550** proceed because it is blocked by the first. If both processes
1551** invoke the busy handlers, neither will make any progress. Therefore,
1552** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
1553** will induce the first process to release its read lock and allow
1554** the second process to proceed.
1555**
1556** The default busy callback is NULL.
1557**
1558** The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED]
1559** when SQLite is in the middle of a large transaction where all the
1560** changes will not fit into the in-memory cache. SQLite will
1561** already hold a RESERVED lock on the database file, but it needs
1562** to promote this lock to EXCLUSIVE so that it can spill cache
1563** pages into the database file without harm to concurrent
1564** readers. If it is unable to promote the lock, then the in-memory
1565** cache will be left in an inconsistent state and so the error
1566** code is promoted from the relatively benign [SQLITE_BUSY] to
1567** the more severe [SQLITE_IOERR_BLOCKED]. This error code promotion
1568** forces an automatic rollback of the changes. See the
1569** <a href="/cvstrac/wiki?p=CorruptionFollowingBusyError">
1570** CorruptionFollowingBusyError</a> wiki page for a discussion of why
1571** this is important.
1572**
1573** There can only be a single busy handler defined for each
1574** [database connection]. Setting a new busy handler clears any
1575** previously set handler. Note that calling [sqlite3_busy_timeout()]
1576** will also set or clear the busy handler.
1577**
1578** INVARIANTS:
1579**
1580** {H12311} The [sqlite3_busy_handler(D,C,A)] function shall replace
1581** busy callback in the [database connection] D with a new
1582** a new busy handler C and application data pointer A.
1583**
1584** {H12312} Newly created [database connections] shall have a busy
1585** handler of NULL.
1586**
1587** {H12314} When two or more [database connections] share a
1588** [sqlite3_enable_shared_cache | common cache],
1589** the busy handler for the database connection currently using
1590** the cache shall be invoked when the cache encounters a lock.
1591**
1592** {H12316} If a busy handler callback returns zero, then the SQLite interface
1593** that provoked the locking event shall return [SQLITE_BUSY].
1594**
1595** {H12318} SQLite shall invokes the busy handler with two arguments which
1596** are a copy of the pointer supplied by the 3rd parameter to
1597** [sqlite3_busy_handler()] and a count of the number of prior
1598** invocations of the busy handler for the same locking event.
1599**
1600** ASSUMPTIONS:
1601**
1602** {A12319} A busy handler must not close the database connection
1603** or [prepared statement] that invoked the busy handler.
1604*/
1605int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*);
1606
1607/*
1608** CAPI3REF: Set A Busy Timeout {H12340} <S40410>
1609**
1610** This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
1611** for a specified amount of time when a table is locked. The handler
1612** will sleep multiple times until at least "ms" milliseconds of sleeping
1613** have accumulated. {H12343} After "ms" milliseconds of sleeping,
1614** the handler returns 0 which causes [sqlite3_step()] to return
1615** [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED].
1616**
1617** Calling this routine with an argument less than or equal to zero
1618** turns off all busy handlers.
1619**
1620** There can only be a single busy handler for a particular
1621** [database connection] any any given moment. If another busy handler
1622** was defined (using [sqlite3_busy_handler()]) prior to calling
1623** this routine, that other busy handler is cleared.
1624**
1625** INVARIANTS:
1626**
1627** {H12341} The [sqlite3_busy_timeout()] function shall override any prior
1628** [sqlite3_busy_timeout()] or [sqlite3_busy_handler()] setting
1629** on the same [database connection].
1630**
1631** {H12343} If the 2nd parameter to [sqlite3_busy_timeout()] is less than
1632** or equal to zero, then the busy handler shall be cleared so that
1633** all subsequent locking events immediately return [SQLITE_BUSY].
1634**
1635** {H12344} If the 2nd parameter to [sqlite3_busy_timeout()] is a positive
1636** number N, then a busy handler shall be set that repeatedly calls
1637** the xSleep() method in the [sqlite3_vfs | VFS interface] until
1638** either the lock clears or until the cumulative sleep time
1639** reported back by xSleep() exceeds N milliseconds.
1640*/
1641int sqlite3_busy_timeout(sqlite3*, int ms);
1642
1643/*
1644** CAPI3REF: Convenience Routines For Running Queries {H12370} <S10000>
1645**
1646** Definition: A <b>result table</b> is memory data structure created by the
1647** [sqlite3_get_table()] interface. A result table records the
1648** complete query results from one or more queries.
1649**
1650** The table conceptually has a number of rows and columns. But
1651** these numbers are not part of the result table itself. These
1652** numbers are obtained separately. Let N be the number of rows
1653** and M be the number of columns.
1654**
1655** A result table is an array of pointers to zero-terminated UTF-8 strings.
1656** There are (N+1)*M elements in the array. The first M pointers point
1657** to zero-terminated strings that contain the names of the columns.
1658** The remaining entries all point to query results. NULL values result
1659** in NULL pointers. All other values are in their UTF-8 zero-terminated
1660** string representation as returned by [sqlite3_column_text()].
1661**
1662** A result table might consist of one or more memory allocations.
1663** It is not safe to pass a result table directly to [sqlite3_free()].
1664** A result table should be deallocated using [sqlite3_free_table()].
1665**
1666** As an example of the result table format, suppose a query result
1667** is as follows:
1668**
1669** <blockquote><pre>
1670** Name | Age
1671** -----------------------
1672** Alice | 43
1673** Bob | 28
1674** Cindy | 21
1675** </pre></blockquote>
1676**
1677** There are two column (M==2) and three rows (N==3). Thus the
1678** result table has 8 entries. Suppose the result table is stored
1679** in an array names azResult. Then azResult holds this content:
1680**
1681** <blockquote><pre>
1682** azResult&#91;0] = "Name";
1683** azResult&#91;1] = "Age";
1684** azResult&#91;2] = "Alice";
1685** azResult&#91;3] = "43";
1686** azResult&#91;4] = "Bob";
1687** azResult&#91;5] = "28";
1688** azResult&#91;6] = "Cindy";
1689** azResult&#91;7] = "21";
1690** </pre></blockquote>
1691**
1692** The sqlite3_get_table() function evaluates one or more
1693** semicolon-separated SQL statements in the zero-terminated UTF-8
1694** string of its 2nd parameter. It returns a result table to the
1695** pointer given in its 3rd parameter.
1696**
1697** After the calling function has finished using the result, it should
1698** pass the pointer to the result table to sqlite3_free_table() in order to
1699** release the memory that was malloced. Because of the way the
1700** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
1701** function must not try to call [sqlite3_free()] directly. Only
1702** [sqlite3_free_table()] is able to release the memory properly and safely.
1703**
1704** The sqlite3_get_table() interface is implemented as a wrapper around
1705** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access
1706** to any internal data structures of SQLite. It uses only the public
1707** interface defined here. As a consequence, errors that occur in the
1708** wrapper layer outside of the internal [sqlite3_exec()] call are not
1709** reflected in subsequent calls to [sqlite3_errcode()] or [sqlite3_errmsg()].
1710**
1711** INVARIANTS:
1712**
1713** {H12371} If a [sqlite3_get_table()] fails a memory allocation, then
1714** it shall free the result table under construction, abort the
1715** query in process, skip any subsequent queries, set the
1716** *pazResult output pointer to NULL and return [SQLITE_NOMEM].
1717**
1718** {H12373} If the pnColumn parameter to [sqlite3_get_table()] is not NULL
1719** then a successful invocation of [sqlite3_get_table()] shall
1720** write the number of columns in the
1721** result set of the query into *pnColumn.
1722**
1723** {H12374} If the pnRow parameter to [sqlite3_get_table()] is not NULL
1724** then a successful invocation of [sqlite3_get_table()] shall
1725** writes the number of rows in the
1726** result set of the query into *pnRow.
1727**
1728** {H12376} A successful invocation of [sqlite3_get_table()] that computes
1729** N rows of result with C columns per row shall make *pazResult
1730** point to an array of pointers to (N+1)*C strings where the first
1731** C strings are column names as obtained from
1732** [sqlite3_column_name()] and the rest are column result values
1733** obtained from [sqlite3_column_text()].
1734**
1735** {H12379} The values in the pazResult array returned by [sqlite3_get_table()]
1736** shall remain valid until cleared by [sqlite3_free_table()].
1737**
1738** {H12382} When an error occurs during evaluation of [sqlite3_get_table()]
1739** the function shall set *pazResult to NULL, write an error message
1740** into memory obtained from [sqlite3_malloc()], make
1741** **pzErrmsg point to that error message, and return a
1742** appropriate [error code].
1743*/
1744int sqlite3_get_table(
1745 sqlite3 *db, /* An open database */
1746 const char *zSql, /* SQL to be evaluated */
1747 char ***pazResult, /* Results of the query */
1748 int *pnRow, /* Number of result rows written here */
1749 int *pnColumn, /* Number of result columns written here */
1750 char **pzErrmsg /* Error msg written here */
1751);
1752void sqlite3_free_table(char **result);
1753
1754/*
1755** CAPI3REF: Formatted String Printing Functions {H17400} <S70000><S20000>
1756**
1757** These routines are workalikes of the "printf()" family of functions
1758** from the standard C library.
1759**
1760** The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
1761** results into memory obtained from [sqlite3_malloc()].
1762** The strings returned by these two routines should be
1763** released by [sqlite3_free()]. Both routines return a
1764** NULL pointer if [sqlite3_malloc()] is unable to allocate enough
1765** memory to hold the resulting string.
1766**
1767** In sqlite3_snprintf() routine is similar to "snprintf()" from
1768** the standard C library. The result is written into the
1769** buffer supplied as the second parameter whose size is given by
1770** the first parameter. Note that the order of the
1771** first two parameters is reversed from snprintf(). This is an
1772** historical accident that cannot be fixed without breaking
1773** backwards compatibility. Note also that sqlite3_snprintf()
1774** returns a pointer to its buffer instead of the number of
1775** characters actually written into the buffer. We admit that
1776** the number of characters written would be a more useful return
1777** value but we cannot change the implementation of sqlite3_snprintf()
1778** now without breaking compatibility.
1779**
1780** As long as the buffer size is greater than zero, sqlite3_snprintf()
1781** guarantees that the buffer is always zero-terminated. The first
1782** parameter "n" is the total size of the buffer, including space for
1783** the zero terminator. So the longest string that can be completely
1784** written will be n-1 characters.
1785**
1786** These routines all implement some additional formatting
1787** options that are useful for constructing SQL statements.
1788** All of the usual printf() formatting options apply. In addition, there
1789** is are "%q", "%Q", and "%z" options.
1790**
1791** The %q option works like %s in that it substitutes a null-terminated
1792** string from the argument list. But %q also doubles every '\'' character.
1793** %q is designed for use inside a string literal. By doubling each '\''
1794** character it escapes that character and allows it to be inserted into
1795** the string.
1796**
1797** For example, assume the string variable zText contains text as follows:
1798**
1799** <blockquote><pre>
1800** char *zText = "It's a happy day!";
1801** </pre></blockquote>
1802**
1803** One can use this text in an SQL statement as follows:
1804**
1805** <blockquote><pre>
1806** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText);
1807** sqlite3_exec(db, zSQL, 0, 0, 0);
1808** sqlite3_free(zSQL);
1809** </pre></blockquote>
1810**
1811** Because the %q format string is used, the '\'' character in zText
1812** is escaped and the SQL generated is as follows:
1813**
1814** <blockquote><pre>
1815** INSERT INTO table1 VALUES('It''s a happy day!')
1816** </pre></blockquote>
1817**
1818** This is correct. Had we used %s instead of %q, the generated SQL
1819** would have looked like this:
1820**
1821** <blockquote><pre>
1822** INSERT INTO table1 VALUES('It's a happy day!');
1823** </pre></blockquote>
1824**
1825** This second example is an SQL syntax error. As a general rule you should
1826** always use %q instead of %s when inserting text into a string literal.
1827**
1828** The %Q option works like %q except it also adds single quotes around
1829** the outside of the total string. Additionally, if the parameter in the
1830** argument list is a NULL pointer, %Q substitutes the text "NULL" (without
1831** single quotes) in place of the %Q option. So, for example, one could say:
1832**
1833** <blockquote><pre>
1834** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText);
1835** sqlite3_exec(db, zSQL, 0, 0, 0);
1836** sqlite3_free(zSQL);
1837** </pre></blockquote>
1838**
1839** The code above will render a correct SQL statement in the zSQL
1840** variable even if the zText variable is a NULL pointer.
1841**
1842** The "%z" formatting option works exactly like "%s" with the
1843** addition that after the string has been read and copied into
1844** the result, [sqlite3_free()] is called on the input string. {END}
1845**
1846** INVARIANTS:
1847**
1848** {H17403} The [sqlite3_mprintf()] and [sqlite3_vmprintf()] interfaces
1849** return either pointers to zero-terminated UTF-8 strings held in
1850** memory obtained from [sqlite3_malloc()] or NULL pointers if
1851** a call to [sqlite3_malloc()] fails.
1852**
1853** {H17406} The [sqlite3_snprintf()] interface writes a zero-terminated
1854** UTF-8 string into the buffer pointed to by the second parameter
1855** provided that the first parameter is greater than zero.
1856**
1857** {H17407} The [sqlite3_snprintf()] interface does not write slots of
1858** its output buffer (the second parameter) outside the range
1859** of 0 through N-1 (where N is the first parameter)
1860** regardless of the length of the string
1861** requested by the format specification.
1862*/
1863char *sqlite3_mprintf(const char*,...);
1864char *sqlite3_vmprintf(const char*, va_list);
1865char *sqlite3_snprintf(int,char*,const char*, ...);
1866
1867/*
1868** CAPI3REF: Memory Allocation Subsystem {H17300} <S20000>
1869**
1870** The SQLite core uses these three routines for all of its own
1871** internal memory allocation needs. "Core" in the previous sentence
1872** does not include operating-system specific VFS implementation. The
1873** Windows VFS uses native malloc() and free() for some operations.
1874**
1875** The sqlite3_malloc() routine returns a pointer to a block
1876** of memory at least N bytes in length, where N is the parameter.
1877** If sqlite3_malloc() is unable to obtain sufficient free
1878** memory, it returns a NULL pointer. If the parameter N to
1879** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
1880** a NULL pointer.
1881**
1882** Calling sqlite3_free() with a pointer previously returned
1883** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
1884** that it might be reused. The sqlite3_free() routine is
1885** a no-op if is called with a NULL pointer. Passing a NULL pointer
1886** to sqlite3_free() is harmless. After being freed, memory
1887** should neither be read nor written. Even reading previously freed
1888** memory might result in a segmentation fault or other severe error.
1889** Memory corruption, a segmentation fault, or other severe error
1890** might result if sqlite3_free() is called with a non-NULL pointer that
1891** was not obtained from sqlite3_malloc() or sqlite3_free().
1892**
1893** The sqlite3_realloc() interface attempts to resize a
1894** prior memory allocation to be at least N bytes, where N is the
1895** second parameter. The memory allocation to be resized is the first
1896** parameter. If the first parameter to sqlite3_realloc()
1897** is a NULL pointer then its behavior is identical to calling
1898** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc().
1899** If the second parameter to sqlite3_realloc() is zero or
1900** negative then the behavior is exactly the same as calling
1901** sqlite3_free(P) where P is the first parameter to sqlite3_realloc().
1902** sqlite3_realloc() returns a pointer to a memory allocation
1903** of at least N bytes in size or NULL if sufficient memory is unavailable.
1904** If M is the size of the prior allocation, then min(N,M) bytes
1905** of the prior allocation are copied into the beginning of buffer returned
1906** by sqlite3_realloc() and the prior allocation is freed.
1907** If sqlite3_realloc() returns NULL, then the prior allocation
1908** is not freed.
1909**
1910** The memory returned by sqlite3_malloc() and sqlite3_realloc()
1911** is always aligned to at least an 8 byte boundary. {END}
1912**
1913** The default implementation of the memory allocation subsystem uses
1914** the malloc(), realloc() and free() provided by the standard C library.
1915** {H17382} However, if SQLite is compiled with the
1916** SQLITE_MEMORY_SIZE=<i>NNN</i> C preprocessor macro (where <i>NNN</i>
1917** is an integer), then SQLite create a static array of at least
1918** <i>NNN</i> bytes in size and uses that array for all of its dynamic
1919** memory allocation needs. {END} Additional memory allocator options
1920** may be added in future releases.
1921**
1922** In SQLite version 3.5.0 and 3.5.1, it was possible to define
1923** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in
1924** implementation of these routines to be omitted. That capability
1925** is no longer provided. Only built-in memory allocators can be used.
1926**
1927** The Windows OS interface layer calls
1928** the system malloc() and free() directly when converting
1929** filenames between the UTF-8 encoding used by SQLite
1930** and whatever filename encoding is used by the particular Windows
1931** installation. Memory allocation errors are detected, but
1932** they are reported back as [SQLITE_CANTOPEN] or
1933** [SQLITE_IOERR] rather than [SQLITE_NOMEM].
1934**
1935** INVARIANTS:
1936**
1937** {H17303} The [sqlite3_malloc(N)] interface returns either a pointer to
1938** a newly checked-out block of at least N bytes of memory
1939** that is 8-byte aligned, or it returns NULL if it is unable
1940** to fulfill the request.
1941**
1942** {H17304} The [sqlite3_malloc(N)] interface returns a NULL pointer if
1943** N is less than or equal to zero.
1944**
1945** {H17305} The [sqlite3_free(P)] interface releases memory previously
1946** returned from [sqlite3_malloc()] or [sqlite3_realloc()],
1947** making it available for reuse.
1948**
1949** {H17306} A call to [sqlite3_free(NULL)] is a harmless no-op.
1950**
1951** {H17310} A call to [sqlite3_realloc(0,N)] is equivalent to a call
1952** to [sqlite3_malloc(N)].
1953**
1954** {H17312} A call to [sqlite3_realloc(P,0)] is equivalent to a call
1955** to [sqlite3_free(P)].
1956**
1957** {H17315} The SQLite core uses [sqlite3_malloc()], [sqlite3_realloc()],
1958** and [sqlite3_free()] for all of its memory allocation and
1959** deallocation needs.
1960**
1961** {H17318} The [sqlite3_realloc(P,N)] interface returns either a pointer
1962** to a block of checked-out memory of at least N bytes in size
1963** that is 8-byte aligned, or a NULL pointer.
1964**
1965** {H17321} When [sqlite3_realloc(P,N)] returns a non-NULL pointer, it first
1966** copies the first K bytes of content from P into the newly
1967** allocated block, where K is the lesser of N and the size of
1968** the buffer P.
1969**
1970** {H17322} When [sqlite3_realloc(P,N)] returns a non-NULL pointer, it first
1971** releases the buffer P.
1972**
1973** {H17323} When [sqlite3_realloc(P,N)] returns NULL, the buffer P is
1974** not modified or released.
1975**
1976** ASSUMPTIONS:
1977**
1978** {A17350} The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
1979** must be either NULL or else pointers obtained from a prior
1980** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
1981** not yet been released.
1982**
1983** {A17351} The application must not read or write any part of
1984** a block of memory after it has been released using
1985** [sqlite3_free()] or [sqlite3_realloc()].
1986*/
1987void *sqlite3_malloc(int);
1988void *sqlite3_realloc(void*, int);
1989void sqlite3_free(void*);
1990
1991/*
1992** CAPI3REF: Memory Allocator Statistics {H17370} <S30210>
1993**
1994** SQLite provides these two interfaces for reporting on the status
1995** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
1996** routines, which form the built-in memory allocation subsystem.
1997**
1998** INVARIANTS:
1999**
2000** {H17371} The [sqlite3_memory_used()] routine returns the number of bytes
2001** of memory currently outstanding (malloced but not freed).
2002**
2003** {H17373} The [sqlite3_memory_highwater()] routine returns the maximum
2004** value of [sqlite3_memory_used()] since the high-water mark
2005** was last reset.
2006**
2007** {H17374} The values returned by [sqlite3_memory_used()] and
2008** [sqlite3_memory_highwater()] include any overhead
2009** added by SQLite in its implementation of [sqlite3_malloc()],
2010** but not overhead added by the any underlying system library
2011** routines that [sqlite3_malloc()] may call.
2012**
2013** {H17375} The memory high-water mark is reset to the current value of
2014** [sqlite3_memory_used()] if and only if the parameter to
2015** [sqlite3_memory_highwater()] is true. The value returned
2016** by [sqlite3_memory_highwater(1)] is the high-water mark
2017** prior to the reset.
2018*/
2019sqlite3_int64 sqlite3_memory_used(void);
2020sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
2021
2022/*
2023** CAPI3REF: Pseudo-Random Number Generator {H17390} <S20000>
2024**
2025** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
2026** select random ROWIDs when inserting new records into a table that
2027** already uses the largest possible ROWID. The PRNG is also used for
2028** the build-in random() and randomblob() SQL functions. This interface allows
2029** applications to access the same PRNG for other purposes.
2030**
2031** A call to this routine stores N bytes of randomness into buffer P.
2032**
2033** The first time this routine is invoked (either internally or by
2034** the application) the PRNG is seeded using randomness obtained
2035** from the xRandomness method of the default [sqlite3_vfs] object.
2036** On all subsequent invocations, the pseudo-randomness is generated
2037** internally and without recourse to the [sqlite3_vfs] xRandomness
2038** method.
2039**
2040** INVARIANTS:
2041**
2042** {H17392} The [sqlite3_randomness(N,P)] interface writes N bytes of
2043** high-quality pseudo-randomness into buffer P.
2044*/
2045void sqlite3_randomness(int N, void *P);
2046
2047/*
2048** CAPI3REF: Compile-Time Authorization Callbacks {H12500} <S70100>
2049**
2050** This routine registers a authorizer callback with a particular
2051** [database connection], supplied in the first argument.
2052** The authorizer callback is invoked as SQL statements are being compiled
2053** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
2054** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. At various
2055** points during the compilation process, as logic is being created
2056** to perform various actions, the authorizer callback is invoked to
2057** see if those actions are allowed. The authorizer callback should
2058** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
2059** specific action but allow the SQL statement to continue to be
2060** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
2061** rejected with an error. If the authorizer callback returns
2062** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
2063** then the [sqlite3_prepare_v2()] or equivalent call that triggered
2064** the authorizer will fail with an error message.
2065**
2066** When the callback returns [SQLITE_OK], that means the operation
2067** requested is ok. When the callback returns [SQLITE_DENY], the
2068** [sqlite3_prepare_v2()] or equivalent call that triggered the
2069** authorizer will fail with an error message explaining that
2070** access is denied. If the authorizer code is [SQLITE_READ]
2071** and the callback returns [SQLITE_IGNORE] then the
2072** [prepared statement] statement is constructed to substitute
2073** a NULL value in place of the table column that would have
2074** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE]
2075** return can be used to deny an untrusted user access to individual
2076** columns of a table.
2077**
2078** The first parameter to the authorizer callback is a copy of the third
2079** parameter to the sqlite3_set_authorizer() interface. The second parameter
2080** to the callback is an integer [SQLITE_COPY | action code] that specifies
2081** the particular action to be authorized. The third through sixth parameters
2082** to the callback are zero-terminated strings that contain additional
2083** details about the action to be authorized.
2084**
2085** An authorizer is used when [sqlite3_prepare | preparing]
2086** SQL statements from an untrusted source, to ensure that the SQL statements
2087** do not try to access data they are not allowed to see, or that they do not
2088** try to execute malicious statements that damage the database. For
2089** example, an application may allow a user to enter arbitrary
2090** SQL queries for evaluation by a database. But the application does
2091** not want the user to be able to make arbitrary changes to the
2092** database. An authorizer could then be put in place while the
2093** user-entered SQL is being [sqlite3_prepare | prepared] that
2094** disallows everything except [SELECT] statements.
2095**
2096** Applications that need to process SQL from untrusted sources
2097** might also consider lowering resource limits using [sqlite3_limit()]
2098** and limiting database size using the [max_page_count] [PRAGMA]
2099** in addition to using an authorizer.
2100**
2101** Only a single authorizer can be in place on a database connection
2102** at a time. Each call to sqlite3_set_authorizer overrides the
2103** previous call. Disable the authorizer by installing a NULL callback.
2104** The authorizer is disabled by default.
2105**
2106** When [sqlite3_prepare_v2()] is used to prepare a statement, the
2107** statement might be reprepared during [sqlite3_step()] due to a
2108** schema change. Hence, the application should ensure that the
2109** correct authorizer callback remains in place during the [sqlite3_step()].
2110**
2111** Note that the authorizer callback is invoked only during
2112** [sqlite3_prepare()] or its variants. Authorization is not
2113** performed during statement evaluation in [sqlite3_step()].
2114**
2115** INVARIANTS:
2116**
2117** {H12501} The [sqlite3_set_authorizer(D,...)] interface registers a
2118** authorizer callback with database connection D.
2119**
2120** {H12502} The authorizer callback is invoked as SQL statements are
2121** being parseed and compiled.
2122**
2123** {H12503} If the authorizer callback returns any value other than
2124** [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY], then
2125** the application interface call that caused
2126** the authorizer callback to run shall fail with an
2127** [SQLITE_ERROR] error code and an appropriate error message.
2128**
2129** {H12504} When the authorizer callback returns [SQLITE_OK], the operation
2130** described is processed normally.
2131**
2132** {H12505} When the authorizer callback returns [SQLITE_DENY], the
2133** application interface call that caused the
2134** authorizer callback to run shall fail
2135** with an [SQLITE_ERROR] error code and an error message
2136** explaining that access is denied.
2137**
2138** {H12506} If the authorizer code (the 2nd parameter to the authorizer
2139** callback) is [SQLITE_READ] and the authorizer callback returns
2140** [SQLITE_IGNORE], then the prepared statement is constructed to
2141** insert a NULL value in place of the table column that would have
2142** been read if [SQLITE_OK] had been returned.
2143**
2144** {H12507} If the authorizer code (the 2nd parameter to the authorizer
2145** callback) is anything other than [SQLITE_READ], then
2146** a return of [SQLITE_IGNORE] has the same effect as [SQLITE_DENY].
