sqlite3.h revision 7790ef5367fe6731048c3e3a1c067f94b321cb4d
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 1.312 2008/05/12 12:39:56 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** Make sure these symbols where not defined by some previous header 56** file. 57*/ 58#ifdef SQLITE_VERSION 59# undef SQLITE_VERSION 60#endif 61#ifdef SQLITE_VERSION_NUMBER 62# undef SQLITE_VERSION_NUMBER 63#endif 64 65/* 66** CAPI3REF: Compile-Time Library Version Numbers {F10010} 67** 68** The SQLITE_VERSION and SQLITE_VERSION_NUMBER #defines in 69** the sqlite3.h file specify the version of SQLite with which 70** that header file is associated. 71** 72** The "version" of SQLite is a string of the form "X.Y.Z". 73** The phrase "alpha" or "beta" might be appended after the Z. 74** The X value is major version number always 3 in SQLite3. 75** The X value only changes when backwards compatibility is 76** broken and we intend to never break 77** backwards compatibility. The Y value is the minor version 78** number and only changes when 79** there are major feature enhancements that are forwards compatible 80** but not backwards compatible. The Z value is release number 81** and is incremented with 82** each release but resets back to 0 when Y is incremented. 83** 84** See also: [sqlite3_libversion()] and [sqlite3_libversion_number()]. 85** 86** INVARIANTS: 87** 88** {F10011} The SQLITE_VERSION #define in the sqlite3.h header file 89** evaluates to a string literal that is the SQLite version 90** with which the header file is associated. 91** 92** {F10014} The SQLITE_VERSION_NUMBER #define resolves to an integer 93** with