2147**
2148** {H12510} The first parameter to the authorizer callback is a copy of
2149** the third parameter to the [sqlite3_set_authorizer()] interface.
2150**
2151** {H12511} The second parameter to the callback is an integer
2152** [SQLITE_COPY | action code] that specifies the particular action
2153** to be authorized.
2154**
2155** {H12512} The third through sixth parameters to the callback are
2156** zero-terminated strings that contain
2157** additional details about the action to be authorized.
2158**
2159** {H12520} Each call to [sqlite3_set_authorizer()] overrides
2160** any previously installed authorizer.
2161**
2162** {H12521} A NULL authorizer means that no authorization
2163** callback is invoked.
2164**
2165** {H12522} The default authorizer is NULL.
2166*/
2167int sqlite3_set_authorizer(
2168 sqlite3*,
2169 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
2170 void *pUserData
2171);
2172
2173/*
2174** CAPI3REF: Authorizer Return Codes {H12590} <H12500>
2175**
2176** The [sqlite3_set_authorizer | authorizer callback function] must
2177** return either [SQLITE_OK] or one of these two constants in order
2178** to signal SQLite whether or not the action is permitted. See the
2179** [sqlite3_set_authorizer | authorizer documentation] for additional
2180** information.
2181*/
2182#define SQLITE_DENY 1 /* Abort the SQL statement with an error */
2183#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */
2184
2185/*
2186** CAPI3REF: Authorizer Action Codes {H12550} <H12500>
2187**
2188** The [sqlite3_set_authorizer()] interface registers a callback function
2189** that is invoked to authorize certain SQL statement actions. The
2190** second parameter to the callback is an integer code that specifies
2191** what action is being authorized. These are the integer action codes that
2192** the authorizer callback may be passed.
2193**
2194** These action code values signify what kind of operation is to be
2195** authorized. The 3rd and 4th parameters to the authorization
2196** callback function will be parameters or NULL depending on which of these
2197** codes is used as the second parameter. The 5th parameter to the
2198** authorizer callback is the name of the database ("main", "temp",
2199** etc.) if applicable. The 6th parameter to the authorizer callback
2200** is the name of the inner-most trigger or view that is responsible for
2201** the access attempt or NULL if this access attempt is directly from
2202** top-level SQL code.
2203**
2204** INVARIANTS:
2205**
2206** {H12551} The second parameter to an
2207** [sqlite3_set_authorizer | authorizer callback] shall be an integer
2208** [SQLITE_COPY | authorizer code] that specifies what action
2209** is being authorized.
2210**
2211** {H12552} The 3rd and 4th parameters to the
2212** [sqlite3_set_authorizer | authorization callback]
2213** shall be parameters or NULL depending on which
2214** [SQLITE_COPY | authorizer code] is used as the second parameter.
2215**
2216** {H12553} The 5th parameter to the
2217** [sqlite3_set_authorizer | authorizer callback] shall be the name
2218** of the database (example: "main", "temp", etc.) if applicable.
2219**
2220** {H12554} The 6th parameter to the
2221** [sqlite3_set_authorizer | authorizer callback] shall be the name
2222** of the inner-most trigger or view that is responsible for
2223** the access attempt or NULL if this access attempt is directly from
2224** top-level SQL code.
2225*/
2226/******************************************* 3rd ************ 4th ***********/
2227#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */
2228#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */
2229#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */
2230#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */
2231#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */
2232#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */
2233#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */
2234#define SQLITE_CREATE_VIEW 8 /* View Name NULL */
2235#define SQLITE_DELETE 9 /* Table Name NULL */
2236#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */
2237#define SQLITE_DROP_TABLE 11 /* Table Name NULL */
2238#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */
2239#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */
2240#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */
2241#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */
2242#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */
2243#define SQLITE_DROP_VIEW 17 /* View Name NULL */
2244#define SQLITE_INSERT 18 /* Table Name NULL */
2245#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */
2246#define SQLITE_READ 20 /* Table Name Column Name */
2247#define SQLITE_SELECT 21 /* NULL NULL */
2248#define SQLITE_TRANSACTION 22 /* NULL NULL */
2249#define SQLITE_UPDATE 23 /* Table Name Column Name */
2250#define SQLITE_ATTACH 24 /* Filename NULL */
2251#define SQLITE_DETACH 25 /* Database Name NULL */
2252#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */
2253#define SQLITE_REINDEX 27 /* Index Name NULL */
2254#define SQLITE_ANALYZE 28 /* Table Name NULL */
2255#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */
2256#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */
2257#define SQLITE_FUNCTION 31 /* Function Name NULL */
2258#define SQLITE_COPY 0 /* No longer used */
2259
2260/*
2261** CAPI3REF: Tracing And Profiling Functions {H12280} <S60400>
2262** EXPERIMENTAL
2263**
2264** These routines register callback functions that can be used for
2265** tracing and profiling the execution of SQL statements.
2266**
2267** The callback function registered by sqlite3_trace() is invoked at
2268** various times when an SQL statement is being run by [sqlite3_step()].
2269** The callback returns a UTF-8 rendering of the SQL statement text
2270** as the statement first begins executing. Additional callbacks occur
2271** as each triggered subprogram is entered. The callbacks for triggers
2272** contain a UTF-8 SQL comment that identifies the trigger.
2273**
2274** The callback function registered by sqlite3_profile() is invoked
2275** as each SQL statement finishes. The profile callback contains
2276** the original statement text and an estimate of wall-clock time
2277** of how long that statement took to run.
2278**
2279** INVARIANTS:
2280**
2281** {H12281} The callback function registered by [sqlite3_trace()]
2282** shall be invoked
2283** whenever an SQL statement first begins to execute and
2284** whenever a trigger subprogram first begins to run.
2285**
2286** {H12282} Each call to [sqlite3_trace()] shall override the previously
2287** registered trace callback.
2288**
2289** {H12283} A NULL trace callback shall disable tracing.
2290**
2291** {H12284} The first argument to the trace callback shall be a copy of
2292** the pointer which was the 3rd argument to [sqlite3_trace()].
2293**
2294** {H12285} The second argument to the trace callback is a
2295** zero-terminated UTF-8 string containing the original text
2296** of the SQL statement as it was passed into [sqlite3_prepare_v2()]
2297** or the equivalent, or an SQL comment indicating the beginning
2298** of a trigger subprogram.
2299**
2300** {H12287} The callback function registered by [sqlite3_profile()] is invoked
2301** as each SQL statement finishes.
2302**
2303** {H12288} The first parameter to the profile callback is a copy of
2304** the 3rd parameter to [sqlite3_profile()].
2305**
2306** {H12289} The second parameter to the profile callback is a
2307** zero-terminated UTF-8 string that contains the complete text of
2308** the SQL statement as it was processed by [sqlite3_prepare_v2()]
2309** or the equivalent.
2310**
2311** {H12290} The third parameter to the profile callback is an estimate
2312** of the number of nanoseconds of wall-clock time required to
2313** run the SQL statement from start to finish.
2314*/
2315SQLITE_EXPERIMENTAL void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*);
2316SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*,
2317 void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
2318
2319/*
2320** CAPI3REF: Query Progress Callbacks {H12910} <S60400>
2321**
2322** This routine configures a callback function - the
2323** progress callback - that is invoked periodically during long
2324** running calls to [sqlite3_exec()], [sqlite3_step()] and
2325** [sqlite3_get_table()]. An example use for this
2326** interface is to keep a GUI updated during a large query.
2327**
2328** If the progress callback returns non-zero, the operation is
2329** interrupted. This feature can be used to implement a
2330** "Cancel" button on a GUI dialog box.
2331**
2332** INVARIANTS:
2333**
2334** {H12911} The callback function registered by sqlite3_progress_handler()
2335** is invoked periodically during long running calls to
2336** [sqlite3_step()].
2337**
2338** {H12912} The progress callback is invoked once for every N virtual
2339** machine opcodes, where N is the second argument to
2340** the [sqlite3_progress_handler()] call that registered
2341** the callback. If N is less than 1, sqlite3_progress_handler()
2342** acts as if a NULL progress handler had been specified.
2343**
2344** {H12913} The progress callback itself is identified by the third
2345** argument to sqlite3_progress_handler().
2346**
2347** {H12914} The fourth argument to sqlite3_progress_handler() is a
2348** void pointer passed to the progress callback
2349** function each time it is invoked.
2350**
2351** {H12915} If a call to [sqlite3_step()] results in fewer than N opcodes
2352** being executed, then the progress callback is never invoked.
2353**
2354** {H12916} Every call to [sqlite3_progress_handler()]
2355** overwrites any previously registered progress handler.
2356**
2357** {H12917} If the progress handler callback is NULL then no progress
2358** handler is invoked.
2359**
2360** {H12918} If the progress callback returns a result other than 0, then
2361** the behavior is a if [sqlite3_interrupt()] had been called.
2362** <S30500>
2363*/
2364void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
2365
2366/*
2367** CAPI3REF: Opening A New Database Connection {H12700} <S40200>
2368**
2369** These routines open an SQLite database file whose name is given by the
2370** filename argument. The filename argument is interpreted as UTF-8 for
2371** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
2372** order for sqlite3_open16(). A [database connection] handle is usually
2373** returned in *ppDb, even if an error occurs. The only exception is that
2374** if SQLite is unable to allocate memory to hold the [sqlite3] object,
2375** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
2376** object. If the database is opened (and/or created) successfully, then
2377** [SQLITE_OK] is returned. Otherwise an [error code] is returned. The
2378** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
2379** an English language description of the error.
2380**
2381** The default encoding for the database will be UTF-8 if
2382** sqlite3_open() or sqlite3_open_v2() is called and
2383** UTF-16 in the native byte order if sqlite3_open16() is used.
2384**
2385** Whether or not an error occurs when it is opened, resources
2386** associated with the [database connection] handle should be released by
2387** passing it to [sqlite3_close()] when it is no longer required.
2388**
2389** The sqlite3_open_v2() interface works like sqlite3_open()
2390** except that it accepts two additional parameters for additional control
2391** over the new database connection. The flags parameter can take one of
2392** the following three values, optionally combined with the
2393** [SQLITE_OPEN_NOMUTEX] flag:
2394**
2395** <dl>
2396** <dt>[SQLITE_OPEN_READONLY]</dt>
2397** <dd>The database is opened in read-only mode. If the database does not
2398** already exist, an error is returned.</dd>
2399**
2400** <dt>[SQLITE_OPEN_READWRITE]</dt>
2401** <dd>The database is opened for reading and writing if possible, or reading
2402** only if the file is write protected by the operating system. In either
2403** case the database must already exist, otherwise an error is returned.</dd>
2404**
2405** <dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
2406** <dd>The database is opened for reading and writing, and is creates it if
2407** it does not already exist. This is the behavior that is always used for
2408** sqlite3_open() and sqlite3_open16().</dd>
2409** </dl>
2410**
2411** If the 3rd parameter to sqlite3_open_v2() is not one of the
2412** combinations shown above or one of the combinations shown above combined
2413** with the [SQLITE_OPEN_NOMUTEX] flag, then the behavior is undefined.
2414**
2415** If the [SQLITE_OPEN_NOMUTEX] flag is set, then mutexes on the
2416** opened [database connection] are disabled and the appliation must
2417** insure that access to the [database connection] and its associated
2418** [prepared statements] is serialized. The [SQLITE_OPEN_NOMUTEX] flag
2419** is the default behavior is SQLite is configured using the
2420** [SQLITE_CONFIG_MULTITHREAD] or [SQLITE_CONFIG_SINGLETHREAD] options
2421** to [sqlite3_config()]. The [SQLITE_OPEN_NOMUTEX] flag only makes a
2422** difference when SQLite is in its default [SQLITE_CONFIG_SERIALIZED] mode.
2423**
2424** If the filename is ":memory:", then a private, temporary in-memory database
2425** is created for the connection. This in-memory database will vanish when
2426** the database connection is closed. Future versions of SQLite might
2427** make use of additional special filenames that begin with the ":" character.
2428** It is recommended that when a database filename actually does begin with
2429** a ":" character you should prefix the filename with a pathname such as
2430** "./" to avoid ambiguity.
2431**
2432** If the filename is an empty string, then a private, temporary
2433** on-disk database will be created. This private database will be
2434** automatically deleted as soon as the database connection is closed.
2435**
2436** The fourth parameter to sqlite3_open_v2() is the name of the
2437** [sqlite3_vfs] object that defines the operating system interface that
2438** the new database connection should use. If the fourth parameter is
2439** a NULL pointer then the default [sqlite3_vfs] object is used.
2440**
2441** <b>Note to Windows users:</b> The encoding used for the filename argument
2442** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
2443** codepage is currently defined. Filenames containing international
2444** characters must be converted to UTF-8 prior to passing them into
2445** sqlite3_open() or sqlite3_open_v2().
2446**
2447** INVARIANTS:
2448**
2449** {H12701} The [sqlite3_open()], [sqlite3_open16()], and
2450** [sqlite3_open_v2()] interfaces create a new
2451** [database connection] associated with
2452** the database file given in their first parameter.
2453**
2454** {H12702} The filename argument is interpreted as UTF-8
2455** for [sqlite3_open()] and [sqlite3_open_v2()] and as UTF-16
2456** in the native byte order for [sqlite3_open16()].
2457**
2458** {H12703} A successful invocation of [sqlite3_open()], [sqlite3_open16()],
2459** or [sqlite3_open_v2()] writes a pointer to a new
2460** [database connection] into *ppDb.
2461**
2462** {H12704} The [sqlite3_open()], [sqlite3_open16()], and
2463** [sqlite3_open_v2()] interfaces return [SQLITE_OK] upon success,
2464** or an appropriate [error code] on failure.
2465**
2466** {H12706} The default text encoding for a new database created using
2467** [sqlite3_open()] or [sqlite3_open_v2()] will be UTF-8.
2468**
2469** {H12707} The default text encoding for a new database created using
2470** [sqlite3_open16()] will be UTF-16.
2471**
2472** {H12709} The [sqlite3_open(F,D)] interface is equivalent to
2473** [sqlite3_open_v2(F,D,G,0)] where the G parameter is
2474** [SQLITE_OPEN_READWRITE]|[SQLITE_OPEN_CREATE].
2475**
2476** {H12711} If the G parameter to [sqlite3_open_v2(F,D,G,V)] contains the
2477** bit value [SQLITE_OPEN_READONLY] then the database is opened
2478** for reading only.
2479**
2480** {H12712} If the G parameter to [sqlite3_open_v2(F,D,G,V)] contains the
2481** bit value [SQLITE_OPEN_READWRITE] then the database is opened
2482** reading and writing if possible, or for reading only if the
2483** file is write protected by the operating system.
2484**
2485** {H12713} If the G parameter to [sqlite3_open_v2(F,D,G,V)] omits the
2486** bit value [SQLITE_OPEN_CREATE] and the database does not
2487** previously exist, an error is returned.
2488**
2489** {H12714} If the G parameter to [sqlite3_open_v2(F,D,G,V)] contains the
2490** bit value [SQLITE_OPEN_CREATE] and the database does not
2491** previously exist, then an attempt is made to create and
2492** initialize the database.
2493**
2494** {H12717} If the filename argument to [sqlite3_open()], [sqlite3_open16()],
2495** or [sqlite3_open_v2()] is ":memory:", then an private,
2496** ephemeral, in-memory database is created for the connection.
2497** <todo>Is SQLITE_OPEN_CREATE|SQLITE_OPEN_READWRITE required
2498** in sqlite3_open_v2()?</todo>
2499**
2500** {H12719} If the filename is NULL or an empty string, then a private,
2501** ephemeral on-disk database will be created.
2502** <todo>Is SQLITE_OPEN_CREATE|SQLITE_OPEN_READWRITE required
2503** in sqlite3_open_v2()?</todo>
2504**
2505** {H12721} The [database connection] created by [sqlite3_open_v2(F,D,G,V)]
2506** will use the [sqlite3_vfs] object identified by the V parameter,
2507** or the default [sqlite3_vfs] object if V is a NULL pointer.
2508**
2509** {H12723} Two [database connections] will share a common cache if both were
2510** opened with the same VFS while [shared cache mode] was enabled and
2511** if both filenames compare equal using memcmp() after having been
2512** processed by the [sqlite3_vfs | xFullPathname] method of the VFS.
2513*/
2514int sqlite3_open(
2515 const char *filename, /* Database filename (UTF-8) */
2516 sqlite3 **ppDb /* OUT: SQLite db handle */
2517);
2518int sqlite3_open16(
2519 const void *filename, /* Database filename (UTF-16) */
2520 sqlite3 **ppDb /* OUT: SQLite db handle */
2521);
2522int sqlite3_open_v2(
2523 const char *filename, /* Database filename (UTF-8) */
2524 sqlite3 **ppDb, /* OUT: SQLite db handle */
2525 int flags, /* Flags */
2526 const char *zVfs /* Name of VFS module to use */
2527);
2528
2529/*
2530** CAPI3REF: Error Codes And Messages {H12800} <S60200>
2531**
2532** The sqlite3_errcode() interface returns the numeric [result code] or
2533** [extended result code] for the most recent failed sqlite3_* API call
2534** associated with a [database connection]. If a prior API call failed
2535** but the most recent API call succeeded, the return value from
2536** sqlite3_errcode() is undefined.
2537**
2538** The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
2539** text that describes the error, as either UTF-8 or UTF-16 respectively.
2540** Memory to hold the error message string is managed internally.
2541** The application does not need to worry about freeing the result.
2542** However, the error string might be overwritten or deallocated by
2543** subsequent calls to other SQLite interface functions.
2544**
2545** If an interface fails with SQLITE_MISUSE, that means the interface
2546** was invoked incorrectly by the application. In that case, the
2547** error code and message may or may not be set.
2548**
2549** INVARIANTS:
2550**
2551** {H12801} The [sqlite3_errcode(D)] interface returns the numeric
2552** [result code] or [extended result code] for the most recently
2553** failed interface call associated with the [database connection] D.
2554**
2555** {H12803} The [sqlite3_errmsg(D)] and [sqlite3_errmsg16(D)]
2556** interfaces return English-language text that describes
2557** the error in the mostly recently failed interface call,
2558** encoded as either UTF-8 or UTF-16 respectively.
2559**
2560** {H12807} The strings returned by [sqlite3_errmsg()] and [sqlite3_errmsg16()]
2561** are valid until the next SQLite interface call.
2562**
2563** {H12808} Calls to API routines that do not return an error code
2564** (example: [sqlite3_data_count()]) do not
2565** change the error code or message returned by
2566** [sqlite3_errcode()], [sqlite3_errmsg()], or [sqlite3_errmsg16()].
2567**
2568** {H12809} Interfaces that are not associated with a specific
2569** [database connection] (examples:
2570** [sqlite3_mprintf()] or [sqlite3_enable_shared_cache()]
2571** do not change the values returned by
2572** [sqlite3_errcode()], [sqlite3_errmsg()], or [sqlite3_errmsg16()].
2573*/
2574int sqlite3_errcode(sqlite3 *db);
2575const char *sqlite3_errmsg(sqlite3*);
2576const void *sqlite3_errmsg16(sqlite3*);
2577
2578/*
2579** CAPI3REF: SQL Statement Object {H13000} <H13010>
2580** KEYWORDS: {prepared statement} {prepared statements}
2581**
2582** An instance of this object represents a single SQL statement.
2583** This object is variously known as a "prepared statement" or a
2584** "compiled SQL statement" or simply as a "statement".
2585**
2586** The life of a statement object goes something like this:
2587**
2588** <ol>
2589** <li> Create the object using [sqlite3_prepare_v2()] or a related
2590** function.
2591** <li> Bind values to [host parameters] using the sqlite3_bind_*()
2592** interfaces.
2593** <li> Run the SQL by calling [sqlite3_step()] one or more times.
2594** <li> Reset the statement using [sqlite3_reset()] then go back
2595** to step 2. Do this zero or more times.
2596** <li> Destroy the object using [sqlite3_finalize()].
2597** </ol>
2598**
2599** Refer to documentation on individual methods above for additional
2600** information.
2601*/
2602typedef struct sqlite3_stmt sqlite3_stmt;
2603
2604/*
2605** CAPI3REF: Run-time Limits {H12760} <S20600>
2606**
2607** This interface allows the size of various constructs to be limited
2608** on a connection by connection basis. The first parameter is the
2609** [database connection] whose limit is to be set or queried. The
2610** second parameter is one of the [limit categories] that define a
2611** class of constructs to be size limited. The third parameter is the
2612** new limit for that construct. The function returns the old limit.
2613**
2614** If the new limit is a negative number, the limit is unchanged.
2615** For the limit category of SQLITE_LIMIT_XYZ there is a hard upper
2616** bound set by a compile-time C preprocessor macro named SQLITE_MAX_XYZ.
2617** (The "_LIMIT_" in the name is changed to "_MAX_".)
2618** Attempts to increase a limit above its hard upper bound are
2619** silently truncated to the hard upper limit.
2620**
2621** Run time limits are intended for use in applications that manage
2622** both their own internal database and also databases that are controlled
2623** by untrusted external sources. An example application might be a
2624** webbrowser that has its own databases for storing history and
2625** separate databases controlled by JavaScript applications downloaded
2626** off the Internet. The internal databases can be given the
2627** large, default limits. Databases managed by external sources can
2628** be given much smaller limits designed to prevent a denial of service
2629** attack. Developers might also want to use the [sqlite3_set_authorizer()]
2630** interface to further control untrusted SQL. The size of the database
2631** created by an untrusted script can be contained using the
2632** [max_page_count] [PRAGMA].
2633**
2634** New run-time limit categories may be added in future releases.
2635**
2636** INVARIANTS:
2637**
2638** {H12762} A successful call to [sqlite3_limit(D,C,V)] where V is
2639** positive changes the limit on the size of construct C in the
2640** [database connection] D to the lesser of V and the hard upper
2641** bound on the size of C that is set at compile-time.
2642**
2643** {H12766} A successful call to [sqlite3_limit(D,C,V)] where V is negative
2644** leaves the state of the [database connection] D unchanged.
2645**
2646** {H12769} A successful call to [sqlite3_limit(D,C,V)] returns the
2647** value of the limit on the size of construct C in the
2648** [database connection] D as it was prior to the call.
2649*/
2650int sqlite3_limit(sqlite3*, int id, int newVal);
2651
2652/*
2653** CAPI3REF: Run-Time Limit Categories {H12790} <H12760>
2654** KEYWORDS: {limit category} {limit categories}
2655**
2656** These constants define various aspects of a [database connection]
2657** that can be limited in size by calls to [sqlite3_limit()].
2658** The meanings of the various limits are as follows:
2659**
2660** <dl>
2661** <dt>SQLITE_LIMIT_LENGTH</dt>
2662** <dd>The maximum size of any string or BLOB or table row.<dd>
2663**
2664** <dt>SQLITE_LIMIT_SQL_LENGTH</dt>
2665** <dd>The maximum length of an SQL statement.</dd>
2666**
2667** <dt>SQLITE_LIMIT_COLUMN</dt>
2668** <dd>The maximum number of columns in a table definition or in the
2669** result set of a SELECT or the maximum number of columns in an index
2670** or in an ORDER BY or GROUP BY clause.</dd>
2671**
2672** <dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
2673** <dd>The maximum depth of the parse tree on any expression.</dd>
2674**
2675** <dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
2676** <dd>The maximum number of terms in a compound SELECT statement.</dd>
2677**
2678** <dt>SQLITE_LIMIT_VDBE_OP</dt>
2679** <dd>The maximum number of instructions in a virtual machine program
2680** used to implement an SQL statement.</dd>
2681**
2682** <dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
2683** <dd>The maximum number of arguments on a function.</dd>
2684**
2685** <dt>SQLITE_LIMIT_ATTACHED</dt>
2686** <dd>The maximum number of attached databases.</dd>
2687**
2688** <dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
2689** <dd>The maximum length of the pattern argument to the LIKE or
2690** GLOB operators.</dd>
2691**
2692** <dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
2693** <dd>The maximum number of variables in an SQL statement that can
2694** be bound.</dd>
2695** </dl>
2696*/
2697#define SQLITE_LIMIT_LENGTH 0
2698#define SQLITE_LIMIT_SQL_LENGTH 1
2699#define SQLITE_LIMIT_COLUMN 2
2700#define SQLITE_LIMIT_EXPR_DEPTH 3
2701#define SQLITE_LIMIT_COMPOUND_SELECT 4
2702#define SQLITE_LIMIT_VDBE_OP 5
2703#define SQLITE_LIMIT_FUNCTION_ARG 6
2704#define SQLITE_LIMIT_ATTACHED 7
2705#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8
2706#define SQLITE_LIMIT_VARIABLE_NUMBER 9
2707
2708/*
2709** CAPI3REF: Compiling An SQL Statement {H13010} <S10000>
2710** KEYWORDS: {SQL statement compiler}
2711**
2712** To execute an SQL query, it must first be compiled into a byte-code
2713** program using one of these routines.
2714**
2715** The first argument, "db", is a [database connection] obtained from a
2716** prior call to [sqlite3_open()], [sqlite3_open_v2()] or [sqlite3_open16()].
2717**
2718** The second argument, "zSql", is the statement to be compiled, encoded
2719** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2()
2720** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2()
2721** use UTF-16.
2722**
2723** If the nByte argument is less than zero, then zSql is read up to the
2724** first zero terminator. If nByte is non-negative, then it is the maximum
2725** number of bytes read from zSql. When nByte is non-negative, the
2726** zSql string ends at either the first '\000' or '\u0000' character or
2727** the nByte-th byte, whichever comes first. If the caller knows
2728** that the supplied string is nul-terminated, then there is a small
2729** performance advantage to be gained by passing an nByte parameter that
2730** is equal to the number of bytes in the input string <i>including</i>
2731** the nul-terminator bytes.
2732**
2733** *pzTail is made to point to the first byte past the end of the
2734** first SQL statement in zSql. These routines only compile the first
2735** statement in zSql, so *pzTail is left pointing to what remains
2736** uncompiled.
2737**
2738** *ppStmt is left pointing to a compiled [prepared statement] that can be
2739** executed using [sqlite3_step()]. If there is an error, *ppStmt is set
2740** to NULL. If the input text contains no SQL (if the input is an empty
2741** string or a comment) then *ppStmt is set to NULL.
2742** {A13018} The calling procedure is responsible for deleting the compiled
2743** SQL statement using [sqlite3_finalize()] after it has finished with it.
2744**
2745** On success, [SQLITE_OK] is returned, otherwise an [error code] is returned.
2746**
2747** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are
2748** recommended for all new programs. The two older interfaces are retained
2749** for backwards compatibility, but their use is discouraged.
2750** In the "v2" interfaces, the prepared statement
2751** that is returned (the [sqlite3_stmt] object) contains a copy of the
2752** original SQL text. This causes the [sqlite3_step()] interface to
2753** behave a differently in two ways:
2754**
2755** <ol>
2756** <li>
2757** If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
2758** always used to do, [sqlite3_step()] will automatically recompile the SQL
2759** statement and try to run it again. If the schema has changed in
2760** a way that makes the statement no longer valid, [sqlite3_step()] will still
2761** return [SQLITE_SCHEMA]. But unlike the legacy behavior, [SQLITE_SCHEMA] is
2762** now a fatal error. Calling [sqlite3_prepare_v2()] again will not make the
2763** error go away. Note: use [sqlite3_errmsg()] to find the text
2764** of the parsing error that results in an [SQLITE_SCHEMA] return.
2765** </li>
2766**
2767** <li>
2768** When an error occurs, [sqlite3_step()] will return one of the detailed
2769** [error codes] or [extended error codes]. The legacy behavior was that
2770** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
2771** and you would have to make a second call to [sqlite3_reset()] in order
2772** to find the underlying cause of the problem. With the "v2" prepare
2773** interfaces, the underlying reason for the error is returned immediately.
2774** </li>
2775** </ol>
2776**
2777** INVARIANTS:
2778**
2779** {H13011} The [sqlite3_prepare(db,zSql,...)] and
2780** [sqlite3_prepare_v2(db,zSql,...)] interfaces interpret the
2781** text in their zSql parameter as UTF-8.
2782**
2783** {H13012} The [sqlite3_prepare16(db,zSql,...)] and
2784** [sqlite3_prepare16_v2(db,zSql,...)] interfaces interpret the
2785** text in their zSql parameter as UTF-16 in the native byte order.
2786**
2787** {H13013} If the nByte argument to [sqlite3_prepare_v2(db,zSql,nByte,...)]
2788** and its variants is less than zero, the SQL text is
2789** read from zSql is read up to the first zero terminator.
2790**
2791** {H13014} If the nByte argument to [sqlite3_prepare_v2(db,zSql,nByte,...)]
2792** and its variants is non-negative, then at most nBytes bytes of
2793** SQL text is read from zSql.
2794**
2795** {H13015} In [sqlite3_prepare_v2(db,zSql,N,P,pzTail)] and its variants
2796** if the zSql input text contains more than one SQL statement
2797** and pzTail is not NULL, then *pzTail is made to point to the
2798** first byte past the end of the first SQL statement in zSql.
2799** <todo>What does *pzTail point to if there is one statement?</todo>
2800**
2801** {H13016} A successful call to [sqlite3_prepare_v2(db,zSql,N,ppStmt,...)]
2802** or one of its variants writes into *ppStmt a pointer to a new
2803** [prepared statement] or a pointer to NULL if zSql contains
2804** nothing other than whitespace or comments.
2805**
2806** {H13019} The [sqlite3_prepare_v2()] interface and its variants return
2807** [SQLITE_OK] or an appropriate [error code] upon failure.
2808**
2809** {H13021} Before [sqlite3_prepare(db,zSql,nByte,ppStmt,pzTail)] or its
2810** variants returns an error (any value other than [SQLITE_OK]),
2811** they first set *ppStmt to NULL.
2812*/
2813int sqlite3_prepare(
2814 sqlite3 *db, /* Database handle */
2815 const char *zSql, /* SQL statement, UTF-8 encoded */
2816 int nByte, /* Maximum length of zSql in bytes. */
2817 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
2818 const char **pzTail /* OUT: Pointer to unused portion of zSql */
2819);
2820int sqlite3_prepare_v2(
2821 sqlite3 *db, /* Database handle */
2822 const char *zSql, /* SQL statement, UTF-8 encoded */
2823 int nByte, /* Maximum length of zSql in bytes. */
2824 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
2825 const char **pzTail /* OUT: Pointer to unused portion of zSql */
2826);
2827int sqlite3_prepare16(
2828 sqlite3 *db, /* Database handle */
2829 const void *zSql, /* SQL statement, UTF-16 encoded */
2830 int nByte, /* Maximum length of zSql in bytes. */
2831 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
2832 const void **pzTail /* OUT: Pointer to unused portion of zSql */
2833);
2834int sqlite3_prepare16_v2(
2835 sqlite3 *db, /* Database handle */
2836 const void *zSql, /* SQL statement, UTF-16 encoded */
2837 int nByte, /* Maximum length of zSql in bytes. */
2838 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
2839 const void **pzTail /* OUT: Pointer to unused portion of zSql */
2840);
2841
2842/*
2843** CAPIREF: Retrieving Statement SQL {H13100} <H13000>
2844**
2845** This interface can be used to retrieve a saved copy of the original
2846** SQL text used to create a [prepared statement] if that statement was
2847** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()].
2848**
2849** INVARIANTS:
2850**
2851** {H13101} If the [prepared statement] passed as the argument to
2852** [sqlite3_sql()] was compiled using either [sqlite3_prepare_v2()] or
2853** [sqlite3_prepare16_v2()], then [sqlite3_sql()] returns
2854** a pointer to a zero-terminated string containing a UTF-8 rendering
2855** of the original SQL statement.
2856**
2857** {H13102} If the [prepared statement] passed as the argument to
2858** [sqlite3_sql()] was compiled using either [sqlite3_prepare()] or
2859** [sqlite3_prepare16()], then [sqlite3_sql()] returns a NULL pointer.
2860**
2861** {H13103} The string returned by [sqlite3_sql(S)] is valid until the
2862** [prepared statement] S is deleted using [sqlite3_finalize(S)].
2863*/
2864const char *sqlite3_sql(sqlite3_stmt *pStmt);
2865
2866/*
2867** CAPI3REF: Dynamically Typed Value Object {H15000} <S20200>
2868** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
2869**
2870** SQLite uses the sqlite3_value object to represent all values
2871** that can be stored in a database table. SQLite uses dynamic typing
2872** for the values it stores. Values stored in sqlite3_value objects
2873** can be integers, floating point values, strings, BLOBs, or NULL.
2874**
2875** An sqlite3_value object may be either "protected" or "unprotected".
2876** Some interfaces require a protected sqlite3_value. Other interfaces
2877** will accept either a protected or an unprotected sqlite3_value.
2878** Every interface that accepts sqlite3_value arguments specifies
2879** whether or not it requires a protected sqlite3_value.
2880**
2881** The terms "protected" and "unprotected" refer to whether or not
2882** a mutex is held. A internal mutex is held for a protected
2883** sqlite3_value object but no mutex is held for an unprotected
2884** sqlite3_value object. If SQLite is compiled to be single-threaded
2885** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
2886** or if SQLite is run in one of reduced mutex modes
2887** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
2888** then there is no distinction between protected and unprotected
2889** sqlite3_value objects and they can be used interchangeably. However,
2890** for maximum code portability it is recommended that applications
2891** still make the distinction between between protected and unprotected
2892** sqlite3_value objects even when not strictly required.
2893**
2894** The sqlite3_value objects that are passed as parameters into the
2895** implementation of [application-defined SQL functions] are protected.
2896** The sqlite3_value object returned by
2897** [sqlite3_column_value()] is unprotected.
2898** Unprotected sqlite3_value objects may only be used with
2899** [sqlite3_result_value()] and [sqlite3_bind_value()].
2900** The [sqlite3_value_blob | sqlite3_value_type()] family of
2901** interfaces require protected sqlite3_value objects.
2902*/
2903typedef struct Mem sqlite3_value;
2904
2905/*
2906** CAPI3REF: SQL Function Context Object {H16001} <S20200>
2907**
2908** The context in which an SQL function executes is stored in an
2909** sqlite3_context object. A pointer to an sqlite3_context object
2910** is always first parameter to [application-defined SQL functions].
2911** The application-defined SQL function implementation will pass this
2912** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
2913** [sqlite3_aggregate_context()], [sqlite3_user_data()],
2914** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
2915** and/or [sqlite3_set_auxdata()].
2916*/
2917typedef struct sqlite3_context sqlite3_context;
2918
2919/*
2920** CAPI3REF: Binding Values To Prepared Statements {H13500} <S70300>
2921** KEYWORDS: {host parameter} {host parameters} {host parameter name}
2922** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
2923**
2924** In the SQL strings input to [sqlite3_prepare_v2()] and its variants,
2925** literals may be replaced by a parameter in one of these forms:
2926**
2927** <ul>
2928** <li> ?
2929** <li> ?NNN
2930** <li> :VVV
2931** <li> @VVV
2932** <li> $VVV
2933** </ul>
2934**
2935** In the parameter forms shown above NNN is an integer literal,
2936** and VVV is an alpha-numeric parameter name. The values of these
2937** parameters (also called "host parameter names" or "SQL parameters")
2938** can be set using the sqlite3_bind_*() routines defined here.
2939**
2940** The first argument to the sqlite3_bind_*() routines is always
2941** a pointer to the [sqlite3_stmt] object returned from
2942** [sqlite3_prepare_v2()] or its variants.
2943**
2944** The second argument is the index of the SQL parameter to be set.
2945** The leftmost SQL parameter has an index of 1. When the same named
2946** SQL parameter is used more than once, second and subsequent
2947** occurrences have the same index as the first occurrence.
2948** The index for named parameters can be looked up using the
2949** [sqlite3_bind_parameter_index()] API if desired. The index
2950** for "?NNN" parameters is the value of NNN.
2951** The NNN value must be between 1 and the [sqlite3_limit()]
2952** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999).
2953**
2954** The third argument is the value to bind to the parameter.
2955**
2956** In those routines that have a fourth argument, its value is the
2957** number of bytes in the parameter. To be clear: the value is the
2958** number of <u>bytes</u> in the value, not the number of characters.
2959** If the fourth parameter is negative, the length of the string is
2960** the number of bytes up to the first zero terminator.
2961**
2962** The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and
2963** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or
2964** string after SQLite has finished with it. If the fifth argument is
2965** the special value [SQLITE_STATIC], then SQLite assumes that the
2966** information is in static, unmanaged space and does not need to be freed.
2967** If the fifth argument has the value [SQLITE_TRANSIENT], then
2968** SQLite makes its own private copy of the data immediately, before
2969** the sqlite3_bind_*() routine returns.
2970**
2971** The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
2972** is filled with zeroes. A zeroblob uses a fixed amount of memory
2973** (just an integer to hold its size) while it is being processed.
2974** Zeroblobs are intended to serve as placeholders for BLOBs whose
2975** content is later written using
2976** [sqlite3_blob_open | incremental BLOB I/O] routines.
2977** A negative value for the zeroblob results in a zero-length BLOB.
2978**
2979** The sqlite3_bind_*() routines must be called after
2980** [sqlite3_prepare_v2()] (and its variants) or [sqlite3_reset()] and
2981** before [sqlite3_step()].
2982** Bindings are not cleared by the [sqlite3_reset()] routine.
2983** Unbound parameters are interpreted as NULL.
2984**
2985** These routines return [SQLITE_OK] on success or an error code if
2986** anything goes wrong. [SQLITE_RANGE] is returned if the parameter
2987** index is out of range. [SQLITE_NOMEM] is returned if malloc() fails.
2988** [SQLITE_MISUSE] might be returned if these routines are called on a
2989** virtual machine that is the wrong state or which has already been finalized.
2990** Detection of misuse is unreliable. Applications should not depend
2991** on SQLITE_MISUSE returns. SQLITE_MISUSE is intended to indicate a
2992** a logic error in the application. Future versions of SQLite might
2993** panic rather than return SQLITE_MISUSE.
2994**
2995** See also: [sqlite3_bind_parameter_count()],
2996** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
2997**
2998** INVARIANTS:
2999**
3000** {H13506} The [SQL statement compiler] recognizes tokens of the forms
3001** "?", "?NNN", "$VVV", ":VVV", and "@VVV" as SQL parameters,
3002** where NNN is any sequence of one or more digits
3003** and where VVV is any sequence of one or more alphanumeric
3004** characters or "::" optionally followed by a string containing
3005** no spaces and contained within parentheses.
3006**
3007** {H13509} The initial value of an SQL parameter is NULL.
3008**
3009** {H13512} The index of an "?" SQL parameter is one larger than the
3010** largest index of SQL parameter to the left, or 1 if
3011** the "?" is the leftmost SQL parameter.
3012**
3013** {H13515} The index of an "?NNN" SQL parameter is the integer NNN.
3014**
3015** {H13518} The index of an ":VVV", "$VVV", or "@VVV" SQL parameter is
3016** the same as the index of leftmost occurrences of the same
3017** parameter, or one more than the largest index over all
3018** parameters to the left if this is the first occurrence
3019** of this parameter, or 1 if this is the leftmost parameter.
3020**
3021** {H13521} The [SQL statement compiler] fails with an [SQLITE_RANGE]
3022** error if the index of an SQL parameter is less than 1
3023** or greater than the compile-time SQLITE_MAX_VARIABLE_NUMBER
3024** parameter.
3025**
3026** {H13524} Calls to [sqlite3_bind_text | sqlite3_bind(S,N,V,...)]
3027** associate the value V with all SQL parameters having an
3028** index of N in the [prepared statement] S.
3029**
3030** {H13527} Calls to [sqlite3_bind_text | sqlite3_bind(S,N,...)]
3031** override prior calls with the same values of S and N.
3032**
3033** {H13530} Bindings established by [sqlite3_bind_text | sqlite3_bind(S,...)]
3034** persist across calls to [sqlite3_reset(S)].
3035**
3036** {H13533} In calls to [sqlite3_bind_blob(S,N,V,L,D)],
3037** [sqlite3_bind_text(S,N,V,L,D)], or
3038** [sqlite3_bind_text16(S,N,V,L,D)] SQLite binds the first L
3039** bytes of the BLOB or string pointed to by V, when L
3040** is non-negative.
3041**
3042** {H13536} In calls to [sqlite3_bind_text(S,N,V,L,D)] or
3043** [sqlite3_bind_text16(S,N,V,L,D)] SQLite binds characters
3044** from V through the first zero character when L is negative.
3045**
3046** {H13539} In calls to [sqlite3_bind_blob(S,N,V,L,D)],
3047** [sqlite3_bind_text(S,N,V,L,D)], or
3048** [sqlite3_bind_text16(S,N,V,L,D)] when D is the special
3049** constant [SQLITE_STATIC], SQLite assumes that the value V
3050** is held in static unmanaged space that will not change
3051** during the lifetime of the binding.
3052**
3053** {H13542} In calls to [sqlite3_bind_blob(S,N,V,L,D)],
3054** [sqlite3_bind_text(S,N,V,L,D)], or
3055** [sqlite3_bind_text16(S,N,V,L,D)] when D is the special
3056** constant [SQLITE_TRANSIENT], the routine makes a
3057** private copy of the value V before it returns.
3058**
3059** {H13545} In calls to [sqlite3_bind_blob(S,N,V,L,D)],
3060** [sqlite3_bind_text(S,N,V,L,D)], or
3061** [sqlite3_bind_text16(S,N,V,L,D)] when D is a pointer to
3062** a function, SQLite invokes that function to destroy the
3063** value V after it has finished using the value V.
3064**
3065** {H13548} In calls to [sqlite3_bind_zeroblob(S,N,V,L)] the value bound
3066** is a BLOB of L bytes, or a zero-length BLOB if L is negative.
3067**
3068** {H13551} In calls to [sqlite3_bind_value(S,N,V)] the V argument may
3069** be either a [protected sqlite3_value] object or an
3070** [unprotected sqlite3_value] object.
3071*/
3072int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
3073int sqlite3_bind_double(sqlite3_stmt*, int, double);
3074int sqlite3_bind_int(sqlite3_stmt*, int, int);
3075int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
3076int sqlite3_bind_null(sqlite3_stmt*, int);
3077int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*));
3078int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
3079int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
3080int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
3081
3082/*
3083** CAPI3REF: Number Of SQL Parameters {H13600} <S70300>
3084**
3085** This routine can be used to find the number of [SQL parameters]
3086** in a [prepared statement]. SQL parameters are tokens of the
3087** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
3088** placeholders for values that are [sqlite3_bind_blob | bound]
3089** to the parameters at a later time.
3090**
3091** This routine actually returns the index of the largest (rightmost)
3092** parameter. For all forms except ?NNN, this will correspond to the
3093** number of unique parameters. If parameters of the ?NNN are used,
3094** there may be gaps in the list.
3095**
3096** See also: [sqlite3_bind_blob|sqlite3_bind()],
3097** [sqlite3_bind_parameter_name()], and
3098** [sqlite3_bind_parameter_index()].
3099**
3100** INVARIANTS:
3101**
3102** {H13601} The [sqlite3_bind_parameter_count(S)] interface returns
3103** the largest index of all SQL parameters in the
3104** [prepared statement] S, or 0 if S contains no SQL parameters.
3105*/
3106int sqlite3_bind_parameter_count(sqlite3_stmt*);
3107
3108/*
3109** CAPI3REF: Name Of A Host Parameter {H13620} <S70300>
3110**
3111** This routine returns a pointer to the name of the n-th
3112** [SQL parameter] in a [prepared statement].
3113** SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
3114** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
3115** respectively.
3116** In other words, the initial ":" or "$" or "@" or "?"
3117** is included as part of the name.
3118** Parameters of the form "?" without a following integer have no name
3119** and are also referred to as "anonymous parameters".
3120**
3121** The first host parameter has an index of 1, not 0.
3122**
3123** If the value n is out of range or if the n-th parameter is
3124** nameless, then NULL is returned. The returned string is
3125** always in UTF-8 encoding even if the named parameter was
3126** originally specified as UTF-16 in [sqlite3_prepare16()] or
3127** [sqlite3_prepare16_v2()].
3128**
3129** See also: [sqlite3_bind_blob|sqlite3_bind()],
3130** [sqlite3_bind_parameter_count()], and
3131** [sqlite3_bind_parameter_index()].
3132**
3133** INVARIANTS:
3134**
3135** {H13621} The [sqlite3_bind_parameter_name(S,N)] interface returns
3136** a UTF-8 rendering of the name of the SQL parameter in
3137** the [prepared statement] S having index N, or
3138** NULL if there is no SQL parameter with index N or if the
3139** parameter with index N is an anonymous parameter "?".
3140*/
3141const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
3142
3143/*
3144** CAPI3REF: Index Of A Parameter With A Given Name {H13640} <S70300>
3145**
3146** Return the index of an SQL parameter given its name. The
3147** index value returned is suitable for use as the second
3148** parameter to [sqlite3_bind_blob|sqlite3_bind()]. A zero
3149** is returned if no matching parameter is found. The parameter
3150** name must be given in UTF-8 even if the original statement
3151** was prepared from UTF-16 text using [sqlite3_prepare16_v2()].
3152**
3153** See also: [sqlite3_bind_blob|sqlite3_bind()],
3154** [sqlite3_bind_parameter_count()], and
3155** [sqlite3_bind_parameter_index()].
3156**
3157** INVARIANTS:
3158**
3159** {H13641} The [sqlite3_bind_parameter_index(S,N)] interface returns
3160** the index of SQL parameter in the [prepared statement]
3161** S whose name matches the UTF-8 string N, or 0 if there is
3162** no match.
3163*/
3164int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
3165
3166/*
3167** CAPI3REF: Reset All Bindings On A Prepared Statement {H13660} <S70300>
3168**
3169** Contrary to the intuition of many, [sqlite3_reset()] does not reset
3170** the [sqlite3_bind_blob | bindings] on a [prepared statement].
3171** Use this routine to reset all host parameters to NULL.
3172**
3173** INVARIANTS:
3174**
3175** {H13661} The [sqlite3_clear_bindings(S)] interface resets all SQL
3176** parameter bindings in the [prepared statement] S back to NULL.
3177*/
3178int sqlite3_clear_bindings(sqlite3_stmt*);
3179
3180/*
3181** CAPI3REF: Number Of Columns In A Result Set {H13710} <S10700>
3182**
3183** Return the number of columns in the result set returned by the
3184** [prepared statement]. This routine returns 0 if pStmt is an SQL
3185** statement that does not return data (for example an [UPDATE]).
3186**
3187** INVARIANTS:
3188**
3189** {H13711} The [sqlite3_column_count(S)] interface returns the number of
3190** columns in the result set generated by the [prepared statement] S,
3191** or 0 if S does not generate a result set.
3192*/
3193int sqlite3_column_count(sqlite3_stmt *pStmt);
3194
3195/*
3196** CAPI3REF: Column Names In A Result Set {H13720} <S10700>
3197**
3198** These routines return the name assigned to a particular column
3199** in the result set of a [SELECT] statement. The sqlite3_column_name()
3200** interface returns a pointer to a zero-terminated UTF-8 string
3201** and sqlite3_column_name16() returns a pointer to a zero-terminated
3202** UTF-16 string. The first parameter is the [prepared statement]
3203** that implements the [SELECT] statement. The second parameter is the
3204** column number. The leftmost column is number 0.
3205**
3206** The returned string pointer is valid until either the [prepared statement]
3207** is destroyed by [sqlite3_finalize()] or until the next call to
3208** sqlite3_column_name() or sqlite3_column_name16() on the same column.
3209**
3210** If sqlite3_malloc() fails during the processing of either routine
3211** (for example during a conversion from UTF-8 to UTF-16) then a
3212** NULL pointer is returned.
3213**
3214** The name of a result column is the value of the "AS" clause for
3215** that column, if there is an AS clause. If there is no AS clause
3216** then the name of the column is unspecified and may change from
3217** one release of SQLite to the next.
3218**
3219** INVARIANTS:
3220**
3221** {H13721} A successful invocation of the [sqlite3_column_name(S,N)]
3222** interface returns the name of the Nth column (where 0 is
3223** the leftmost column) for the result set of the
3224** [prepared statement] S as a zero-terminated UTF-8 string.
3225**
3226** {H13723} A successful invocation of the [sqlite3_column_name16(S,N)]
3227** interface returns the name of the Nth column (where 0 is
3228** the leftmost column) for the result set of the
3229** [prepared statement] S as a zero-terminated UTF-16 string
3230** in the native byte order.
3231**
3232** {H13724} The [sqlite3_column_name()] and [sqlite3_column_name16()]
3233** interfaces return a NULL pointer if they are unable to
3234** allocate memory to hold their normal return strings.
3235**
3236** {H13725} If the N parameter to [sqlite3_column_name(S,N)] or
3237** [sqlite3_column_name16(S,N)] is out of range, then the
3238** interfaces return a NULL pointer.
3239**
3240** {H13726} The strings returned by [sqlite3_column_name(S,N)] and
3241** [sqlite3_column_name16(S,N)] are valid until the next
3242** call to either routine with the same S and N parameters
3243** or until [sqlite3_finalize(S)] is called.
3244**
3245** {H13727} When a result column of a [SELECT] statement contains
3246** an AS clause, the name of that column is the identifier
3247** to the right of the AS keyword.
3248*/
3249const char *sqlite3_column_name(sqlite3_stmt*, int N);
3250const void *sqlite3_column_name16(sqlite3_stmt*, int N);
3251
3252/*
3253** CAPI3REF: Source Of Data In A Query Result {H13740} <S10700>
3254**
3255** These routines provide a means to determine what column of what
3256** table in which database a result of a [SELECT] statement comes from.
3257** The name of the database or table or column can be returned as
3258** either a UTF-8 or UTF-16 string. The _database_ routines return
3259** the database name, the _table_ routines return the table name, and
3260** the origin_ routines return the column name.
3261** The returned string is valid until the [prepared statement] is destroyed
3262** using [sqlite3_finalize()] or until the same information is requested
3263** again in a different encoding.
3264**
3265** The names returned are the original un-aliased names of the
3266** database, table, and column.
3267**
3268** The first argument to the following calls is a [prepared statement].
3269** These functions return information about the Nth column returned by
3270** the statement, where N is the second function argument.
3271**
3272** If the Nth column returned by the statement is an expression or
3273** subquery and is not a column value, then all of these functions return
3274** NULL. These routine might also return NULL if a memory allocation error
3275** occurs. Otherwise, they return the name of the attached database, table
3276** and column that query result column was extracted from.
3277**
3278** As with all other SQLite APIs, those postfixed with "16" return
3279** UTF-16 encoded strings, the other functions return UTF-8. {END}
3280**
3281** These APIs are only available if the library was compiled with the
3282** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined.
3283**
3284** {A13751}
3285** If two or more threads call one or more of these routines against the same
3286** prepared statement and column at the same time then the results are
3287** undefined.
3288**
3289** INVARIANTS:
3290**
3291** {H13741} The [sqlite3_column_database_name(S,N)] interface returns either
3292** the UTF-8 zero-terminated name of the database from which the
3293** Nth result column of the [prepared statement] S is extracted,
3294** or NULL if the Nth column of S is a general expression
3295** or if unable to allocate memory to store the name.
3296**
3297** {H13742} The [sqlite3_column_database_name16(S,N)] interface returns either
3298** the UTF-16 native byte order zero-terminated name of the database
3299** from which the Nth result column of the [prepared statement] S is
3300** extracted, or NULL if the Nth column of S is a general expression
3301** or if unable to allocate memory to store the name.
3302**
3303** {H13743} The [sqlite3_column_table_name(S,N)] interface returns either
3304** the UTF-8 zero-terminated name of the table from which the
3305** Nth result column of the [prepared statement] S is extracted,
3306** or NULL if the Nth column of S is a general expression
3307** or if unable to allocate memory to store the name.
3308**
3309** {H13744} The [sqlite3_column_table_name16(S,N)] interface returns either
3310** the UTF-16 native byte order zero-terminated name of the table
3311** from which the Nth result column of the [prepared statement] S is
3312** extracted, or NULL if the Nth column of S is a general expression
3313** or if unable to allocate memory to store the name.
3314**
3315** {H13745} The [sqlite3_column_origin_name(S,N)] interface returns either
3316** the UTF-8 zero-terminated name of the table column from which the
3317** Nth result column of the [prepared statement] S is extracted,
3318** or NULL if the Nth column of S is a general expression
3319** or if unable to allocate memory to store the name.
3320**
3321** {H13746} The [sqlite3_column_origin_name16(S,N)] interface returns either
3322** the UTF-16 native byte order zero-terminated name of the table
3323** column from which the Nth result column of the
3324** [prepared statement] S is extracted, or NULL if the Nth column
3325** of S is a general expression or if unable to allocate memory
3326** to store the name.
3327**
3328** {H13748} The return values from
3329** [sqlite3_column_database_name | column metadata interfaces]
3330** are valid for the lifetime of the [prepared statement]
3331** or until the encoding is changed by another metadata
3332** interface call for the same prepared statement and column.
3333**
3334** ASSUMPTIONS:
3335**
3336** {A13751} If two or more threads call one or more
3337** [sqlite3_column_database_name | column metadata interfaces]
3338** for the same [prepared statement] and result column
3339** at the same time then the results are undefined.
3340*/
3341const char *sqlite3_column_database_name(sqlite3_stmt*,int);
3342const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
3343const char *sqlite3_column_table_name(sqlite3_stmt*,int);
3344const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
3345const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
3346const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
3347
3348/*
3349** CAPI3REF: Declared Datatype Of A Query Result {H13760} <S10700>
3350**
3351** The first parameter is a [prepared statement].
3352** If this statement is a [SELECT] statement and the Nth column of the
3353** returned result set of that [SELECT] is a table column (not an
3354** expression or subquery) then the declared type of the table
3355** column is returned. If the Nth column of the result set is an
3356** expression or subquery, then a NULL pointer is returned.
3357** The returned string is always UTF-8 encoded. {END}
3358**
3359** For example, given the database schema:
3360**
3361** CREATE TABLE t1(c1 VARIANT);
3362**
3363** and the following statement to be compiled:
3364**
3365** SELECT c1 + 1, c1 FROM t1;
3366**
3367** this routine would return the string "VARIANT" for the second result
3368** column (i==1), and a NULL pointer for the first result column (i==0).
3369**
3370** SQLite uses dynamic run-time typing. So just because a column
3371** is declared to contain a particular type does not mean that the
3372** data stored in that column is of the declared type. SQLite is
3373** strongly typed, but the typing is dynamic not static. Type
3374** is associated with individual values, not with the containers
3375** used to hold those values.
3376**
3377** INVARIANTS:
3378**
3379** {H13761} A successful call to [sqlite3_column_decltype(S,N)] returns a
3380** zero-terminated UTF-8 string containing the declared datatype
3381** of the table column that appears as the Nth column (numbered
3382** from 0) of the result set to the [prepared statement] S.
3383**
3384** {H13762} A successful call to [sqlite3_column_decltype16(S,N)]
3385** returns a zero-terminated UTF-16 native byte order string
3386** containing the declared datatype of the table column that appears
3387** as the Nth column (numbered from 0) of the result set to the
3388** [prepared statement] S.
3389**
3390** {H13763} If N is less than 0 or N is greater than or equal to
3391** the number of columns in the [prepared statement] S,
3392** or if the Nth column of S is an expression or subquery rather
3393** than a table column, or if a memory allocation failure
3394** occurs during encoding conversions, then
3395** calls to [sqlite3_column_decltype(S,N)] or
3396** [sqlite3_column_decltype16(S,N)] return NULL.
3397*/
3398const char *sqlite3_column_decltype(sqlite3_stmt*,int);
3399const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
3400
3401/*
3402** CAPI3REF: Evaluate An SQL Statement {H13200} <S10000>
3403**
3404** After a [prepared statement] has been prepared using either
3405** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy
3406** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
3407** must be called one or more times to evaluate the statement.
3408**
3409** The details of the behavior of the sqlite3_step() interface depend
3410** on whether the statement was prepared using the newer "v2" interface
3411** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy
3412** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the
3413** new "v2" interface is recommended for new applications but the legacy
3414** interface will continue to be supported.
3415**
3416** In the legacy interface, the return value will be either [SQLITE_BUSY],
3417** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
3418** With the "v2" interface, any of the other [result codes] or
3419** [extended result codes] might be returned as well.
3420**
3421** [SQLITE_BUSY] means that the database engine was unable to acquire the
3422** database locks it needs to do its job. If the statement is a [COMMIT]
3423** or occurs outside of an explicit transaction, then you can retry the
3424** statement. If the statement is not a [COMMIT] and occurs within a
3425** explicit transaction then you should rollback the transaction before
3426** continuing.
3427**
3428** [SQLITE_DONE] means that the statement has finished executing
3429** successfully. sqlite3_step() should not be called again on this virtual
3430** machine without first calling [sqlite3_reset()] to reset the virtual
3431** machine back to its initial state.
3432**
3433** If the SQL statement being executed returns any data, then [SQLITE_ROW]
3434** is returned each time a new row of data is ready for processing by the
3435** caller. The values may be accessed using the [column access functions].
3436** sqlite3_step() is called again to retrieve the next row of data.
3437**
3438** [SQLITE_ERROR] means that a run-time error (such as a constraint
3439** violation) has occurred. sqlite3_step() should not be called again on
3440** the VM. More information may be found by calling [sqlite3_errmsg()].
3441** With the legacy interface, a more specific error code (for example,
3442** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
3443** can be obtained by calling [sqlite3_reset()] on the
3444** [prepared statement]. In the "v2" interface,
3445** the more specific error code is returned directly by sqlite3_step().
3446**
3447** [SQLITE_MISUSE] means that the this routine was called inappropriately.
3448** Perhaps it was called on a [prepared statement] that has
3449** already been [sqlite3_finalize | finalized] or on one that had
3450** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could
3451** be the case that the same database connection is being used by two or
3452** more threads at the same moment in time.
3453**
3454** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
3455** API always returns a generic error code, [SQLITE_ERROR], following any
3456** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call
3457** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
3458** specific [error codes] that better describes the error.
3459** We admit that this is a goofy design. The problem has been fixed
3460** with the "v2" interface. If you prepare all of your SQL statements
3461** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead
3462** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
3463** then the more specific [error codes] are returned directly
3464** by sqlite3_step(). The use of the "v2" interface is recommended.
3465**
3466** INVARIANTS:
3467**
3468** {H13202} If the [prepared statement] S is ready to be run, then
3469** [sqlite3_step(S)] advances that prepared statement until
3470** completion or until it is ready to return another row of the
3471** result set, or until an [sqlite3_interrupt | interrupt]
3472** or a run-time error occurs.
3473**
3474** {H15304} When a call to [sqlite3_step(S)] causes the [prepared statement]
3475** S to run to completion, the function returns [SQLITE_DONE].
3476**
3477** {H15306} When a call to [sqlite3_step(S)] stops because it is ready to
3478** return another row of the result set, it returns [SQLITE_ROW].
3479**
3480** {H15308} If a call to [sqlite3_step(S)] encounters an
3481** [sqlite3_interrupt | interrupt] or a run-time error,
3482** it returns an appropriate error code that is not one of
3483** [SQLITE_OK], [SQLITE_ROW], or [SQLITE_DONE].
3484**
3485** {H15310} If an [sqlite3_interrupt | interrupt] or a run-time error
3486** occurs during a call to [sqlite3_step(S)]
3487** for a [prepared statement] S created using
3488** legacy interfaces [sqlite3_prepare()] or
3489** [sqlite3_prepare16()], then the function returns either
3490** [SQLITE_ERROR], [SQLITE_BUSY], or [SQLITE_MISUSE].
3491*/
3492int sqlite3_step(sqlite3_stmt*);
3493
3494/*
3495** CAPI3REF: Number of columns in a result set {H13770} <S10700>
3496**
3497** Returns the number of values in the current row of the result set.
3498**
3499** INVARIANTS:
3500**
3501** {H13771} After a call to [sqlite3_step(S)] that returns [SQLITE_ROW],
3502** the [sqlite3_data_count(S)] routine will return the same value
3503** as the [sqlite3_column_count(S)] function.
3504**
3505** {H13772} After [sqlite3_step(S)] has returned any value other than
3506** [SQLITE_ROW] or before [sqlite3_step(S)] has been called on the
3507** [prepared statement] for the first time since it was
3508** [sqlite3_prepare | prepared] or [sqlite3_reset | reset],
3509** the [sqlite3_data_count(S)] routine returns zero.
3510*/
3511int sqlite3_data_count(sqlite3_stmt *pStmt);
3512
3513/*
3514** CAPI3REF: Fundamental Datatypes {H10265} <S10110><S10120>
3515** KEYWORDS: SQLITE_TEXT
3516**
3517** {H10266} Every value in SQLite has one of five fundamental datatypes:
3518**
3519** <ul>
3520** <li> 64-bit signed integer
3521** <li> 64-bit IEEE floating point number
3522** <li> string
3523** <li> BLOB
3524** <li> NULL
3525** </ul> {END}
3526**
3527** These constants are codes for each of those types.
3528**
3529** Note that the SQLITE_TEXT constant was also used in SQLite version 2
3530** for a completely different meaning. Software that links against both
3531** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
3532** SQLITE_TEXT.
3533*/
3534#define SQLITE_INTEGER 1
3535#define SQLITE_FLOAT 2
3536#define SQLITE_BLOB 4
3537#define SQLITE_NULL 5
3538#ifdef SQLITE_TEXT
3539# undef SQLITE_TEXT
3540#else
3541# define SQLITE_TEXT 3
3542#endif
3543#define SQLITE3_TEXT 3
3544
3545/*
3546** CAPI3REF: Result Values From A Query {H13800} <S10700>
3547** KEYWORDS: {column access functions}
3548**
3549** These routines form the "result set query" interface.
3550**
3551** These routines return information about a single column of the current
3552** result row of a query. In every case the first argument is a pointer
3553** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
3554** that was returned from [sqlite3_prepare_v2()] or one of its variants)
3555** and the second argument is the index of the column for which information
3556** should be returned. The leftmost column of the result set has the index 0.
3557**
3558** If the SQL statement does not currently point to a valid row, or if the
3559** column index is out of range, the result is undefined.
3560** These routines may only be called when the most recent call to
3561** [sqlite3_step()] has returned [SQLITE_ROW] and neither
3562** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
3563** If any of these routines are called after [sqlite3_reset()] or
3564** [sqlite3_finalize()] or after [sqlite3_step()] has returned
3565** something other than [SQLITE_ROW], the results are undefined.
3566** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
3567** are called from a different thread while any of these routines
3568** are pending, then the results are undefined.
3569**
3570** The sqlite3_column_type() routine returns the
3571** [SQLITE_INTEGER | datatype code] for the initial data type
3572** of the result column. The returned value is one of [SQLITE_INTEGER],
3573** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value
3574** returned by sqlite3_column_type() is only meaningful if no type
3575** conversions have occurred as described below. After a type conversion,
3576** the value returned by sqlite3_column_type() is undefined. Future
3577** versions of SQLite may change the behavior of sqlite3_column_type()
3578** following a type conversion.
3579**
3580** If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
3581** routine returns the number of bytes in that BLOB or string.
3582** If the result is a UTF-16 string, then sqlite3_column_bytes() converts
3583** the string to UTF-8 and then returns the number of bytes.
3584** If the result is a numeric value then sqlite3_column_bytes() uses
3585** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
3586** the number of bytes in that string.
3587** The value returned does not include the zero terminator at the end
3588** of the string. For clarity: the value returned is the number of
3589** bytes in the string, not the number of characters.
3590**
3591** Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
3592** even empty strings, are always zero terminated. The return
3593** value from sqlite3_column_blob() for a zero-length BLOB is an arbitrary
3594** pointer, possibly even a NULL pointer.
3595**
3596** The sqlite3_column_bytes16() routine is similar to sqlite3_column_bytes()
3597** but leaves the result in UTF-16 in native byte order instead of UTF-8.
3598** The zero terminator is not included in this count.
3599**
3600** The object returned by [sqlite3_column_value()] is an
3601** [unprotected sqlite3_value] object. An unprotected sqlite3_value object
3602** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()].
3603** If the [unprotected sqlite3_value] object returned by
3604** [sqlite3_column_value()] is used in any other way, including calls
3605** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
3606** or [sqlite3_value_bytes()], then the behavior is undefined.
3607**
3608** These routines attempt to convert the value where appropriate. For
3609** example, if the internal representation is FLOAT and a text result
3610** is requested, [sqlite3_snprintf()] is used internally to perform the
3611** conversion automatically. The following table details the conversions
3612** that are applied:
3613**
3614** <blockquote>
3615** <table border="1">
3616** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion
3617**
3618** <tr><td> NULL <td> INTEGER <td> Result is 0
3619** <tr><td> NULL <td> FLOAT <td> Result is 0.0
3620** <tr><td> NULL <td> TEXT <td> Result is NULL pointer
3621** <tr><td> NULL <td> BLOB <td> Result is NULL pointer
3622** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float
3623** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer
3624** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT
3625** <tr><td> FLOAT <td> INTEGER <td> Convert from float to integer
3626** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float
3627** <tr><td> FLOAT <td> BLOB <td> Same as FLOAT->TEXT
3628** <tr><td> TEXT <td> INTEGER <td> Use atoi()
3629** <tr><td> TEXT <td> FLOAT <td> Use atof()
3630** <tr><td> TEXT <td> BLOB <td> No change
3631** <tr><td> BLOB <td> INTEGER <td> Convert to TEXT then use atoi()
3632** <tr><td> BLOB <td> FLOAT <td> Convert to TEXT then use atof()
3633** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed
3634** </table>
3635** </blockquote>
3636**
3637** The table above makes reference to standard C library functions atoi()
3638** and atof(). SQLite does not really use these functions. It has its
3639** own equivalent internal routines. The atoi() and atof() names are
3640** used in the table for brevity and because they are familiar to most
3641** C programmers.
3642**
3643** Note that when type conversions occur, pointers returned by prior
3644** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
3645** sqlite3_column_text16() may be invalidated.
3646** Type conversions and pointer invalidations might occur
3647** in the following cases:
3648**
3649** <ul>
3650** <li> The initial content is a BLOB and sqlite3_column_text() or
3651** sqlite3_column_text16() is called. A zero-terminator might
3652** need to be added to the string.</li>
3653** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
3654** sqlite3_column_text16() is called. The content must be converted
3655** to UTF-16.</li>
3656** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
3657** sqlite3_column_text() is called. The content must be converted
3658** to UTF-8.</li>
3659** </ul>
3660**
3661** Conversions between UTF-16be and UTF-16le are always done in place and do
3662** not invalidate a prior pointer, though of course the content of the buffer
3663** that the prior pointer points to will have been modified. Other kinds
3664** of conversion are done in place when it is possible, but sometimes they
3665** are not possible and in those cases prior pointers are invalidated.
3666**
3667** The safest and easiest to remember policy is to invoke these routines
3668** in one of the following ways:
3669**
3670** <ul>
3671** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
3672** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
3673** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
3674** </ul>
3675**
3676** In other words, you should call sqlite3_column_text(),
3677** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
3678** into the desired format, then invoke sqlite3_column_bytes() or
3679** sqlite3_column_bytes16() to find the size of the result. Do not mix calls
3680** to sqlite3_column_text() or sqlite3_column_blob() with calls to
3681** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
3682** with calls to sqlite3_column_bytes().
3683**
3684** The pointers returned are valid until a type conversion occurs as
3685** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
3686** [sqlite3_finalize()] is called. The memory space used to hold strings
3687** and BLOBs is freed automatically. Do <b>not</b> pass the pointers returned
3688** [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
3689** [sqlite3_free()].
3690**
3691** If a memory allocation error occurs during the evaluation of any
3692** of these routines, a default value is returned. The default value
3693** is either the integer 0, the floating point number 0.0, or a NULL
3694** pointer. Subsequent calls to [sqlite3_errcode()] will return
3695** [SQLITE_NOMEM].
3696**
3697** INVARIANTS:
3698**
3699** {H13803} The [sqlite3_column_blob(S,N)] interface converts the
3700** Nth column in the current row of the result set for
3701** the [prepared statement] S into a BLOB and then returns a
3702** pointer to the converted value.
3703**
3704** {H13806} The [sqlite3_column_bytes(S,N)] interface returns the
3705** number of bytes in the BLOB or string (exclusive of the
3706** zero terminator on the string) that was returned by the
3707** most recent call to [sqlite3_column_blob(S,N)] or
3708** [sqlite3_column_text(S,N)].
3709**
3710** {H13809} The [sqlite3_column_bytes16(S,N)] interface returns the
3711** number of bytes in the string (exclusive of the
3712** zero terminator on the string) that was returned by the
3713** most recent call to [sqlite3_column_text16(S,N)].
3714**
3715** {H13812} The [sqlite3_column_double(S,N)] interface converts the
3716** Nth column in the current row of the result set for the
3717** [prepared statement] S into a floating point value and
3718** returns a copy of that value.
3719**
3720** {H13815} The [sqlite3_column_int(S,N)] interface converts the
3721** Nth column in the current row of the result set for the
3722** [prepared statement] S into a 64-bit signed integer and
3723** returns the lower 32 bits of that integer.
3724**
3725** {H13818} The [sqlite3_column_int64(S,N)] interface converts the
3726** Nth column in the current row of the result set for the
3727** [prepared statement] S into a 64-bit signed integer and
3728** returns a copy of that integer.
3729**
3730** {H13821} The [sqlite3_column_text(S,N)] interface converts the
3731** Nth column in the current row of the result set for
3732** the [prepared statement] S into a zero-terminated UTF-8
3733** string and returns a pointer to that string.
3734**
3735** {H13824} The [sqlite3_column_text16(S,N)] interface converts the
3736** Nth column in the current row of the result set for the
3737** [prepared statement] S into a zero-terminated 2-byte
3738** aligned UTF-16 native byte order string and returns
3739** a pointer to that string.
3740**
3741** {H13827} The [sqlite3_column_type(S,N)] interface returns
3742** one of [SQLITE_NULL], [SQLITE_INTEGER], [SQLITE_FLOAT],
3743** [SQLITE_TEXT], or [SQLITE_BLOB] as appropriate for
3744** the Nth column in the current row of the result set for
3745** the [prepared statement] S.
3746**
3747** {H13830} The [sqlite3_column_value(S,N)] interface returns a
3748** pointer to an [unprotected sqlite3_value] object for the
3749** Nth column in the current row of the result set for
3750** the [prepared statement] S.
3751*/
3752const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
3753int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
3754int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
3755double sqlite3_column_double(sqlite3_stmt*, int iCol);
3756int sqlite3_column_int(sqlite3_stmt*, int iCol);
3757sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
3758const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
3759const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
3760int sqlite3_column_type(sqlite3_stmt*, int iCol);
3761sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
3762
3763/*
3764** CAPI3REF: Destroy A Prepared Statement Object {H13300} <S70300><S30100>
3765**
3766** The sqlite3_finalize() function is called to delete a [prepared statement].
3767** If the statement was executed successfully or not executed at all, then
3768** SQLITE_OK is returned. If execution of the statement failed then an
3769** [error code] or [extended error code] is returned.
3770**
3771** This routine can be called at any point during the execution of the
3772** [prepared statement]. If the virtual machine has not
3773** completed execution when this routine is called, that is like
3774** encountering an error or an [sqlite3_interrupt | interrupt].
3775** Incomplete updates may be rolled back and transactions canceled,
3776** depending on the circumstances, and the
3777** [error code] returned will be [SQLITE_ABORT].
3778**
3779** INVARIANTS:
3780**
3781** {H11302} The [sqlite3_finalize(S)] interface destroys the
3782** [prepared statement] S and releases all
3783** memory and file resources held by that object.
3784**
3785** {H11304} If the most recent call to [sqlite3_step(S)] for the
3786** [prepared statement] S returned an error,
3787** then [sqlite3_finalize(S)] returns that same error.
3788*/
3789int sqlite3_finalize(sqlite3_stmt *pStmt);
3790
3791/*
3792** CAPI3REF: Reset A Prepared Statement Object {H13330} <S70300>
3793**
3794** The sqlite3_reset() function is called to reset a [prepared statement]
3795** object back to its initial state, ready to be re-executed.
3796** Any SQL statement variables that had values bound to them using
3797** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
3798** Use [sqlite3_clear_bindings()] to reset the bindings.
3799**
3800** {H11332} The [sqlite3_reset(S)] interface resets the [prepared statement] S
3801** back to the beginning of its program.
3802**
3803** {H11334} If the most recent call to [sqlite3_step(S)] for the
3804** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE],
3805** or if [sqlite3_step(S)] has never before been called on S,
3806** then [sqlite3_reset(S)] returns [SQLITE_OK].
3807**
3808** {H11336} If the most recent call to [sqlite3_step(S)] for the
3809** [prepared statement] S indicated an error, then
3810** [sqlite3_reset(S)] returns an appropriate [error code].
3811**
3812** {H11338} The [sqlite3_reset(S)] interface does not change the values
3813** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
3814*/
3815int sqlite3_reset(sqlite3_stmt *pStmt);
3816
3817/*
3818** CAPI3REF: Create Or Redefine SQL Functions {H16100} <S20200>
3819** KEYWORDS: {function creation routines}
3820** KEYWORDS: {application-defined SQL function}
3821** KEYWORDS: {application-defined SQL functions}
3822**
3823** These two functions (collectively known as "function creation routines")
3824** are used to add SQL functions or aggregates or to redefine the behavior
3825** of existing SQL functions or aggregates. The only difference between the
3826** two is that the second parameter, the name of the (scalar) function or
3827** aggregate, is encoded in UTF-8 for sqlite3_create_function() and UTF-16
3828** for sqlite3_create_function16().
3829**
3830** The first parameter is the [database connection] to which the SQL
3831** function is to be added. If a single program uses more than one database
3832** connection internally, then SQL functions must be added individually to
3833** each database connection.
3834**
3835** The second parameter is the name of the SQL function to be created or
3836** redefined. The length of the name is limited to 255 bytes, exclusive of
3837** the zero-terminator. Note that the name length limit is in bytes, not
3838** characters. Any attempt to create a function with a longer name
3839** will result in [SQLITE_ERROR] being returned.
3840**
3841** The third parameter is the number of arguments that the SQL function or
3842** aggregate takes. If this parameter is negative, then the SQL function or
3843** aggregate may take any number of arguments.
3844**
3845** The fourth parameter, eTextRep, specifies what
3846** [SQLITE_UTF8 | text encoding] this SQL function prefers for
3847** its parameters. Any SQL function implementation should be able to work
3848** work with UTF-8, UTF-16le, or UTF-16be. But some implementations may be
3849** more efficient with one encoding than another. It is allowed to
3850** invoke sqlite3_create_function() or sqlite3_create_function16() multiple
3851** times with the same function but with different values of eTextRep.
3852** When multiple implementations of the same function are available, SQLite
3853** will pick the one that involves the least amount of data conversion.
3854** If there is only a single implementation which does not care what text
3855** encoding is used, then the fourth argument should be [SQLITE_ANY].
3856**
3857** The fifth parameter is an arbitrary pointer. The implementation of the
3858** function can gain access to this pointer using [sqlite3_user_data()].
3859**
3860** The seventh, eighth and ninth parameters, xFunc, xStep and xFinal, are
3861** pointers to C-language functions that implement the SQL function or
3862** aggregate. A scalar SQL function requires an implementation of the xFunc
3863** callback only, NULL pointers should be passed as the xStep and xFinal
3864** parameters. An aggregate SQL function requires an implementation of xStep
3865** and xFinal and NULL should be passed for xFunc. To delete an existing
3866** SQL function or aggregate, pass NULL for all three function callbacks.
3867**
3868** It is permitted to register multiple implementations of the same
3869** functions with the same name but with either differing numbers of
3870** arguments or differing preferred text encodings. SQLite will use
3871** the implementation most closely matches the way in which the
3872** SQL function is used.
3873**
3874** INVARIANTS:
3875**
3876** {H16103} The [sqlite3_create_function16()] interface behaves exactly
3877** like [sqlite3_create_function()] in every way except that it
3878** interprets the zFunctionName argument as zero-terminated UTF-16
3879** native byte order instead of as zero-terminated UTF-8.
3880**
3881** {H16106} A successful invocation of
3882** the [sqlite3_create_function(D,X,N,E,...)] interface registers
3883** or replaces callback functions in the [database connection] D
3884** used to implement the SQL function named X with N parameters
3885** and having a preferred text encoding of E.
3886**
3887** {H16109} A successful call to [sqlite3_create_function(D,X,N,E,P,F,S,L)]
3888** replaces the P, F, S, and L values from any prior calls with
3889** the same D, X, N, and E values.
3890**
3891** {H16112} The [sqlite3_create_function(D,X,...)] interface fails with
3892** a return code of [SQLITE_ERROR] if the SQL function name X is
3893** longer than 255 bytes exclusive of the zero terminator.
3894**
3895** {H16118} Either F must be NULL and S and L are non-NULL or else F
3896** is non-NULL and S and L are NULL, otherwise
3897** [sqlite3_create_function(D,X,N,E,P,F,S,L)] returns [SQLITE_ERROR].
3898**
3899** {H16121} The [sqlite3_create_function(D,...)] interface fails with an
3900** error code of [SQLITE_BUSY] if there exist [prepared statements]
3901** associated with the [database connection] D.
3902**
3903** {H16124} The [sqlite3_create_function(D,X,N,...)] interface fails with an
3904** error code of [SQLITE_ERROR] if parameter N (specifying the number
3905** of arguments to the SQL function being registered) is less
3906** than -1 or greater than 127.
3907**
3908** {H16127} When N is non-negative, the [sqlite3_create_function(D,X,N,...)]
3909** interface causes callbacks to be invoked for the SQL function
3910** named X when the number of arguments to the SQL function is
3911** exactly N.
3912**
3913** {H16130} When N is -1, the [sqlite3_create_function(D,X,N,...)]
3914** interface causes callbacks to be invoked for the SQL function
3915** named X with any number of arguments.
3916**
3917** {H16133} When calls to [sqlite3_create_function(D,X,N,...)]
3918** specify multiple implementations of the same function X
3919** and when one implementation has N>=0 and the other has N=(-1)
3920** the implementation with a non-zero N is preferred.
3921**
3922** {H16136} When calls to [sqlite3_create_function(D,X,N,E,...)]
3923** specify multiple implementations of the same function X with
3924** the same number of arguments N but with different
3925** encodings E, then the implementation where E matches the
3926** database encoding is preferred.
3927**
3928** {H16139} For an aggregate SQL function created using
3929** [sqlite3_create_function(D,X,N,E,P,0,S,L)] the finalizer
3930** function L will always be invoked exactly once if the
3931** step function S is called one or more times.
3932**
3933** {H16142} When SQLite invokes either the xFunc or xStep function of
3934** an application-defined SQL function or aggregate created
3935** by [sqlite3_create_function()] or [sqlite3_create_function16()],
3936** then the array of [sqlite3_value] objects passed as the
3937** third parameter are always [protected sqlite3_value] objects.
3938*/
3939int sqlite3_create_function(
3940 sqlite3 *db,
3941 const char *zFunctionName,
3942 int nArg,
3943 int eTextRep,
3944 void *pApp,
3945 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
3946 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
3947 void (*xFinal)(sqlite3_context*)
3948);
3949int sqlite3_create_function16(
3950 sqlite3 *db,
3951 const void *zFunctionName,
3952 int nArg,
3953 int eTextRep,
3954 void *pApp,
3955 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
3956 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
3957 void (*xFinal)(sqlite3_context*)
3958);
3959
3960/*
3961** CAPI3REF: Text Encodings {H10267} <S50200> <H16100>
3962**
3963** These constant define integer codes that represent the various
3964** text encodings supported by SQLite.
3965*/
3966#define SQLITE_UTF8 1
3967#define SQLITE_UTF16LE 2
3968#define SQLITE_UTF16BE 3
3969#define SQLITE_UTF16 4 /* Use native byte order */
3970#define SQLITE_ANY 5 /* sqlite3_create_function only */
3971#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */
3972
3973/*
3974** CAPI3REF: Deprecated Functions
3975** DEPRECATED
3976**
3977** These functions are [deprecated]. In order to maintain
3978** backwards compatibility with older code, these functions continue
3979** to be supported. However, new applications should avoid
3980** the use of these functions. To help encourage people to avoid
3981** using these functions, we are not going to tell you want they do.
3982*/
3983SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*);
3984SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);
3985SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
3986SQLITE_DEPRECATED int sqlite3_global_recover(void);
3987SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);
3988SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),void*,sqlite3_int64);
3989
3990/*
3991** CAPI3REF: Obtaining SQL Function Parameter Values {H15100} <S20200>
3992**
3993** The C-language implementation of SQL functions and aggregates uses
3994** this set of interface routines to access the parameter values on
3995** the function or aggregate.
3996**
3997** The xFunc (for scalar functions) or xStep (for aggregates) parameters
3998** to [sqlite3_create_function()] and [sqlite3_create_function16()]
3999** define callbacks that implement the SQL functions and aggregates.
4000** The 4th parameter to these callbacks is an array of pointers to
4001** [protected sqlite3_value] objects. There is one [sqlite3_value] object for
4002** each parameter to the SQL function. These routines are used to
4003** extract values from the [sqlite3_value] objects.
4004**
4005** These routines work only with [protected sqlite3_value] objects.
4006** Any attempt to use these routines on an [unprotected sqlite3_value]
4007** object results in undefined behavior.
4008**
4009** These routines work just like the corresponding [column access functions]
4010** except that these routines take a single [protected sqlite3_value] object
4011** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
4012**
4013** The sqlite3_value_text16() interface extracts a UTF-16 string
4014** in the native byte-order of the host machine. The
4015** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
4016** extract UTF-16 strings as big-endian and little-endian respectively.
4017**
4018** The sqlite3_value_numeric_type() interface attempts to apply
4019** numeric affinity to the value. This means that an attempt is
4020** made to convert the value to an integer or floating point. If
4021** such a conversion is possible without loss of information (in other
4022** words, if the value is a string that looks like a number)
4023** then the conversion is performed. Otherwise no conversion occurs.
4024** The [SQLITE_INTEGER | datatype] after conversion is returned.
4025**
4026** Please pay particular attention to the fact that the pointer returned
4027** from [sqlite3_value_blob()], [sqlite3_value_text()], or
4028** [sqlite3_value_text16()] can be invalidated by a subsequent call to
4029** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
4030** or [sqlite3_value_text16()].
4031**
4032** These routines must be called from the same thread as
4033** the SQL function that supplied the [sqlite3_value*] parameters.
4034**
4035** INVARIANTS:
4036**
4037** {H15103} The [sqlite3_value_blob(V)] interface converts the
4038** [protected sqlite3_value] object V into a BLOB and then
4039** returns a pointer to the converted value.
4040**
4041** {H15106} The [sqlite3_value_bytes(V)] interface returns the
4042** number of bytes in the BLOB or string (exclusive of the
4043** zero terminator on the string) that was returned by the
4044** most recent call to [sqlite3_value_blob(V)] or
4045** [sqlite3_value_text(V)].
4046**
4047** {H15109} The [sqlite3_value_bytes16(V)] interface returns the
4048** number of bytes in the string (exclusive of the
4049** zero terminator on the string) that was returned by the
4050** most recent call to [sqlite3_value_text16(V)],
4051** [sqlite3_value_text16be(V)], or [sqlite3_value_text16le(V)].
4052**
4053** {H15112} The [sqlite3_value_double(V)] interface converts the
4054** [protected sqlite3_value] object V into a floating point value and
4055** returns a copy of that value.
4056**
4057** {H15115} The [sqlite3_value_int(V)] interface converts the
4058** [protected sqlite3_value] object V into a 64-bit signed integer and
4059** returns the lower 32 bits of that integer.
4060**
4061** {H15118} The [sqlite3_value_int64(V)] interface converts the
4062** [protected sqlite3_value] object V into a 64-bit signed integer and
4063** returns a copy of that integer.
4064**
4065** {H15121} The [sqlite3_value_text(V)] interface converts the
4066** [protected sqlite3_value] object V into a zero-terminated UTF-8
4067** string and returns a pointer to that string.
4068**
4069** {H15124} The [sqlite3_value_text16(V)] interface converts the
4070** [protected sqlite3_value] object V into a zero-terminated 2-byte
4071** aligned UTF-16 native byte order
4072** string and returns a pointer to that string.
4073**
4074** {H15127} The [sqlite3_value_text16be(V)] interface converts the
4075** [protected sqlite3_value] object V into a zero-terminated 2-byte
4076** aligned UTF-16 big-endian
4077** string and returns a pointer to that string.
4078**
4079** {H15130} The [sqlite3_value_text16le(V)] interface converts the
4080** [protected sqlite3_value] object V into a zero-terminated 2-byte
4081** aligned UTF-16 little-endian
4082** string and returns a pointer to that string.
4083**
4084** {H15133} The [sqlite3_value_type(V)] interface returns
4085** one of [SQLITE_NULL], [SQLITE_INTEGER], [SQLITE_FLOAT],
4086** [SQLITE_TEXT], or [SQLITE_BLOB] as appropriate for
4087** the [sqlite3_value] object V.
4088**
4089** {H15136} The [sqlite3_value_numeric_type(V)] interface converts
4090** the [protected sqlite3_value] object V into either an integer or
4091** a floating point value if it can do so without loss of
4092** information, and returns one of [SQLITE_NULL],
4093** [SQLITE_INTEGER], [SQLITE_FLOAT], [SQLITE_TEXT], or
4094** [SQLITE_BLOB] as appropriate for the
4095** [protected sqlite3_value] object V after the conversion attempt.
4096*/
4097const void *sqlite3_value_blob(sqlite3_value*);
4098int sqlite3_value_bytes(sqlite3_value*);
4099int sqlite3_value_bytes16(sqlite3_value*);
4100double sqlite3_value_double(sqlite3_value*);
4101int sqlite3_value_int(sqlite3_value*);
4102sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
4103const unsigned char *sqlite3_value_text(sqlite3_value*);
4104const void *sqlite3_value_text16(sqlite3_value*);
4105const void *sqlite3_value_text16le(sqlite3_value*);
4106const void *sqlite3_value_text16be(sqlite3_value*);
4107int sqlite3_value_type(sqlite3_value*);
4108int sqlite3_value_numeric_type(sqlite3_value*);
4109
4110/*
4111** CAPI3REF: Obtain Aggregate Function Context {H16210} <S20200>
4112**
4113** The implementation of aggregate SQL functions use this routine to allocate
4114** a structure for storing their state.
4115**
4116** The first time the sqlite3_aggregate_context() routine is called for a
4117** particular aggregate, SQLite allocates nBytes of memory, zeroes out that
4118** memory, and returns a pointer to it. On second and subsequent calls to
4119** sqlite3_aggregate_context() for the same aggregate function index,
4120** the same buffer is returned. The implementation of the aggregate can use
4121** the returned buffer to accumulate data.
4122**
4123** SQLite automatically frees the allocated buffer when the aggregate
4124** query concludes.
4125**
4126** The first parameter should be a copy of the
4127** [sqlite3_context | SQL function context] that is the first parameter
4128** to the callback routine that implements the aggregate function.
4129**
4130** This routine must be called from the same thread in which
4131** the aggregate SQL function is running.
4132**
4133** INVARIANTS:
4134**
4135** {H16211} The first invocation of [sqlite3_aggregate_context(C,N)] for
4136** a particular instance of an aggregate function (for a particular
4137** context C) causes SQLite to allocate N bytes of memory,
4138** zero that memory, and return a pointer to the allocated memory.
4139**
4140** {H16213} If a memory allocation error occurs during
4141** [sqlite3_aggregate_context(C,N)] then the function returns 0.
4142**
4143** {H16215} Second and subsequent invocations of
4144** [sqlite3_aggregate_context(C,N)] for the same context pointer C
4145** ignore the N parameter and return a pointer to the same
4146** block of memory returned by the first invocation.
4147**
4148** {H16217} The memory allocated by [sqlite3_aggregate_context(C,N)] is
4149** automatically freed on the next call to [sqlite3_reset()]
4150** or [sqlite3_finalize()] for the [prepared statement] containing
4151** the aggregate function associated with context C.
4152*/
4153void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
4154
4155/*
4156** CAPI3REF: User Data For Functions {H16240} <S20200>
4157**
4158** The sqlite3_user_data() interface returns a copy of
4159** the pointer that was the pUserData parameter (the 5th parameter)
4160** of the [sqlite3_create_function()]
4161** and [sqlite3_create_function16()] routines that originally
4162** registered the application defined function. {END}
4163**
4164** This routine must be called from the same thread in which
4165** the application-defined function is running.
4166**
4167** INVARIANTS:
4168**
4169** {H16243} The [sqlite3_user_data(C)] interface returns a copy of the
4170** P pointer from the [sqlite3_create_function(D,X,N,E,P,F,S,L)]
4171** or [sqlite3_create_function16(D,X,N,E,P,F,S,L)] call that
4172** registered the SQL function associated with [sqlite3_context] C.
4173*/
4174void *sqlite3_user_data(sqlite3_context*);
4175
4176/*
4177** CAPI3REF: Database Connection For Functions {H16250} <S60600><S20200>
4178**
4179** The sqlite3_context_db_handle() interface returns a copy of
4180** the pointer to the [database connection] (the 1st parameter)
4181** of the [sqlite3_create_function()]
4182** and [sqlite3_create_function16()] routines that originally
4183** registered the application defined function.
4184**
4185** INVARIANTS:
4186**
4187** {H16253} The [sqlite3_context_db_handle(C)] interface returns a copy of the
4188** D pointer from the [sqlite3_create_function(D,X,N,E,P,F,S,L)]
4189** or [sqlite3_create_function16(D,X,N,E,P,F,S,L)] call that
4190** registered the SQL function associated with [sqlite3_context] C.
4191*/
4192sqlite3 *sqlite3_context_db_handle(sqlite3_context*);
4193
4194/*
4195** CAPI3REF: Function Auxiliary Data {H16270} <S20200>
4196**
4197** The following two functions may be used by scalar SQL functions to
4198** associate metadata with argument values. If the same value is passed to
4199** multiple invocations of the same SQL function during query execution, under
4200** some circumstances the associated metadata may be preserved. This may
4201** be used, for example, to add a regular-expression matching scalar
4202** function. The compiled version of the regular expression is stored as
4203** metadata associated with the SQL value passed as the regular expression
4204** pattern. The compiled regular expression can be reused on multiple
4205** invocations of the same function so that the original pattern string
4206** does not need to be recompiled on each invocation.
4207**
4208** The sqlite3_get_auxdata() interface returns a pointer to the metadata
4209** associated by the sqlite3_set_auxdata() function with the Nth argument
4210** value to the application-defined function. If no metadata has been ever
4211** been set for the Nth argument of the function, or if the corresponding
4212** function parameter has changed since the meta-data was set,
4213** then sqlite3_get_auxdata() returns a NULL pointer.
4214**
4215** The sqlite3_set_auxdata() interface saves the metadata
4216** pointed to by its 3rd parameter as the metadata for the N-th
4217** argument of the application-defined function. Subsequent
4218** calls to sqlite3_get_auxdata() might return this data, if it has
4219** not been destroyed.
4220** If it is not NULL, SQLite will invoke the destructor
4221** function given by the 4th parameter to sqlite3_set_auxdata() on
4222** the metadata when the corresponding function parameter changes
4223** or when the SQL statement completes, whichever comes first.
4224**
4225** SQLite is free to call the destructor and drop metadata on any
4226** parameter of any function at any time. The only guarantee is that
4227** the destructor will be called before the metadata is dropped.
4228**
4229** In practice, metadata is preserved between function calls for
4230** expressions that are constant at compile time. This includes literal
4231** values and SQL variables.
4232**
4233** These routines must be called from the same thread in which
4234** the SQL function is running.
4235**
4236** INVARIANTS:
4237**
4238** {H16272} The [sqlite3_get_auxdata(C,N)] interface returns a pointer
4239** to metadata associated with the Nth parameter of the SQL function
4240** whose context is C, or NULL if there is no metadata associated
4241** with that parameter.
4242**
4243** {H16274} The [sqlite3_set_auxdata(C,N,P,D)] interface assigns a metadata
4244** pointer P to the Nth parameter of the SQL function with context C.
4245**
4246** {H16276} SQLite will invoke the destructor D with a single argument
4247** which is the metadata pointer P following a call to
4248** [sqlite3_set_auxdata(C,N,P,D)] when SQLite ceases to hold
4249** the metadata.
4250**
4251** {H16277} SQLite ceases to hold metadata for an SQL function parameter
4252** when the value of that parameter changes.
4253**
4254** {H16278} When [sqlite3_set_auxdata(C,N,P,D)] is invoked, the destructor
4255** is called for any prior metadata associated with the same function
4256** context C and parameter N.
4257**
4258** {H16279} SQLite will call destructors for any metadata it is holding
4259** in a particular [prepared statement] S when either
4260** [sqlite3_reset(S)] or [sqlite3_finalize(S)] is called.
4261*/
4262void *sqlite3_get_auxdata(sqlite3_context*, int N);
4263void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
4264
4265
4266/*
4267** CAPI3REF: Constants Defining Special Destructor Behavior {H10280} <S30100>
4268**
4269** These are special values for the destructor that is passed in as the
4270** final argument to routines like [sqlite3_result_blob()]. If the destructor
4271** argument is SQLITE_STATIC, it means that the content pointer is constant
4272** and will never change. It does not need to be destroyed. The
4273** SQLITE_TRANSIENT value means that the content will likely change in
4274** the near future and that SQLite should make its own private copy of
4275** the content before returning.
4276**
4277** The typedef is necessary to work around problems in certain
4278** C++ compilers. See ticket #2191.
4279*/
4280typedef void (*sqlite3_destructor_type)(void*);
4281#define SQLITE_STATIC ((sqlite3_destructor_type)0)
4282#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1)
4283
4284/*
4285** CAPI3REF: Setting The Result Of An SQL Function {H16400} <S20200>
4286**
4287** These routines are used by the xFunc or xFinal callbacks that
4288** implement SQL functions and aggregates. See
4289** [sqlite3_create_function()] and [sqlite3_create_function16()]
4290** for additional information.
4291**
4292** These functions work very much like the [parameter binding] family of
4293** functions used to bind values to host parameters in prepared statements.
4294** Refer to the [SQL parameter] documentation for additional information.
4295**
4296** The sqlite3_result_blob() interface sets the result from
4297** an application-defined function to be the BLOB whose content is pointed
4298** to by the second parameter and which is N bytes long where N is the
4299** third parameter.
4300**
4301** The sqlite3_result_zeroblob() interfaces set the result of
4302** the application-defined function to be a BLOB containing all zero
4303** bytes and N bytes in size, where N is the value of the 2nd parameter.
4304**
4305** The sqlite3_result_double() interface sets the result from
4306** an application-defined function to be a floating point value specified
4307** by its 2nd argument.
4308**
4309** The sqlite3_result_error() and sqlite3_result_error16() functions
4310** cause the implemented SQL function to throw an exception.
4311** SQLite uses the string pointed to by the
4312** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
4313** as the text of an error message. SQLite interprets the error
4314** message string from sqlite3_result_error() as UTF-8. SQLite
4315** interprets the string from sqlite3_result_error16() as UTF-16 in native
4316** byte order. If the third parameter to sqlite3_result_error()
4317** or sqlite3_result_error16() is negative then SQLite takes as the error
4318** message all text up through the first zero character.
4319** If the third parameter to sqlite3_result_error() or
4320** sqlite3_result_error16() is non-negative then SQLite takes that many
4321** bytes (not characters) from the 2nd parameter as the error message.
4322** The sqlite3_result_error() and sqlite3_result_error16()
4323** routines make a private copy of the error message text before
4324** they return. Hence, the calling function can deallocate or
4325** modify the text after they return without harm.
4326** The sqlite3_result_error_code() function changes the error code
4327** returned by SQLite as a result of an error in a function. By default,
4328** the error code is SQLITE_ERROR. A subsequent call to sqlite3_result_error()
4329** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
4330**
4331** The sqlite3_result_toobig() interface causes SQLite to throw an error
4332** indicating that a string or BLOB is to long to represent.
4333**
4334** The sqlite3_result_nomem() interface causes SQLite to throw an error
4335** indicating that a memory allocation failed.
4336**
4337** The sqlite3_result_int() interface sets the return value
4338** of the application-defined function to be the 32-bit signed integer
4339** value given in the 2nd argument.
4340** The sqlite3_result_int64() interface sets the return value
4341** of the application-defined function to be the 64-bit signed integer
4342** value given in the 2nd argument.
4343**
4344** The sqlite3_result_null() interface sets the return value
4345** of the application-defined function to be NULL.
4346**
4347** The sqlite3_result_text(), sqlite3_result_text16(),
4348** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
4349** set the return value of the application-defined function to be
4350** a text string which is represented as UTF-8, UTF-16 native byte order,
4351** UTF-16 little endian, or UTF-16 big endian, respectively.
4352** SQLite takes the text result from the application from
4353** the 2nd parameter of the sqlite3_result_text* interfaces.
4354** If the 3rd parameter to the sqlite3_result_text* interfaces
4355** is negative, then SQLite takes result text from the 2nd parameter
4356** through the first zero character.
4357** If the 3rd parameter to the sqlite3_result_text* interfaces
4358** is non-negative, then as many bytes (not characters) of the text
4359** pointed to by the 2nd parameter are taken as the application-defined
4360** function result.
4361** If the 4th parameter to the sqlite3_result_text* interfaces
4362** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
4363** function as the destructor on the text or BLOB result when it has
4364** finished using that result.
4365** If the 4th parameter to the sqlite3_result_text* interfaces or
4366** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
4367** assumes that the text or BLOB result is in constant space and does not
4368** copy the it or call a destructor when it has finished using that result.
4369** If the 4th parameter to the sqlite3_result_text* interfaces
4370** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
4371** then SQLite makes a copy of the result into space obtained from
4372** from [sqlite3_malloc()] before it returns.
4373**
4374** The sqlite3_result_value() interface sets the result of
4375** the application-defined function to be a copy the
4376** [unprotected sqlite3_value] object specified by the 2nd parameter. The
4377** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
4378** so that the [sqlite3_value] specified in the parameter may change or
4379** be deallocated after sqlite3_result_value() returns without harm.
4380** A [protected sqlite3_value] object may always be used where an
4381** [unprotected sqlite3_value] object is required, so either
4382** kind of [sqlite3_value] object can be used with this interface.
4383**
4384** If these routines are called from within the different thread
4385** than the one containing the application-defined function that received
4386** the [sqlite3_context] pointer, the results are undefined.
4387**
4388** INVARIANTS:
4389**
4390** {H16403} The default return value from any SQL function is NULL.
4391**
4392** {H16406} The [sqlite3_result_blob(C,V,N,D)] interface changes the
4393** return value of function C to be a BLOB that is N bytes
4394** in length and with content pointed to by V.
4395**
4396** {H16409} The [sqlite3_result_double(C,V)] interface changes the
4397** return value of function C to be the floating point value V.
4398**
4399** {H16412} The [sqlite3_result_error(C,V,N)] interface changes the return
4400** value of function C to be an exception with error code
4401** [SQLITE_ERROR] and a UTF-8 error message copied from V up to the
4402** first zero byte or until N bytes are read if N is positive.
4403**
4404** {H16415} The [sqlite3_result_error16(C,V,N)] interface changes the return
4405** value of function C to be an exception with error code
4406** [SQLITE_ERROR] and a UTF-16 native byte order error message
4407** copied from V up to the first zero terminator or until N bytes
4408** are read if N is positive.
4409**
4410** {H16418} The [sqlite3_result_error_toobig(C)] interface changes the return
4411** value of the function C to be an exception with error code
4412** [SQLITE_TOOBIG] and an appropriate error message.
4413**
4414** {H16421} The [sqlite3_result_error_nomem(C)] interface changes the return
4415** value of the function C to be an exception with error code
4416** [SQLITE_NOMEM] and an appropriate error message.
4417**
4418** {H16424} The [sqlite3_result_error_code(C,E)] interface changes the return
4419** value of the function C to be an exception with error code E.
4420** The error message text is unchanged.
4421**
4422** {H16427} The [sqlite3_result_int(C,V)] interface changes the
4423** return value of function C to be the 32-bit integer value V.
4424**
4425** {H16430} The [sqlite3_result_int64(C,V)] interface changes the
4426** return value of function C to be the 64-bit integer value V.
4427**
4428** {H16433} The [sqlite3_result_null(C)] interface changes the
4429** return value of function C to be NULL.
4430**
4431** {H16436} The [sqlite3_result_text(C,V,N,D)] interface changes the
4432** return value of function C to be the UTF-8 string
4433** V up to the first zero if N is negative
4434** or the first N bytes of V if N is non-negative.
4435**
4436** {H16439} The [sqlite3_result_text16(C,V,N,D)] interface changes the
4437** return value of function C to be the UTF-16 native byte order
4438** string V up to the first zero if N is negative
4439** or the first N bytes of V if N is non-negative.
4440**
4441** {H16442} The [sqlite3_result_text16be(C,V,N,D)] interface changes the
4442** return value of function C to be the UTF-16 big-endian
4443** string V up to the first zero if N is negative
4444** or the first N bytes or V if N is non-negative.
4445**
4446** {H16445} The [sqlite3_result_text16le(C,V,N,D)] interface changes the
4447** return value of function C to be the UTF-16 little-endian
4448** string V up to the first zero if N is negative
4449** or the first N bytes of V if N is non-negative.
4450**
4451** {H16448} The [sqlite3_result_value(C,V)] interface changes the
4452** return value of function C to be the [unprotected sqlite3_value]
4453** object V.
4454**
4455** {H16451} The [sqlite3_result_zeroblob(C,N)] interface changes the
4456** return value of function C to be an N-byte BLOB of all zeros.
4457**
4458** {H16454} The [sqlite3_result_error()] and [sqlite3_result_error16()]
4459** interfaces make a copy of their error message strings before
4460** returning.
4461**
4462** {H16457} If the D destructor parameter to [sqlite3_result_blob(C,V,N,D)],
4463** [sqlite3_result_text(C,V,N,D)], [sqlite3_result_text16(C,V,N,D)],
4464** [sqlite3_result_text16be(C,V,N,D)], or
4465** [sqlite3_result_text16le(C,V,N,D)] is the constant [SQLITE_STATIC]
4466** then no destructor is ever called on the pointer V and SQLite
4467** assumes that V is immutable.
4468**
4469** {H16460} If the D destructor parameter to [sqlite3_result_blob(C,V,N,D)],
4470** [sqlite3_result_text(C,V,N,D)], [sqlite3_result_text16(C,V,N,D)],
4471** [sqlite3_result_text16be(C,V,N,D)], or
4472** [sqlite3_result_text16le(C,V,N,D)] is the constant
4473** [SQLITE_TRANSIENT] then the interfaces makes a copy of the
4474** content of V and retains the copy.
4475**
4476** {H16463} If the D destructor parameter to [sqlite3_result_blob(C,V,N,D)],
4477** [sqlite3_result_text(C,V,N,D)], [sqlite3_result_text16(C,V,N,D)],
4478** [sqlite3_result_text16be(C,V,N,D)], or
4479** [sqlite3_result_text16le(C,V,N,D)] is some value other than
4480** the constants [SQLITE_STATIC] and [SQLITE_TRANSIENT] then
4481** SQLite will invoke the destructor D with V as its only argument
4482** when it has finished with the V value.
4483*/
4484void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
4485void sqlite3_result_double(sqlite3_context*, double);
4486void sqlite3_result_error(sqlite3_context*, const char*, int);
4487void sqlite3_result_error16(sqlite3_context*, const void*, int);
4488void sqlite3_result_error_toobig(sqlite3_context*);
4489void sqlite3_result_error_nomem(sqlite3_context*);
4490void sqlite3_result_error_code(sqlite3_context*, int);
4491void sqlite3_result_int(sqlite3_context*, int);
4492void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
4493void sqlite3_result_null(sqlite3_context*);
4494void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
4495void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
4496void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
4497void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
4498void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
4499void sqlite3_result_zeroblob(sqlite3_context*, int n);
4500
4501/*
4502** CAPI3REF: Define New Collating Sequences {H16600} <S20300>
4503**
4504** These functions are used to add new collation sequences to the
4505** [database connection] specified as the first argument.
4506**
4507** The name of the new collation sequence is specified as a UTF-8 string
4508** for sqlite3_create_collation() and sqlite3_create_collation_v2()
4509** and a UTF-16 string for sqlite3_create_collation16(). In all cases
4510** the name is passed as the second function argument.
4511**
4512** The third argument may be one of the constants [SQLITE_UTF8],
4513** [SQLITE_UTF16LE] or [SQLITE_UTF16BE], indicating that the user-supplied
4514** routine expects to be passed pointers to strings encoded using UTF-8,
4515** UTF-16 little-endian, or UTF-16 big-endian, respectively. The
4516** third argument might also be [SQLITE_UTF16_ALIGNED] to indicate that
4517** the routine expects pointers to 16-bit word aligned strings
4518** of UTF-16 in the native byte order of the host computer.
4519**
4520** A pointer to the user supplied routine must be passed as the fifth
4521** argument. If it is NULL, this is the same as deleting the collation
4522** sequence (so that SQLite cannot call it anymore).
4523** Each time the application supplied function is invoked, it is passed
4524** as its first parameter a copy of the void* passed as the fourth argument
4525** to sqlite3_create_collation() or sqlite3_create_collation16().
4526**
4527** The remaining arguments to the application-supplied routine are two strings,
4528** each represented by a (length, data) pair and encoded in the encoding
4529** that was passed as the third argument when the collation sequence was
4530** registered. {END} The application defined collation routine should
4531** return negative, zero or positive if the first string is less than,
4532** equal to, or greater than the second string. i.e. (STRING1 - STRING2).
4533**
4534** The sqlite3_create_collation_v2() works like sqlite3_create_collation()
4535** except that it takes an extra argument which is a destructor for
4536** the collation. The destructor is called when the collation is
4537** destroyed and is passed a copy of the fourth parameter void* pointer
4538** of the sqlite3_create_collation_v2().
4539** Collations are destroyed when they are overridden by later calls to the
4540** collation creation functions or when the [database connection] is closed
4541** using [sqlite3_close()].
4542**
4543** INVARIANTS:
4544**
4545** {H16603} A successful call to the
4546** [sqlite3_create_collation_v2(B,X,E,P,F,D)] interface
4547** registers function F as the comparison function used to
4548** implement collation X on the [database connection] B for
4549** databases having encoding E.
4550**
4551** {H16604} SQLite understands the X parameter to
4552** [sqlite3_create_collation_v2(B,X,E,P,F,D)] as a zero-terminated
4553** UTF-8 string in which case is ignored for ASCII characters and
4554** is significant for non-ASCII characters.
4555**
4556** {H16606} Successive calls to [sqlite3_create_collation_v2(B,X,E,P,F,D)]
4557** with the same values for B, X, and E, override prior values
4558** of P, F, and D.
4559**
4560** {H16609} If the destructor D in [sqlite3_create_collation_v2(B,X,E,P,F,D)]
4561** is not NULL then it is called with argument P when the
4562** collating function is dropped by SQLite.
4563**
4564** {H16612} A collating function is dropped when it is overloaded.
4565**
4566** {H16615} A collating function is dropped when the database connection
4567** is closed using [sqlite3_close()].
4568**
4569** {H16618} The pointer P in [sqlite3_create_collation_v2(B,X,E,P,F,D)]
4570** is passed through as the first parameter to the comparison
4571** function F for all subsequent invocations of F.
4572**
4573** {H16621} A call to [sqlite3_create_collation(B,X,E,P,F)] is exactly
4574** the same as a call to [sqlite3_create_collation_v2()] with
4575** the same parameters and a NULL destructor.
4576**
4577** {H16624} Following a [sqlite3_create_collation_v2(B,X,E,P,F,D)],
4578** SQLite uses the comparison function F for all text comparison
4579** operations on the [database connection] B on text values that
4580** use the collating sequence named X.
4581**
4582** {H16627} The [sqlite3_create_collation16(B,X,E,P,F)] works the same
4583** as [sqlite3_create_collation(B,X,E,P,F)] except that the
4584** collation name X is understood as UTF-16 in native byte order
4585** instead of UTF-8.
4586**
4587** {H16630} When multiple comparison functions are available for the same
4588** collating sequence, SQLite chooses the one whose text encoding
4589** requires the least amount of conversion from the default
4590** text encoding of the database.
4591*/
4592int sqlite3_create_collation(
4593 sqlite3*,
4594 const char *zName,
4595 int eTextRep,
4596 void*,
4597 int(*xCompare)(void*,int,const void*,int,const void*)
4598);
4599int sqlite3_create_collation_v2(
4600 sqlite3*,
4601 const char *zName,
4602 int eTextRep,
4603 void*,
4604 int(*xCompare)(void*,int,const void*,int,const void*),
4605 void(*xDestroy)(void*)
4606);
4607int sqlite3_create_collation16(
4608 sqlite3*,
4609 const void *zName,
4610 int eTextRep,
4611 void*,
4612 int(*xCompare)(void*,int,const void*,int,const void*)
4613);
4614
4615/*
4616** CAPI3REF: Collation Needed Callbacks {H16700} <S20300>
4617**
4618** To avoid having to register all collation sequences before a database
4619** can be used, a single callback function may be registered with the
4620** [database connection] to be called whenever an undefined collation
4621** sequence is required.
4622**
4623** If the function is registered using the sqlite3_collation_needed() API,
4624** then it is passed the names of undefined collation sequences as strings
4625** encoded in UTF-8. {H16703} If sqlite3_collation_needed16() is used,
4626** the names are passed as UTF-16 in machine native byte order.
4627** A call to either function replaces any existing callback.
4628**
4629** When the callback is invoked, the first argument passed is a copy
4630** of the second argument to sqlite3_collation_needed() or
4631** sqlite3_collation_needed16(). The second argument is the database
4632** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
4633** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
4634** sequence function required. The fourth parameter is the name of the
4635** required collation sequence.
4636**
4637** The callback function should register the desired collation using
4638** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
4639** [sqlite3_create_collation_v2()].
4640**
4641** INVARIANTS:
4642**
4643** {H16702} A successful call to [sqlite3_collation_needed(D,P,F)]
4644** or [sqlite3_collation_needed16(D,P,F)] causes
4645** the [database connection] D to invoke callback F with first
4646** parameter P whenever it needs a comparison function for a
4647** collating sequence that it does not know about.
4648**
4649** {H16704} Each successful call to [sqlite3_collation_needed()] or
4650** [sqlite3_collation_needed16()] overrides the callback registered
4651** on the same [database connection] by prior calls to either
4652** interface.
4653**
4654** {H16706} The name of the requested collating function passed in the
4655** 4th parameter to the callback is in UTF-8 if the callback
4656** was registered using [sqlite3_collation_needed()] and
4657** is in UTF-16 native byte order if the callback was
4658** registered using [sqlite3_collation_needed16()].
4659*/
4660int sqlite3_collation_needed(
4661 sqlite3*,
4662 void*,
4663 void(*)(void*,sqlite3*,int eTextRep,const char*)
4664);
4665int sqlite3_collation_needed16(
4666 sqlite3*,
4667 void*,
4668 void(*)(void*,sqlite3*,int eTextRep,const void*)
4669);
4670
4671/*
4672** Specify the key for an encrypted database. This routine should be
4673** called right after sqlite3_open().
4674**
4675** The code to implement this API is not available in the public release
4676** of SQLite.
4677*/
4678int sqlite3_key(
4679 sqlite3 *db, /* Database to be rekeyed */
4680 const void *pKey, int nKey /* The key */
4681);
4682
4683/*
4684** Change the key on an open database. If the current database is not
4685** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the
4686** database is decrypted.
4687**
4688** The code to implement this API is not available in the public release
4689** of SQLite.
4690*/
4691int sqlite3_rekey(
4692 sqlite3 *db, /* Database to be rekeyed */
4693 const void *pKey, int nKey /* The new key */
4694);
4695
4696/*
4697** CAPI3REF: Suspend Execution For A Short Time {H10530} <S40410>
4698**
4699** The sqlite3_sleep() function causes the current thread to suspend execution
4700** for at least a number of milliseconds specified in its parameter.
4701**
4702** If the operating system does not support sleep requests with
4703** millisecond time resolution, then the time will be rounded up to
4704** the nearest second. The number of milliseconds of sleep actually
4705** requested from the operating system is returned.
4706**
4707** SQLite implements this interface by calling the xSleep()
4708** method of the default [sqlite3_vfs] object.
4709**
4710** INVARIANTS:
4711**
4712** {H10533} The [sqlite3_sleep(M)] interface invokes the xSleep
4713** method of the default [sqlite3_vfs|VFS] in order to
4714** suspend execution of the current thread for at least
4715** M milliseconds.
4716**
4717** {H10536} The [sqlite3_sleep(M)] interface returns the number of
4718** milliseconds of sleep actually requested of the operating
4719** system, which might be larger than the parameter M.
4720*/
4721int sqlite3_sleep(int);
4722
4723/*
4724** CAPI3REF: Name Of The Folder Holding Temporary Files {H10310} <S20000>
4725**
4726** If this global variable is made to point to a string which is
4727** the name of a folder (a.k.a. directory), then all temporary files
4728** created by SQLite will be placed in that directory. If this variable
4729** is a NULL pointer, then SQLite performs a search for an appropriate
4730** temporary file directory.
4731**
4732** It is not safe to modify this variable once a [database connection]
4733** has been opened. It is intended that this variable be set once
4734** as part of process initialization and before any SQLite interface
4735** routines have been call and remain unchanged thereafter.
4736*/
4737SQLITE_EXTERN char *sqlite3_temp_directory;
4738
4739/*
4740** CAPI3REF: Test For Auto-Commit Mode {H12930} <S60200>
4741** KEYWORDS: {autocommit mode}
4742**
4743** The sqlite3_get_autocommit() interface returns non-zero or
4744** zero if the given database connection is or is not in autocommit mode,
4745** respectively. Autocommit mode is on by default.
4746** Autocommit mode is disabled by a [BEGIN] statement.
4747** Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
4748**
4749** If certain kinds of errors occur on a statement within a multi-statement
4750** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
4751** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
4752** transaction might be rolled back automatically. The only way to
4753** find out whether SQLite automatically rolled back the transaction after
4754** an error is to use this function.
4755**
4756** INVARIANTS:
4757**
4758** {H12931} The [sqlite3_get_autocommit(D)] interface returns non-zero or
4759** zero if the [database connection] D is or is not in autocommit
4760** mode, respectively.
4761**
4762** {H12932} Autocommit mode is on by default.
4763**
4764** {H12933} Autocommit mode is disabled by a successful [BEGIN] statement.
4765**
4766** {H12934} Autocommit mode is enabled by a successful [COMMIT] or [ROLLBACK]
4767** statement.
4768**
4769** ASSUMPTIONS:
4770**
4771** {A12936} If another thread changes the autocommit status of the database
4772** connection while this routine is running, then the return value
4773** is undefined.
4774*/
4775int sqlite3_get_autocommit(sqlite3*);
4776
4777/*
4778** CAPI3REF: Find The Database Handle Of A Prepared Statement {H13120} <S60600>
4779**
4780** The sqlite3_db_handle interface returns the [database connection] handle
4781** to which a [prepared statement] belongs. The database handle returned by
4782** sqlite3_db_handle is the same database handle that was the first argument
4783** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
4784** create the statement in the first place.
4785**
4786** INVARIANTS:
4787**
4788** {H13123} The [sqlite3_db_handle(S)] interface returns a pointer
4789** to the [database connection] associated with the
4790** [prepared statement] S.
4791*/
4792sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
4793
4794/*
4795** CAPI3REF: Find the next prepared statement {H13140} <S60600>
4796**
4797** This interface returns a pointer to the next [prepared statement] after
4798** pStmt associated with the [database connection] pDb. If pStmt is NULL
4799** then this interface returns a pointer to the first prepared statement
4800** associated with the database connection pDb. If no prepared statement
4801** satisfies the conditions of this routine, it returns NULL.
4802**
4803** INVARIANTS:
4804**
4805** {H13143} If D is a [database connection] that holds one or more
4806** unfinalized [prepared statements] and S is a NULL pointer,
4807** then [sqlite3_next_stmt(D, S)] routine shall return a pointer
4808** to one of the prepared statements associated with D.
4809**
4810** {H13146} If D is a [database connection] that holds no unfinalized
4811** [prepared statements] and S is a NULL pointer, then
4812** [sqlite3_next_stmt(D, S)] routine shall return a NULL pointer.
4813**
4814** {H13149} If S is a [prepared statement] in the [database connection] D
4815** and S is not the last prepared statement in D, then
4816** [sqlite3_next_stmt(D, S)] routine shall return a pointer
4817** to the next prepared statement in D after S.
4818**
4819** {H13152} If S is the last [prepared statement] in the
4820** [database connection] D then the [sqlite3_next_stmt(D, S)]
4821** routine shall return a NULL pointer.
4822**
4823** ASSUMPTIONS:
4824**
4825** {A13154} The [database connection] pointer D in a call to
4826** [sqlite3_next_stmt(D,S)] must refer to an open database
4827** connection and in particular must not be a NULL pointer.
4828*/
4829sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
4830
4831/*
4832** CAPI3REF: Commit And Rollback Notification Callbacks {H12950} <S60400>
4833**
4834** The sqlite3_commit_hook() interface registers a callback
4835** function to be invoked whenever a transaction is committed.
4836** Any callback set by a previous call to sqlite3_commit_hook()
4837** for the same database connection is overridden.
4838** The sqlite3_rollback_hook() interface registers a callback
4839** function to be invoked whenever a transaction is committed.
4840** Any callback set by a previous call to sqlite3_commit_hook()
4841** for the same database connection is overridden.
4842** The pArg argument is passed through to the callback.
4843** If the callback on a commit hook function returns non-zero,
4844** then the commit is converted into a rollback.
4845**
4846** If another function was previously registered, its
4847** pArg value is returned. Otherwise NULL is returned.
4848**
4849** Registering a NULL function disables the callback.
4850**
4851** For the purposes of this API, a transaction is said to have been
4852** rolled back if an explicit "ROLLBACK" statement is executed, or
4853** an error or constraint causes an implicit rollback to occur.
4854** The rollback callback is not invoked if a transaction is
4855** automatically rolled back because the database connection is closed.
4856** The rollback callback is not invoked if a transaction is
4857** rolled back because a commit callback returned non-zero.
4858** <todo> Check on this </todo>
4859**
4860** INVARIANTS:
4861**
4862** {H12951} The [sqlite3_commit_hook(D,F,P)] interface registers the
4863** callback function F to be invoked with argument P whenever
4864** a transaction commits on the [database connection] D.
4865**
4866** {H12952} The [sqlite3_commit_hook(D,F,P)] interface returns the P argument
4867** from the previous call with the same [database connection] D,
4868** or NULL on the first call for a particular database connection D.
4869**
4870** {H12953} Each call to [sqlite3_commit_hook()] overwrites the callback
4871** registered by prior calls.
4872**
4873** {H12954} If the F argument to [sqlite3_commit_hook(D,F,P)] is NULL
4874** then the commit hook callback is canceled and no callback
4875** is invoked when a transaction commits.
4876**
4877** {H12955} If the commit callback returns non-zero then the commit is
4878** converted into a rollback.
4879**
4880** {H12961} The [sqlite3_rollback_hook(D,F,P)] interface registers the
4881** callback function F to be invoked with argument P whenever
4882** a transaction rolls back on the [database connection] D.
4883**
4884** {H12962} The [sqlite3_rollback_hook(D,F,P)] interface returns the P
4885** argument from the previous call with the same
4886** [database connection] D, or NULL on the first call
4887** for a particular database connection D.
4888**
4889** {H12963} Each call to [sqlite3_rollback_hook()] overwrites the callback
4890** registered by prior calls.
4891**
4892** {H12964} If the F argument to [sqlite3_rollback_hook(D,F,P)] is NULL
4893** then the rollback hook callback is canceled and no callback
4894** is invoked when a transaction rolls back.
4895*/
4896void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
4897void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
4898
4899/*
4900** CAPI3REF: Data Change Notification Callbacks {H12970} <S60400>
4901**
4902** The sqlite3_update_hook() interface registers a callback function
4903** with the [database connection] identified by the first argument
4904** to be invoked whenever a row is updated, inserted or deleted.
4905** Any callback set by a previous call to this function
4906** for the same database connection is overridden.
4907**
4908** The second argument is a pointer to the function to invoke when a
4909** row is updated, inserted or deleted.
4910** The first argument to the callback is a copy of the third argument
4911** to sqlite3_update_hook().
4912** The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
4913** or [SQLITE_UPDATE], depending on the operation that caused the callback
4914** to be invoked.
4915** The third and fourth arguments to the callback contain pointers to the
4916** database and table name containing the affected row.
4917** The final callback parameter is the rowid of the row. In the case of
4918** an update, this is the rowid after the update takes place.
4919**
4920** The update hook is not invoked when internal system tables are
4921** modified (i.e. sqlite_master and sqlite_sequence).
4922**
4923** If another function was previously registered, its pArg value
4924** is returned. Otherwise NULL is returned.
4925**
4926** INVARIANTS:
4927**
4928** {H12971} The [sqlite3_update_hook(D,F,P)] interface causes the callback
4929** function F to be invoked with first parameter P whenever
4930** a table row is modified, inserted, or deleted on
4931** the [database connection] D.
4932**
4933** {H12973} The [sqlite3_update_hook(D,F,P)] interface returns the value
4934** of P for the previous call on the same [database connection] D,
4935** or NULL for the first call.
4936**
4937** {H12975} If the update hook callback F in [sqlite3_update_hook(D,F,P)]
4938** is NULL then the no update callbacks are made.
4939**
4940** {H12977} Each call to [sqlite3_update_hook(D,F,P)] overrides prior calls
4941** to the same interface on the same [database connection] D.
4942**
4943** {H12979} The update hook callback is not invoked when internal system
4944** tables such as sqlite_master and sqlite_sequence are modified.
4945**
4946** {H12981} The second parameter to the update callback
4947** is one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE],
4948** depending on the operation that caused the callback to be invoked.
4949**
4950** {H12983} The third and fourth arguments to the callback contain pointers
4951** to zero-terminated UTF-8 strings which are the names of the
4952** database and table that is being updated.
4953
4954** {H12985} The final callback parameter is the rowid of the row after
4955** the change occurs.
4956*/
4957void *sqlite3_update_hook(
4958 sqlite3*,
4959 void(*)(void *,int ,char const *,char const *,sqlite3_int64),
4960 void*
4961);
4962
4963/*
4964** CAPI3REF: Enable Or Disable Shared Pager Cache {H10330} <S30900>
4965** KEYWORDS: {shared cache} {shared cache mode}
4966**
4967** This routine enables or disables the sharing of the database cache
4968** and schema data structures between [database connection | connections]
4969** to the same database. Sharing is enabled if the argument is true
4970** and disabled if the argument is false.
4971**
4972** Cache sharing is enabled and disabled for an entire process. {END}
4973** This is a change as of SQLite version 3.5.0. In prior versions of SQLite,
4974** sharing was enabled or disabled for each thread separately.
4975**
4976** The cache sharing mode set by this interface effects all subsequent
4977** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
4978** Existing database connections continue use the sharing mode
4979** that was in effect at the time they were opened.
4980**
4981** Virtual tables cannot be used with a shared cache. When shared
4982** cache is enabled, the [sqlite3_create_module()] API used to register
4983** virtual tables will always return an error.
4984**
4985** This routine returns [SQLITE_OK] if shared cache was enabled or disabled
4986** successfully. An [error code] is returned otherwise.
4987**
4988** Shared cache is disabled by default. But this might change in
4989** future releases of SQLite. Applications that care about shared
4990** cache setting should set it explicitly.
4991**
4992** INVARIANTS:
4993**
4994** {H10331} A successful invocation of [sqlite3_enable_shared_cache(B)]
4995** will enable or disable shared cache mode for any subsequently
4996** created [database connection] in the same process.
4997**
4998** {H10336} When shared cache is enabled, the [sqlite3_create_module()]
4999** interface will always return an error.
5000**
5001** {H10337} The [sqlite3_enable_shared_cache(B)] interface returns
5002** [SQLITE_OK] if shared cache was enabled or disabled successfully.
5003**
5004** {H10339} Shared cache is disabled by default.
5005*/
5006int sqlite3_enable_shared_cache(int);
5007
5008/*
5009** CAPI3REF: Attempt To Free Heap Memory {H17340} <S30220>
5010**
5011** The sqlite3_release_memory() interface attempts to free N bytes
5012** of heap memory by deallocating non-essential memory allocations
5013** held by the database library. {END} Memory used to cache database
5014** pages to improve performance is an example of non-essential memory.
5015** sqlite3_release_memory() returns the number of bytes actually freed,
5016** which might be more or less than the amount requested.
5017**
5018** INVARIANTS:
5019**
5020** {H17341} The [sqlite3_release_memory(N)] interface attempts to
5021** free N bytes of heap memory by deallocating non-essential
5022** memory allocations held by the database library.
5023**
5024** {H16342} The [sqlite3_release_memory(N)] returns the number
5025** of bytes actually freed, which might be more or less
5026** than the amount requested.
5027*/
5028int sqlite3_release_memory(int);
5029
5030/*
5031** CAPI3REF: Impose A Limit On Heap Size {H17350} <S30220>
5032**
5033** The sqlite3_soft_heap_limit() interface places a "soft" limit
5034** on the amount of heap memory that may be allocated by SQLite.
5035** If an internal allocation is requested that would exceed the
5036** soft heap limit, [sqlite3_release_memory()] is invoked one or
5037** more times to free up some space before the allocation is performed.
5038**
5039** The limit is called "soft", because if [sqlite3_release_memory()]
5040** cannot free sufficient memory to prevent the limit from being exceeded,
5041** the memory is allocated anyway and the current operation proceeds.
5042**
5043** A negative or zero value for N means that there is no soft heap limit and
5044** [sqlite3_release_memory()] will only be called when memory is exhausted.
5045** The default value for the soft heap limit is zero.
5046**
5047** SQLite makes a best effort to honor the soft heap limit.
5048** But if the soft heap limit cannot be honored, execution will
5049** continue without error or notification. This is why the limit is
5050** called a "soft" limit. It is advisory only.
5051**
5052** Prior to SQLite version 3.5.0, this routine only constrained the memory
5053** allocated by a single thread - the same thread in which this routine
5054** runs. Beginning with SQLite version 3.5.0, the soft heap limit is
5055** applied to all threads. The value specified for the soft heap limit
5056** is an upper bound on the total memory allocation for all threads. In
5057** version 3.5.0 there is no mechanism for limiting the heap usage for
5058** individual threads.
5059**
5060** INVARIANTS:
5061**
5062** {H16351} The [sqlite3_soft_heap_limit(N)] interface places a soft limit
5063** of N bytes on the amount of heap memory that may be allocated
5064** using [sqlite3_malloc()] or [sqlite3_realloc()] at any point
5065** in time.
5066**
5067** {H16352} If a call to [sqlite3_malloc()] or [sqlite3_realloc()] would
5068** cause the total amount of allocated memory to exceed the
5069** soft heap limit, then [sqlite3_release_memory()] is invoked
5070** in an attempt to reduce the memory usage prior to proceeding
5071** with the memory allocation attempt.
5072**
5073** {H16353} Calls to [sqlite3_malloc()] or [sqlite3_realloc()] that trigger
5074** attempts to reduce memory usage through the soft heap limit
5075** mechanism continue even if the attempt to reduce memory
5076** usage is unsuccessful.
5077**
5078** {H16354} A negative or zero value for N in a call to
5079** [sqlite3_soft_heap_limit(N)] means that there is no soft
5080** heap limit and [sqlite3_release_memory()] will only be
5081** called when memory is completely exhausted.
5082**
5083** {H16355} The default value for the soft heap limit is zero.
5084**
5085** {H16358} Each call to [sqlite3_soft_heap_limit(N)] overrides the
5086** values set by all prior calls.
5087*/
5088void sqlite3_soft_heap_limit(int);
5089
5090/*
5091** CAPI3REF: Extract Metadata About A Column Of A Table {H12850} <S60300>
5092**
5093** This routine returns metadata about a specific column of a specific
5094** database table accessible using the [database connection] handle
5095** passed as the first function argument.
5096**
5097** The column is identified by the second, third and fourth parameters to
5098** this function. The second parameter is either the name of the database
5099** (i.e. "main", "temp" or an attached database) containing the specified
5100** table or NULL. If it is NULL, then all attached databases are searched
5101** for the table using the same algorithm used by the database engine to
5102** resolve unqualified table references.
5103**
5104** The third and fourth parameters to this function are the table and column
5105** name of the desired column, respectively. Neither of these parameters
5106** may be NULL.
5107**
5108** Metadata is returned by writing to the memory locations passed as the 5th
5109** and subsequent parameters to this function. Any of these arguments may be
5110** NULL, in which case the corresponding element of metadata is omitted.
5111**
5112** <blockquote>
5113** <table border="1">
5114** <tr><th> Parameter <th> Output<br>Type <th> Description
5115**
5116** <tr><td> 5th <td> const char* <td> Data type
5117** <tr><td> 6th <td> const char* <td> Name of default collation sequence
5118** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint
5119** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY
5120** <tr><td> 9th <td> int <td> True if column is AUTOINCREMENT
5121** </table>
5122** </blockquote>
5123**
5124** The memory pointed to by the character pointers returned for the
5125** declaration type and collation sequence is valid only until the next
5126** call to any SQLite API function.
5127**
5128** If the specified table is actually a view, an [error code] is returned.
5129**
5130** If the specified column is "rowid", "oid" or "_rowid_" and an
5131** INTEGER PRIMARY KEY column has been explicitly declared, then the output
5132** parameters are set for the explicitly declared column. If there is no
5133** explicitly declared INTEGER PRIMARY KEY column, then the output
5134** parameters are set as follows:
5135**
5136** <pre>
5137** data type: "INTEGER"
5138** collation sequence: "BINARY"
5139** not null: 0
5140** primary key: 1
5141** auto increment: 0
5142** </pre>
5143**
5144** This function may load one or more schemas from database files. If an
5145** error occurs during this process, or if the requested table or column
5146** cannot be found, an [error code] is returned and an error message left
5147** in the [database connection] (to be retrieved using sqlite3_errmsg()).
5148**
5149** This API is only available if the library was compiled with the
5150** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined.
5151*/
5152int sqlite3_table_column_metadata(
5153 sqlite3 *db, /* Connection handle */
5154 const char *zDbName, /* Database name or NULL */
5155 const char *zTableName, /* Table name */
5156 const char *zColumnName, /* Column name */
5157 char const **pzDataType, /* OUTPUT: Declared data type */
5158 char const **pzCollSeq, /* OUTPUT: Collation sequence name */
5159 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */
5160 int *pPrimaryKey, /* OUTPUT: True if column part of PK */
5161 int *pAutoinc /* OUTPUT: True if column is auto-increment */
5162);
5163
5164/*
5165** CAPI3REF: Load An Extension {H12600} <S20500>
5166**
5167** This interface loads an SQLite extension library from the named file.
5168**
5169** {H12601} The sqlite3_load_extension() interface attempts to load an
5170** SQLite extension library contained in the file zFile.
5171**
5172** {H12602} The entry point is zProc.
5173**
5174** {H12603} zProc may be 0, in which case the name of the entry point
5175** defaults to "sqlite3_extension_init".
5176**
5177** {H12604} The sqlite3_load_extension() interface shall return
5178** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
5179**
5180** {H12605} If an error occurs and pzErrMsg is not 0, then the
5181** [sqlite3_load_extension()] interface shall attempt to
5182** fill *pzErrMsg with error message text stored in memory
5183** obtained from [sqlite3_malloc()]. {END} The calling function
5184** should free this memory by calling [sqlite3_free()].
5185**
5186** {H12606} Extension loading must be enabled using
5187** [sqlite3_enable_load_extension()] prior to calling this API,
5188** otherwise an error will be returned.
5189*/
5190int sqlite3_load_extension(
5191 sqlite3 *db, /* Load the extension into this database connection */
5192 const char *zFile, /* Name of the shared library containing extension */
5193 const char *zProc, /* Entry point. Derived from zFile if 0 */
5194 char **pzErrMsg /* Put error message here if not 0 */
5195);
5196
5197/*
5198** CAPI3REF: Enable Or Disable Extension Loading {H12620} <S20500>
5199**
5200** So as not to open security holes in older applications that are
5201** unprepared to deal with extension loading, and as a means of disabling
5202** extension loading while evaluating user-entered SQL, the following API
5203** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
5204**
5205** Extension loading is off by default. See ticket #1863.
5206**
5207** {H12621} Call the sqlite3_enable_load_extension() routine with onoff==1
5208** to turn extension loading on and call it with onoff==0 to turn
5209** it back off again.
5210**
5211** {H12622} Extension loading is off by default.
5212*/
5213int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
5214
5215/*
5216** CAPI3REF: Automatically Load An Extensions {H12640} <S20500>
5217**
5218** This API can be invoked at program startup in order to register
5219** one or more statically linked extensions that will be available
5220** to all new [database connections]. {END}
5221**
5222** This routine stores a pointer to the extension in an array that is
5223** obtained from [sqlite3_malloc()]. If you run a memory leak checker
5224** on your program and it reports a leak because of this array, invoke
5225** [sqlite3_reset_auto_extension()] prior to shutdown to free the memory.
5226**
5227** {H12641} This function registers an extension entry point that is
5228** automatically invoked whenever a new [database connection]
5229** is opened using [sqlite3_open()], [sqlite3_open16()],
5230** or [sqlite3_open_v2()].
5231**
5232** {H12642} Duplicate extensions are detected so calling this routine
5233** multiple times with the same extension is harmless.
5234**
5235** {H12643} This routine stores a pointer to the extension in an array
5236** that is obtained from [sqlite3_malloc()].
5237**
5238** {H12644} Automatic extensions apply across all threads.
5239*/
5240int sqlite3_auto_extension(void *xEntryPoint);
5241
5242/*
5243** CAPI3REF: Reset Automatic Extension Loading {H12660} <S20500>
5244**
5245** This function disables all previously registered automatic
5246** extensions. {END} It undoes the effect of all prior
5247** [sqlite3_auto_extension()] calls.
5248**
5249** {H12661} This function disables all previously registered
5250** automatic extensions.
5251**
5252** {H12662} This function disables automatic extensions in all threads.
5253*/
5254void sqlite3_reset_auto_extension(void);
5255
5256/*
5257****** EXPERIMENTAL - subject to change without notice **************
5258**
5259** The interface to the virtual-table mechanism is currently considered
5260** to be experimental. The interface might change in incompatible ways.
5261** If this is a problem for you, do not use the interface at this time.
5262**
5263** When the virtual-table mechanism stabilizes, we will declare the
5264** interface fixed, support it indefinitely, and remove this comment.
5265*/
5266
5267/*
5268** Structures used by the virtual table interface
5269*/
5270typedef struct sqlite3_vtab sqlite3_vtab;
5271typedef struct sqlite3_index_info sqlite3_index_info;
5272typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
5273typedef struct sqlite3_module sqlite3_module;
5274
5275/*
5276** CAPI3REF: Virtual Table Object {H18000} <S20400>
5277** KEYWORDS: sqlite3_module
5278** EXPERIMENTAL
5279**
5280** A module is a class of virtual tables. Each module is defined
5281** by an instance of the following structure. This structure consists
5282** mostly of methods for the module.
5283**
5284** This interface is experimental and is subject to change or
5285** removal in future releases of SQLite.
5286*/
5287struct sqlite3_module {
5288 int iVersion;
5289 int (*xCreate)(sqlite3*, void *pAux,
5290 int argc, const char *const*argv,
5291 sqlite3_vtab **ppVTab, char**);
5292 int (*xConnect)(sqlite3*, void *pAux,
5293 int argc, const char *const*argv,
5294 sqlite3_vtab **ppVTab, char**);
5295 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
5296 int (*xDisconnect)(sqlite3_vtab *pVTab);
5297 int (*xDestroy)(sqlite3_vtab *pVTab);
5298 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
5299 int (*xClose)(sqlite3_vtab_cursor*);
5300 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
5301 int argc, sqlite3_value **argv);
5302 int (*xNext)(sqlite3_vtab_cursor*);
5303 int (*xEof)(sqlite3_vtab_cursor*);
5304 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
5305 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
5306 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
5307 int (*xBegin)(sqlite3_vtab *pVTab);
5308 int (*xSync)(sqlite3_vtab *pVTab);
5309 int (*xCommit)(sqlite3_vtab *pVTab);
5310 int (*xRollback)(sqlite3_vtab *pVTab);
5311 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
5312 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
5313 void **ppArg);
5314 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
5315};
5316
5317/*
5318** CAPI3REF: Virtual Table Indexing Information {H18100} <S20400>
5319** KEYWORDS: sqlite3_index_info
5320** EXPERIMENTAL
5321**
5322** The sqlite3_index_info structure and its substructures is used to
5323** pass information into and receive the reply from the xBestIndex
5324** method of an sqlite3_module. The fields under **Inputs** are the
5325** inputs to xBestIndex and are read-only. xBestIndex inserts its
5326** results into the **Outputs** fields.
5327**
5328** The aConstraint[] array records WHERE clause constraints of the form:
5329**
5330** <pre>column OP expr</pre>
5331**
5332** where OP is =, &lt;, &lt;=, &gt;, or &gt;=. The particular operator is
5333** stored in aConstraint[].op. The index of the column is stored in
5334** aConstraint[].iColumn. aConstraint[].usable is TRUE if the
5335** expr on the right-hand side can be evaluated (and thus the constraint
5336** is usable) and false if it cannot.
5337**
5338** The optimizer automatically inverts terms of the form "expr OP column"
5339** and makes other simplifications to the WHERE clause in an attempt to
5340** get as many WHERE clause terms into the form shown above as possible.
5341** The aConstraint[] array only reports WHERE clause terms in the correct
5342** form that refer to the particular virtual table being queried.
5343**
5344** Information about the ORDER BY clause is stored in aOrderBy[].
5345** Each term of aOrderBy records a column of the ORDER BY clause.
5346**
5347** The xBestIndex method must fill aConstraintUsage[] with information
5348** about what parameters to pass to xFilter. If argvIndex>0 then
5349** the right-hand side of the corresponding aConstraint[] is evaluated
5350** and becomes the argvIndex-th entry in argv. If aConstraintUsage[].omit
5351** is true, then the constraint is assumed to be fully handled by the
5352** virtual table and is not checked again by SQLite.
5353**
5354** The idxNum and idxPtr values are recorded and passed into xFilter.
5355** sqlite3_free() is used to free idxPtr if needToFreeIdxPtr is true.
5356**
5357** The orderByConsumed means that output from xFilter will occur in
5358** the correct order to satisfy the ORDER BY clause so that no separate
5359** sorting step is required.
5360**
5361** The estimatedCost value is an estimate of the cost of doing the
5362** particular lookup. A full scan of a table with N entries should have
5363** a cost of N. A binary search of a table of N entries should have a
5364** cost of approximately log(N).
5365**
5366** This interface is experimental and is subject to change or
5367** removal in future releases of SQLite.
5368*/
5369struct sqlite3_index_info {
5370 /* Inputs */
5371 int nConstraint; /* Number of entries in aConstraint */
5372 struct sqlite3_index_constraint {
5373 int iColumn; /* Column on left-hand side of constraint */
5374 unsigned char op; /* Constraint operator */
5375 unsigned char usable; /* True if this constraint is usable */
5376 int iTermOffset; /* Used internally - xBestIndex should ignore */
5377 } *aConstraint; /* Table of WHERE clause constraints */
5378 int nOrderBy; /* Number of terms in the ORDER BY clause */
5379 struct sqlite3_index_orderby {
5380 int iColumn; /* Column number */
5381 unsigned char desc; /* True for DESC. False for ASC. */
5382 } *aOrderBy; /* The ORDER BY clause */
5383 /* Outputs */
5384 struct sqlite3_index_constraint_usage {
5385 int argvIndex; /* if >0, constraint is part of argv to xFilter */
5386 unsigned char omit; /* Do not code a test for this constraint */
5387 } *aConstraintUsage;
5388 int idxNum; /* Number used to identify the index */
5389 char *idxStr; /* String, possibly obtained from sqlite3_malloc */
5390 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */
5391 int orderByConsumed; /* True if output is already ordered */
5392 double estimatedCost; /* Estimated cost of using this index */
5393};
5394#define SQLITE_INDEX_CONSTRAINT_EQ 2
5395#define SQLITE_INDEX_CONSTRAINT_GT 4
5396#define SQLITE_INDEX_CONSTRAINT_LE 8
5397#define SQLITE_INDEX_CONSTRAINT_LT 16
5398#define SQLITE_INDEX_CONSTRAINT_GE 32
5399#define SQLITE_INDEX_CONSTRAINT_MATCH 64
5400
5401/*
5402** CAPI3REF: Register A Virtual Table Implementation {H18200} <S20400>
5403** EXPERIMENTAL
5404**
5405** This routine is used to register a new module name with a
5406** [database connection]. Module names must be registered before
5407** creating new virtual tables on the module, or before using
5408** preexisting virtual tables of the module.
5409**
5410** This interface is experimental and is subject to change or
5411** removal in future releases of SQLite.
5412*/
5413SQLITE_EXPERIMENTAL int sqlite3_create_module(
5414 sqlite3 *db, /* SQLite connection to register module with */
5415 const char *zName, /* Name of the module */
5416 const sqlite3_module *, /* Methods for the module */
5417 void * /* Client data for xCreate/xConnect */
5418);
5419
5420/*
5421** CAPI3REF: Register A Virtual Table Implementation {H18210} <S20400>
5422** EXPERIMENTAL
5423**
5424** This routine is identical to the [sqlite3_create_module()] method above,
5425** except that it allows a destructor function to be specified. It is
5426** even more experimental than the rest of the virtual tables API.
5427*/
5428SQLITE_EXPERIMENTAL int sqlite3_create_module_v2(
5429 sqlite3 *db, /* SQLite connection to register module with */
5430 const char *zName, /* Name of the module */
5431 const sqlite3_module *, /* Methods for the module */
5432 void *, /* Client data for xCreate/xConnect */
5433 void(*xDestroy)(void*) /* Module destructor function */
5434);
5435
5436/*
5437** CAPI3REF: Virtual Table Instance Object {H18010} <S20400>
5438** KEYWORDS: sqlite3_vtab
5439** EXPERIMENTAL
5440**
5441** Every module implementation uses a subclass of the following structure
5442** to describe a particular instance of the module. Each subclass will
5443** be tailored to the specific needs of the module implementation.
5444** The purpose of this superclass is to define certain fields that are
5445** common to all module implementations.
5446**
5447** Virtual tables methods can set an error message by assigning a
5448** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should
5449** take care that any prior string is freed by a call to [sqlite3_free()]
5450** prior to assigning a new string to zErrMsg. After the error message
5451** is delivered up to the client application, the string will be automatically
5452** freed by sqlite3_free() and the zErrMsg field will be zeroed. Note
5453** that sqlite3_mprintf() and sqlite3_free() are used on the zErrMsg field
5454** since virtual tables are commonly implemented in loadable extensions which
5455** do not have access to sqlite3MPrintf() or sqlite3Free().
5456**
5457** This interface is experimental and is subject to change or
5458** removal in future releases of SQLite.
5459*/
5460struct sqlite3_vtab {
5461 const sqlite3_module *pModule; /* The module for this virtual table */
5462 int nRef; /* Used internally */
5463 char *zErrMsg; /* Error message from sqlite3_mprintf() */
5464 /* Virtual table implementations will typically add additional fields */
5465};
5466
5467/*
5468** CAPI3REF: Virtual Table Cursor Object {H18020} <S20400>
5469** KEYWORDS: sqlite3_vtab_cursor
5470** EXPERIMENTAL
5471**
5472** Every module implementation uses a subclass of the following structure
5473** to describe cursors that point into the virtual table and are used
5474** to loop through the virtual table. Cursors are created using the
5475** xOpen method of the module. Each module implementation will define
5476** the content of a cursor structure to suit its own needs.
5477**
5478** This superclass exists in order to define fields of the cursor that
5479** are common to all implementations.
5480**
5481** This interface is experimental and is subject to change or
5482** removal in future releases of SQLite.
5483*/
5484struct sqlite3_vtab_cursor {
5485 sqlite3_vtab *pVtab; /* Virtual table of this cursor */
5486 /* Virtual table implementations will typically add additional fields */
5487};
5488
5489/*
5490** CAPI3REF: Declare The Schema Of A Virtual Table {H18280} <S20400>
5491** EXPERIMENTAL
5492**
5493** The xCreate and xConnect methods of a module use the following API
5494** to declare the format (the names and datatypes of the columns) of
5495** the virtual tables they implement.
5496**
5497** This interface is experimental and is subject to change or
5498** removal in future releases of SQLite.
5499*/
5500SQLITE_EXPERIMENTAL int sqlite3_declare_vtab(sqlite3*, const char *zCreateTable);
5501
5502/*
5503** CAPI3REF: Overload A Function For A Virtual Table {H18300} <S20400>
5504** EXPERIMENTAL
5505**
5506** Virtual tables can provide alternative implementations of functions
5507** using the xFindFunction method. But global versions of those functions
5508** must exist in order to be overloaded.
5509**
5510** This API makes sure a global version of a function with a particular
5511** name and number of parameters exists. If no such function exists
5512** before this API is called, a new function is created. The implementation
5513** of the new function always causes an exception to be thrown. So
5514** the new function is not good for anything by itself. Its only
5515** purpose is to be a placeholder function that can be overloaded
5516** by virtual tables.
5517**
5518** This API should be considered part of the virtual table interface,
5519** which is experimental and subject to change.
5520*/
5521SQLITE_EXPERIMENTAL int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
5522
5523/*
5524** The interface to the virtual-table mechanism defined above (back up
5525** to a comment remarkably similar to this one) is currently considered
5526** to be experimental. The interface might change in incompatible ways.
5527** If this is a problem for you, do not use the interface at this time.
5528**
5529** When the virtual-table mechanism stabilizes, we will declare the
5530** interface fixed, support it indefinitely, and remove this comment.
5531**
5532****** EXPERIMENTAL - subject to change without notice **************
5533*/
5534
5535/*
5536** CAPI3REF: A Handle To An Open BLOB {H17800} <S30230>
5537** KEYWORDS: {BLOB handle} {BLOB handles}
5538**
5539** An instance of this object represents an open BLOB on which
5540** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
5541** Objects of this type are created by [sqlite3_blob_open()]
5542** and destroyed by [sqlite3_blob_close()].
5543** The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
5544** can be used to read or write small subsections of the BLOB.
5545** The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
5546*/
5547typedef struct sqlite3_blob sqlite3_blob;
5548
5549/*
5550** CAPI3REF: Open A BLOB For Incremental I/O {H17810} <S30230>
5551**
5552** This interfaces opens a [BLOB handle | handle] to the BLOB located
5553** in row iRow, column zColumn, table zTable in database zDb;
5554** in other words, the same BLOB that would be selected by:
5555**
5556** <pre>
5557** SELECT zColumn FROM zDb.zTable WHERE rowid = iRow;
5558** </pre> {END}
5559**
5560** If the flags parameter is non-zero, the the BLOB is opened for read
5561** and write access. If it is zero, the BLOB is opened for read access.
5562**
5563** Note that the database name is not the filename that contains
5564** the database but rather the symbolic name of the database that
5565** is assigned when the database is connected using [ATTACH].
5566** For the main database file, the database name is "main".
5567** For TEMP tables, the database name is "temp".
5568**
5569** On success, [SQLITE_OK] is returned and the new [BLOB handle] is written
5570** to *ppBlob. Otherwise an [error code] is returned and any value written
5571** to *ppBlob should not be used by the caller.
5572** This function sets the [database connection] error code and message
5573** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()].
5574**
5575** If the row that a BLOB handle points to is modified by an
5576** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
5577** then the BLOB handle is marked as "expired".
5578** This is true if any column of the row is changed, even a column
5579** other than the one the BLOB handle is open on.
5580** Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
5581** a expired BLOB handle fail with an return code of [SQLITE_ABORT].
5582** Changes written into a BLOB prior to the BLOB expiring are not
5583** rollback by the expiration of the BLOB. Such changes will eventually
5584** commit if the transaction continues to completion.
5585**
5586** INVARIANTS:
5587**
5588** {H17813} A successful invocation of the [sqlite3_blob_open(D,B,T,C,R,F,P)]
5589** interface shall open an [sqlite3_blob] object P on the BLOB
5590** in column C of the table T in the database B on
5591** the [database connection] D.
5592**
5593** {H17814} A successful invocation of [sqlite3_blob_open(D,...)] shall start
5594** a new transaction on the [database connection] D if that
5595** connection is not already in a transaction.
5596**
5597** {H17816} The [sqlite3_blob_open(D,B,T,C,R,F,P)] interface shall open
5598** the BLOB for read and write access if and only if the F
5599** parameter is non-zero.
5600**
5601** {H17819} The [sqlite3_blob_open()] interface shall return [SQLITE_OK] on
5602** success and an appropriate [error code] on failure.
5603**
5604** {H17821} If an error occurs during evaluation of [sqlite3_blob_open(D,...)]
5605** then subsequent calls to [sqlite3_errcode(D)],
5606** [sqlite3_errmsg(D)], and [sqlite3_errmsg16(D)] shall return
5607** information appropriate for that error.
5608**
5609** {H17824} If any column in the row that a [sqlite3_blob] has open is
5610** changed by a separate [UPDATE] or [DELETE] statement or by
5611** an [ON CONFLICT] side effect, then the [sqlite3_blob] shall
5612** be marked as invalid.
5613*/
5614int sqlite3_blob_open(
5615 sqlite3*,
5616 const char *zDb,
5617 const char *zTable,
5618 const char *zColumn,
5619 sqlite3_int64 iRow,
5620 int flags,
5621 sqlite3_blob **ppBlob
5622);
5623
5624/*
5625** CAPI3REF: Close A BLOB Handle {H17830} <S30230>
5626**
5627** Closes an open [BLOB handle].
5628**
5629** Closing a BLOB shall cause the current transaction to commit
5630** if there are no other BLOBs, no pending prepared statements, and the
5631** database connection is in [autocommit mode].
5632** If any writes were made to the BLOB, they might be held in cache
5633** until the close operation if they will fit. {END}
5634**
5635** Closing the BLOB often forces the changes
5636** out to disk and so if any I/O errors occur, they will likely occur
5637** at the time when the BLOB is closed. {H17833} Any errors that occur during
5638** closing are reported as a non-zero return value.
5639**
5640** The BLOB is closed unconditionally. Even if this routine returns
5641** an error code, the BLOB is still closed.
5642**
5643** INVARIANTS:
5644**
5645** {H17833} The [sqlite3_blob_close(P)] interface closes an [sqlite3_blob]
5646** object P previously opened using [sqlite3_blob_open()].
5647**
5648** {H17836} Closing an [sqlite3_blob] object using
5649** [sqlite3_blob_close()] shall cause the current transaction to
5650** commit if there are no other open [sqlite3_blob] objects
5651** or [prepared statements] on the same [database connection] and
5652** the database connection is in [autocommit mode].
5653**
5654** {H17839} The [sqlite3_blob_close(P)] interfaces shall close the
5655** [sqlite3_blob] object P unconditionally, even if
5656** [sqlite3_blob_close(P)] returns something other than [SQLITE_OK].
5657*/
5658int sqlite3_blob_close(sqlite3_blob *);
5659
5660/*
5661** CAPI3REF: Return The Size Of An Open BLOB {H17840} <S30230>
5662**
5663** Returns the size in bytes of the BLOB accessible via the open
5664** []BLOB handle] in its only argument.
5665**
5666** INVARIANTS:
5667**
5668** {H17843} The [sqlite3_blob_bytes(P)] interface returns the size
5669** in bytes of the BLOB that the [sqlite3_blob] object P
5670** refers to.
5671*/
5672int sqlite3_blob_bytes(sqlite3_blob *);
5673
5674/*
5675** CAPI3REF: Read Data From A BLOB Incrementally {H17850} <S30230>
5676**
5677** This function is used to read data from an open [BLOB handle] into a
5678** caller-supplied buffer. N bytes of data are copied into buffer Z
5679** from the open BLOB, starting at offset iOffset.
5680**
5681** If offset iOffset is less than N bytes from the end of the BLOB,
5682** [SQLITE_ERROR] is returned and no data is read. If N or iOffset is
5683** less than zero, [SQLITE_ERROR] is returned and no data is read.
5684**
5685** An attempt to read from an expired [BLOB handle] fails with an
5686** error code of [SQLITE_ABORT].
5687**
5688** On success, SQLITE_OK is returned.
5689** Otherwise, an [error code] or an [extended error code] is returned.
5690**
5691** INVARIANTS:
5692**
5693** {H17853} A successful invocation of [sqlite3_blob_read(P,Z,N,X)]
5694** shall reads N bytes of data out of the BLOB referenced by
5695** [BLOB handle] P beginning at offset X and store those bytes
5696** into buffer Z.
5697**
5698** {H17856} In [sqlite3_blob_read(P,Z,N,X)] if the size of the BLOB
5699** is less than N+X bytes, then the function shall leave the
5700** Z buffer unchanged and return [SQLITE_ERROR].
5701**
5702** {H17859} In [sqlite3_blob_read(P,Z,N,X)] if X or N is less than zero
5703** then the function shall leave the Z buffer unchanged
5704** and return [SQLITE_ERROR].
5705**
5706** {H17862} The [sqlite3_blob_read(P,Z,N,X)] interface shall return [SQLITE_OK]
5707** if N bytes are successfully read into buffer Z.
5708**
5709** {H17863} If the [BLOB handle] P is expired and X and N are within bounds
5710** then [sqlite3_blob_read(P,Z,N,X)] shall leave the Z buffer
5711** unchanged and return [SQLITE_ABORT].
5712**
5713** {H17865} If the requested read could not be completed,
5714** the [sqlite3_blob_read(P,Z,N,X)] interface shall return an
5715** appropriate [error code] or [extended error code].
5716**
5717** {H17868} If an error occurs during evaluation of [sqlite3_blob_read(P,...)]
5718** then subsequent calls to [sqlite3_errcode(D)],
5719** [sqlite3_errmsg(D)], and [sqlite3_errmsg16(D)] shall return
5720** information appropriate for that error, where D is the
5721** [database connection] that was used to open the [BLOB handle] P.
5722*/
5723int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
5724
5725/*
5726** CAPI3REF: Write Data Into A BLOB Incrementally {H17870} <S30230>
5727**
5728** This function is used to write data into an open [BLOB handle] from a
5729** caller-supplied buffer. N bytes of data are copied from the buffer Z
5730** into the open BLOB, starting at offset iOffset.
5731**
5732** If the [BLOB handle] passed as the first argument was not opened for
5733** writing (the flags parameter to [sqlite3_blob_open()] was zero),
5734** this function returns [SQLITE_READONLY].
5735**
5736** This function may only modify the contents of the BLOB; it is
5737** not possible to increase the size of a BLOB using this API.
5738** If offset iOffset is less than N bytes from the end of the BLOB,
5739** [SQLITE_ERROR] is returned and no data is written. If N is
5740** less than zero [SQLITE_ERROR] is returned and no data is written.
5741**
5742** An attempt to write to an expired [BLOB handle] fails with an
5743** error code of [SQLITE_ABORT]. Writes to the BLOB that occurred
5744** before the [BLOB handle] expired are not rolled back by the
5745** expiration of the handle, though of course those changes might
5746** have been overwritten by the statement that expired the BLOB handle
5747** or by other independent statements.
5748**
5749** On success, SQLITE_OK is returned.
5750** Otherwise, an [error code] or an [extended error code] is returned.
5751**
5752** INVARIANTS:
5753**
5754** {H17873} A successful invocation of [sqlite3_blob_write(P,Z,N,X)]
5755** shall write N bytes of data from buffer Z into the BLOB
5756** referenced by [BLOB handle] P beginning at offset X into
5757** the BLOB.
5758**
5759** {H17874} In the absence of other overridding changes, the changes
5760** written to a BLOB by [sqlite3_blob_write()] shall
5761** remain in effect after the associated [BLOB handle] expires.
5762**
5763** {H17875} If the [BLOB handle] P was opened for reading only then
5764** an invocation of [sqlite3_blob_write(P,Z,N,X)] shall leave
5765** the referenced BLOB unchanged and return [SQLITE_READONLY].
5766**
5767** {H17876} If the size of the BLOB referenced by [BLOB handle] P is
5768** less than N+X bytes then [sqlite3_blob_write(P,Z,N,X)] shall
5769** leave the BLOB unchanged and return [SQLITE_ERROR].
5770**
5771** {H17877} If the [BLOB handle] P is expired and X and N are within bounds
5772** then [sqlite3_blob_read(P,Z,N,X)] shall leave the BLOB
5773** unchanged and return [SQLITE_ABORT].
5774**
5775** {H17879} If X or N are less than zero then [sqlite3_blob_write(P,Z,N,X)]
5776** shall leave the BLOB referenced by [BLOB handle] P unchanged
5777** and return [SQLITE_ERROR].
5778**
5779** {H17882} The [sqlite3_blob_write(P,Z,N,X)] interface shall return
5780** [SQLITE_OK] if N bytes where successfully written into the BLOB.
5781**
5782** {H17885} If the requested write could not be completed,
5783** the [sqlite3_blob_write(P,Z,N,X)] interface shall return an
5784** appropriate [error code] or [extended error code].
5785**
5786** {H17888} If an error occurs during evaluation of [sqlite3_blob_write(D,...)]
5787** then subsequent calls to [sqlite3_errcode(D)],
5788** [sqlite3_errmsg(D)], and [sqlite3_errmsg16(D)] shall return
5789** information appropriate for that error.
5790*/
5791int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
5792
5793/*
5794** CAPI3REF: Virtual File System Objects {H11200} <S20100>
5795**
5796** A virtual filesystem (VFS) is an [sqlite3_vfs] object
5797** that SQLite uses to interact
5798** with the underlying operating system. Most SQLite builds come with a
5799** single default VFS that is appropriate for the host computer.
5800** New VFSes can be registered and existing VFSes can be unregistered.
5801** The following interfaces are provided.
5802**
5803** The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
5804** Names are case sensitive.
5805** Names are zero-terminated UTF-8 strings.
5806** If there is no match, a NULL pointer is returned.
5807** If zVfsName is NULL then the default VFS is returned.
5808**
5809** New VFSes are registered with sqlite3_vfs_register().
5810** Each new VFS becomes the default VFS if the makeDflt flag is set.
5811** The same VFS can be registered multiple times without injury.
5812** To make an existing VFS into the default VFS, register it again
5813** with the makeDflt flag set. If two different VFSes with the
5814** same name are registered, the behavior is undefined. If a
5815** VFS is registered with a name that is NULL or an empty string,
5816** then the behavior is undefined.
5817**
5818** Unregister a VFS with the sqlite3_vfs_unregister() interface.
5819** If the default VFS is unregistered, another VFS is chosen as
5820** the default. The choice for the new VFS is arbitrary.
5821**
5822** INVARIANTS:
5823**
5824** {H11203} The [sqlite3_vfs_find(N)] interface returns a pointer to the
5825** registered [sqlite3_vfs] object whose name exactly matches
5826** the zero-terminated UTF-8 string N, or it returns NULL if
5827** there is no match.
5828**
5829** {H11206} If the N parameter to [sqlite3_vfs_find(N)] is NULL then
5830** the function returns a pointer to the default [sqlite3_vfs]
5831** object if there is one, or NULL if there is no default
5832** [sqlite3_vfs] object.
5833**
5834** {H11209} The [sqlite3_vfs_register(P,F)] interface registers the
5835** well-formed [sqlite3_vfs] object P using the name given
5836** by the zName field of the object.
5837**
5838** {H11212} Using the [sqlite3_vfs_register(P,F)] interface to register
5839** the same [sqlite3_vfs] object multiple times is a harmless no-op.
5840**
5841** {H11215} The [sqlite3_vfs_register(P,F)] interface makes the [sqlite3_vfs]
5842** object P the default [sqlite3_vfs] object if F is non-zero.
5843**
5844** {H11218} The [sqlite3_vfs_unregister(P)] interface unregisters the
5845** [sqlite3_vfs] object P so that it is no longer returned by
5846** subsequent calls to [sqlite3_vfs_find()].
5847*/
5848sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
5849int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
5850int sqlite3_vfs_unregister(sqlite3_vfs*);
5851
5852/*
5853** CAPI3REF: Mutexes {H17000} <S20000>
5854**
5855** The SQLite core uses these routines for thread
5856** synchronization. Though they are intended for internal
5857** use by SQLite, code that links against SQLite is
5858** permitted to use any of these routines.
5859**
5860** The SQLite source code contains multiple implementations
5861** of these mutex routines. An appropriate implementation
5862** is selected automatically at compile-time. The following
5863** implementations are available in the SQLite core:
5864**
5865** <ul>
5866** <li> SQLITE_MUTEX_OS2
5867** <li> SQLITE_MUTEX_PTHREAD
5868** <li> SQLITE_MUTEX_W32
5869** <li> SQLITE_MUTEX_NOOP
5870** </ul>
5871**
5872** The SQLITE_MUTEX_NOOP implementation is a set of routines
5873** that does no real locking and is appropriate for use in
5874** a single-threaded application. The SQLITE_MUTEX_OS2,
5875** SQLITE_MUTEX_PTHREAD, and SQLITE_MUTEX_W32 implementations
5876** are appropriate for use on OS/2, Unix, and Windows.
5877**
5878** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
5879** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
5880** implementation is included with the library. In this case the
5881** application must supply a custom mutex implementation using the
5882** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
5883** before calling sqlite3_initialize() or any other public sqlite3_
5884** function that calls sqlite3_initialize().
5885**
5886** {H17011} The sqlite3_mutex_alloc() routine allocates a new
5887** mutex and returns a pointer to it. {H17012} If it returns NULL
5888** that means that a mutex could not be allocated. {H17013} SQLite
5889** will unwind its stack and return an error. {H17014} The argument
5890** to sqlite3_mutex_alloc() is one of these integer constants:
5891**
5892** <ul>
5893** <li> SQLITE_MUTEX_FAST
5894** <li> SQLITE_MUTEX_RECURSIVE
5895** <li> SQLITE_MUTEX_STATIC_MASTER
5896** <li> SQLITE_MUTEX_STATIC_MEM
5897** <li> SQLITE_MUTEX_STATIC_MEM2
5898** <li> SQLITE_MUTEX_STATIC_PRNG
5899** <li> SQLITE_MUTEX_STATIC_LRU
5900** <li> SQLITE_MUTEX_STATIC_LRU2
5901** </ul>
5902**
5903** {H17015} The first two constants cause sqlite3_mutex_alloc() to create
5904** a new mutex. The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
5905** is used but not necessarily so when SQLITE_MUTEX_FAST is used. {END}
5906** The mutex implementation does not need to make a distinction
5907** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
5908** not want to. {H17016} But SQLite will only request a recursive mutex in
5909** cases where it really needs one. {END} If a faster non-recursive mutex
5910** implementation is available on the host platform, the mutex subsystem
5911** might return such a mutex in response to SQLITE_MUTEX_FAST.
5912**
5913** {H17017} The other allowed parameters to sqlite3_mutex_alloc() each return
5914** a pointer to a static preexisting mutex. {END} Four static mutexes are
5915** used by the current version of SQLite. Future versions of SQLite
5916** may add additional static mutexes. Static mutexes are for internal
5917** use by SQLite only. Applications that use SQLite mutexes should
5918** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
5919** SQLITE_MUTEX_RECURSIVE.
5920**
5921** {H17018} Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
5922** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
5923** returns a different mutex on every call. {H17034} But for the static
5924** mutex types, the same mutex is returned on every call that has
5925** the same type number.
5926**
5927** {H17019} The sqlite3_mutex_free() routine deallocates a previously
5928** allocated dynamic mutex. {H17020} SQLite is careful to deallocate every
5929** dynamic mutex that it allocates. {A17021} The dynamic mutexes must not be in
5930** use when they are deallocated. {A17022} Attempting to deallocate a static
5931** mutex results in undefined behavior. {H17023} SQLite never deallocates
5932** a static mutex. {END}
5933**
5934** The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
5935** to enter a mutex. {H17024} If another thread is already within the mutex,
5936** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
5937** SQLITE_BUSY. {H17025} The sqlite3_mutex_try() interface returns [SQLITE_OK]
5938** upon successful entry. {H17026} Mutexes created using
5939** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
5940** {H17027} In such cases the,
5941** mutex must be exited an equal number of times before another thread
5942** can enter. {A17028} If the same thread tries to enter any other
5943** kind of mutex more than once, the behavior is undefined.
5944** {H17029} SQLite will never exhibit
5945** such behavior in its own use of mutexes.
5946**
5947** Some systems (for example, Windows 95) do not support the operation
5948** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try()
5949** will always return SQLITE_BUSY. {H17030} The SQLite core only ever uses
5950** sqlite3_mutex_try() as an optimization so this is acceptable behavior.
5951**
5952** {H17031} The sqlite3_mutex_leave() routine exits a mutex that was
5953** previously entered by the same thread. {A17032} The behavior
5954** is undefined if the mutex is not currently entered by the
5955** calling thread or is not currently allocated. {H17033} SQLite will
5956** never do either. {END}
5957**
5958** If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or
5959** sqlite3_mutex_leave() is a NULL pointer, then all three routines
5960** behave as no-ops.
5961**
5962** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
5963*/
5964sqlite3_mutex *sqlite3_mutex_alloc(int);
5965void sqlite3_mutex_free(sqlite3_mutex*);
5966void sqlite3_mutex_enter(sqlite3_mutex*);
5967int sqlite3_mutex_try(sqlite3_mutex*);
5968void sqlite3_mutex_leave(sqlite3_mutex*);
5969
5970/*
5971** CAPI3REF: Mutex Methods Object {H17120} <S20130>
5972** EXPERIMENTAL
5973**
5974** An instance of this structure defines the low-level routines
5975** used to allocate and use mutexes.
5976**
5977** Usually, the default mutex implementations provided by SQLite are
5978** sufficient, however the user has the option of substituting a custom
5979** implementation for specialized deployments or systems for which SQLite
5980** does not provide a suitable implementation. In this case, the user
5981** creates and populates an instance of this structure to pass
5982** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
5983** Additionally, an instance of this structure can be used as an
5984** output variable when querying the system for the current mutex
5985** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
5986**
5987** The xMutexInit method defined by this structure is invoked as
5988** part of system initialization by the sqlite3_initialize() function.
5989** {H17001} The xMutexInit routine shall be called by SQLite once for each
5990** effective call to [sqlite3_initialize()].
5991**
5992** The xMutexEnd method defined by this structure is invoked as
5993** part of system shutdown by the sqlite3_shutdown() function. The
5994** implementation of this method is expected to release all outstanding
5995** resources obtained by the mutex methods implementation, especially
5996** those obtained by the xMutexInit method. {H17003} The xMutexEnd()
5997** interface shall be invoked once for each call to [sqlite3_shutdown()].
5998**
5999** The remaining seven methods defined by this structure (xMutexAlloc,
6000** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
6001** xMutexNotheld) implement the following interfaces (respectively):
6002**
6003** <ul>
6004** <li> [sqlite3_mutex_alloc()] </li>
6005** <li> [sqlite3_mutex_free()] </li>
6006** <li> [sqlite3_mutex_enter()] </li>
6007** <li> [sqlite3_mutex_try()] </li>
6008** <li> [sqlite3_mutex_leave()] </li>
6009** <li> [sqlite3_mutex_held()] </li>
6010** <li> [sqlite3_mutex_notheld()] </li>
6011** </ul>
6012**
6013** The only difference is that the public sqlite3_XXX functions enumerated
6014** above silently ignore any invocations that pass a NULL pointer instead
6015** of a valid mutex handle. The implementations of the methods defined
6016** by this structure are not required to handle this case, the results
6017** of passing a NULL pointer instead of a valid mutex handle are undefined
6018** (i.e. it is acceptable to provide an implementation that segfaults if
6019** it is passed a NULL pointer).
6020*/
6021typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
6022struct sqlite3_mutex_methods {
6023 int (*xMutexInit)(void);
6024 int (*xMutexEnd)(void);
6025 sqlite3_mutex *(*xMutexAlloc)(int);
6026 void (*xMutexFree)(sqlite3_mutex *);
6027 void (*xMutexEnter)(sqlite3_mutex *);
6028 int (*xMutexTry)(sqlite3_mutex *);
6029 void (*xMutexLeave)(sqlite3_mutex *);
6030 int (*xMutexHeld)(sqlite3_mutex *);
6031 int (*xMutexNotheld)(sqlite3_mutex *);
6032};
6033
6034/*
6035** CAPI3REF: Mutex Verification Routines {H17080} <S20130> <S30800>
6036**
6037** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
6038** are intended for use inside assert() statements. {H17081} The SQLite core
6039** never uses these routines except inside an assert() and applications
6040** are advised to follow the lead of the core. {H17082} The core only
6041** provides implementations for these routines when it is compiled
6042** with the SQLITE_DEBUG flag. {A17087} External mutex implementations
6043** are only required to provide these routines if SQLITE_DEBUG is
6044** defined and if NDEBUG is not defined.
6045**
6046** {H17083} These routines should return true if the mutex in their argument
6047** is held or not held, respectively, by the calling thread.
6048**
6049** {X17084} The implementation is not required to provided versions of these
6050** routines that actually work. If the implementation does not provide working
6051** versions of these routines, it should at least provide stubs that always
6052** return true so that one does not get spurious assertion failures.
6053**
6054** {H17085} If the argument to sqlite3_mutex_held() is a NULL pointer then
6055** the routine should return 1. {END} This seems counter-intuitive since
6056** clearly the mutex cannot be held if it does not exist. But the
6057** the reason the mutex does not exist is because the build is not
6058** using mutexes. And we do not want the assert() containing the
6059** call to sqlite3_mutex_held() to fail, so a non-zero return is
6060** the appropriate thing to do. {H17086} The sqlite3_mutex_notheld()
6061** interface should also return 1 when given a NULL pointer.
6062*/
6063int sqlite3_mutex_held(sqlite3_mutex*);
6064int sqlite3_mutex_notheld(sqlite3_mutex*);
6065
6066/*
6067** CAPI3REF: Mutex Types {H17001} <H17000>
6068**
6069** The [sqlite3_mutex_alloc()] interface takes a single argument
6070** which is one of these integer constants.
6071**
6072** The set of static mutexes may change from one SQLite release to the
6073** next. Applications that override the built-in mutex logic must be
6074** prepared to accommodate additional static mutexes.
6075*/
6076#define SQLITE_MUTEX_FAST 0
6077#define SQLITE_MUTEX_RECURSIVE 1
6078#define SQLITE_MUTEX_STATIC_MASTER 2
6079#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */
6080#define SQLITE_MUTEX_STATIC_MEM2 4 /* sqlite3_release_memory() */
6081#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */
6082#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */
6083#define SQLITE_MUTEX_STATIC_LRU2 7 /* lru page list */
6084
6085/*
6086** CAPI3REF: Low-Level Control Of Database Files {H11300} <S30800>
6087**
6088** {H11301} The [sqlite3_file_control()] interface makes a direct call to the
6089** xFileControl method for the [sqlite3_io_methods] object associated
6090** with a particular database identified by the second argument. {H11302} The
6091** name of the database is the name assigned to the database by the
6092** <a href="lang_attach.html">ATTACH</a> SQL command that opened the
6093** database. {H11303} To control the main database file, use the name "main"
6094** or a NULL pointer. {H11304} The third and fourth parameters to this routine
6095** are passed directly through to the second and third parameters of
6096** the xFileControl method. {H11305} The return value of the xFileControl
6097** method becomes the return value of this routine.
6098**
6099** {H11306} If the second parameter (zDbName) does not match the name of any
6100** open database file, then SQLITE_ERROR is returned. {H11307} This error
6101** code is not remembered and will not be recalled by [sqlite3_errcode()]
6102** or [sqlite3_errmsg()]. {A11308} The underlying xFileControl method might
6103** also return SQLITE_ERROR. {A11309} There is no way to distinguish between
6104** an incorrect zDbName and an SQLITE_ERROR return from the underlying
6105** xFileControl method. {END}
6106**
6107** See also: [SQLITE_FCNTL_LOCKSTATE]
6108*/
6109int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
6110
6111/*
6112** CAPI3REF: Testing Interface {H11400} <S30800>
6113**
6114** The sqlite3_test_control() interface is used to read out internal
6115** state of SQLite and to inject faults into SQLite for testing
6116** purposes. The first parameter is an operation code that determines
6117** the number, meaning, and operation of all subsequent parameters.
6118**
6119** This interface is not for use by applications. It exists solely
6120** for verifying the correct operation of the SQLite library. Depending
6121** on how the SQLite library is compiled, this interface might not exist.
6122**
6123** The details of the operation codes, their meanings, the parameters
6124** they take, and what they do are all subject to change without notice.
6125** Unlike most of the SQLite API, this function is not guaranteed to
6126** operate consistently from one release to the next.
6127*/
6128int sqlite3_test_control(int op, ...);
6129
6130/*
6131** CAPI3REF: Testing Interface Operation Codes {H11410} <H11400>
6132**
6133** These constants are the valid operation code parameters used
6134** as the first argument to [sqlite3_test_control()].
6135**
6136** These parameters and their meanings are subject to change
6137** without notice. These values are for testing purposes only.
6138** Applications should not use any of these parameters or the
6139** [sqlite3_test_control()] interface.
6140*/
6141#define SQLITE_TESTCTRL_PRNG_SAVE 5
6142#define SQLITE_TESTCTRL_PRNG_RESTORE 6
6143#define SQLITE_TESTCTRL_PRNG_RESET 7
6144#define SQLITE_TESTCTRL_BITVEC_TEST 8
6145#define SQLITE_TESTCTRL_FAULT_INSTALL 9
6146#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10
6147
6148/*
6149** CAPI3REF: SQLite Runtime Status {H17200} <S60200>
6150** EXPERIMENTAL
6151**
6152** This interface is used to retrieve runtime status information
6153** about the preformance of SQLite, and optionally to reset various
6154** highwater marks. The first argument is an integer code for
6155** the specific parameter to measure. Recognized integer codes
6156** are of the form [SQLITE_STATUS_MEMORY_USED | SQLITE_STATUS_...].
6157** The current value of the parameter is returned into *pCurrent.
6158** The highest recorded value is returned in *pHighwater. If the
6159** resetFlag is true, then the highest record value is reset after
6160** *pHighwater is written. Some parameters do not record the highest
6161** value. For those parameters
6162** nothing is written into *pHighwater and the resetFlag is ignored.
6163** Other parameters record only the highwater mark and not the current
6164** value. For these latter parameters nothing is written into *pCurrent.
6165**
6166** This routine returns SQLITE_OK on success and a non-zero
6167** [error code] on failure.
6168**
6169** This routine is threadsafe but is not atomic. This routine can
6170** called while other threads are running the same or different SQLite
6171** interfaces. However the values returned in *pCurrent and
6172** *pHighwater reflect the status of SQLite at different points in time
6173** and it is possible that another thread might change the parameter
6174** in between the times when *pCurrent and *pHighwater are written.
6175**
6176** See also: [sqlite3_db_status()]
6177*/
6178SQLITE_EXPERIMENTAL int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
6179
6180/*
6181** CAPI3REF: Database Connection Status {H17201} <S60200>
6182** EXPERIMENTAL
6183**
6184** This interface is used to retrieve runtime status information
6185** about a single [database connection]. The first argument is the
6186** database connection object to be interrogated. The second argument
6187** is the parameter to interrogate. Currently, the only allowed value
6188** for the second parameter is [SQLITE_DBSTATUS_LOOKASIDE_USED].
6189** Additional options will likely appear in future releases of SQLite.
6190**
6191** The current value of the request parameter is written into *pCur
6192** and the highest instantaneous value is written into *pHiwtr. If
6193** the resetFlg is true, then the highest instantaneous value is
6194** reset back down to the current value.
6195**
6196** See also: [sqlite3_status()].
6197*/
6198SQLITE_EXPERIMENTAL int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
6199
6200/*
6201** CAPI3REF: Status Parameters {H17250} <H17200>
6202** EXPERIMENTAL
6203**
6204** These integer constants designate various run-time status parameters
6205** that can be returned by [sqlite3_status()].
6206**
6207** <dl>
6208** <dt>SQLITE_STATUS_MEMORY_USED</dt>
6209** <dd>This parameter is the current amount of memory checked out
6210** using [sqlite3_malloc()], either directly or indirectly. The
6211** figure includes calls made to [sqlite3_malloc()] by the application
6212** and internal memory usage by the SQLite library. Scratch memory
6213** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache
6214** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
6215** this parameter. The amount returned is the sum of the allocation
6216** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>
6217**
6218** <dt>SQLITE_STATUS_MALLOC_SIZE</dt>
6219** <dd>This parameter records the largest memory allocation request
6220** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
6221** internal equivalents). Only the value returned in the
6222** *pHighwater parameter to [sqlite3_status()] is of interest.
6223** The value written into the *pCurrent parameter is undefined.</dd>
6224**
6225** <dt>SQLITE_STATUS_PAGECACHE_USED</dt>
6226** <dd>This parameter returns the number of pages used out of the
6227** [pagecache memory allocator] that was configured using
6228** [SQLITE_CONFIG_PAGECACHE]. The
6229** value returned is in pages, not in bytes.</dd>
6230**
6231** <dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
6232** <dd>This parameter returns the number of bytes of page cache
6233** allocation which could not be statisfied by the [SQLITE_CONFIG_PAGECACHE]
6234** buffer and where forced to overflow to [sqlite3_malloc()]. The
6235** returned value includes allocations that overflowed because they
6236** where too large (they were larger than the "sz" parameter to
6237** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
6238** no space was left in the page cache.</dd>
6239**
6240** <dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
6241** <dd>This parameter records the largest memory allocation request
6242** handed to [pagecache memory allocator]. Only the value returned in the
6243** *pHighwater parameter to [sqlite3_status()] is of interest.
6244** The value written into the *pCurrent parameter is undefined.</dd>
6245**
6246** <dt>SQLITE_STATUS_SCRATCH_USED</dt>
6247** <dd>This parameter returns the number of allocations used out of the
6248** [scratch memory allocator] configured using
6249** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not
6250** in bytes. Since a single thread may only have one scratch allocation
6251** outstanding at time, this parameter also reports the number of threads
6252** using scratch memory at the same time.</dd>
6253**
6254** <dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
6255** <dd>This parameter returns the number of bytes of scratch memory
6256** allocation which could not be statisfied by the [SQLITE_CONFIG_SCRATCH]
6257** buffer and where forced to overflow to [sqlite3_malloc()]. The values
6258** returned include overflows because the requested allocation was too
6259** larger (that is, because the requested allocation was larger than the
6260** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer
6261** slots were available.
6262** </dd>
6263**
6264** <dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
6265** <dd>This parameter records the largest memory allocation request
6266** handed to [scratch memory allocator]. Only the value returned in the
6267** *pHighwater parameter to [sqlite3_status()] is of interest.
6268** The value written into the *pCurrent parameter is undefined.</dd>
6269**
6270** <dt>SQLITE_STATUS_PARSER_STACK</dt>
6271** <dd>This parameter records the deepest parser stack. It is only
6272** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>
6273** </dl>
6274**
6275** New status parameters may be added from time to time.
6276*/
6277#define SQLITE_STATUS_MEMORY_USED 0
6278#define SQLITE_STATUS_PAGECACHE_USED 1
6279#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2
6280#define SQLITE_STATUS_SCRATCH_USED 3
6281#define SQLITE_STATUS_SCRATCH_OVERFLOW 4
6282#define SQLITE_STATUS_MALLOC_SIZE 5
6283#define SQLITE_STATUS_PARSER_STACK 6
6284#define SQLITE_STATUS_PAGECACHE_SIZE 7
6285#define SQLITE_STATUS_SCRATCH_SIZE 8
6286
6287/*
6288** CAPI3REF: Status Parameters for database connections {H17275} <H17200>
6289** EXPERIMENTAL
6290**
6291** Status verbs for [sqlite3_db_status()].
6292**
6293** <dl>
6294** <dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
6295** <dd>This parameter returns the number of lookaside memory slots currently
6296** checked out.</dd>
6297** </dl>
6298*/
6299#define SQLITE_DBSTATUS_LOOKASIDE_USED 0
6300
6301/*
6302** Undo the hack that converts floating point types to integer for
6303** builds on processors without floating point support.
6304*/
6305#ifdef SQLITE_OMIT_FLOATING_POINT
6306# undef double
6307#endif
6308
6309#ifdef __cplusplus
6310} /* End of the 'extern "C"' block */
6311#endif
6312#endif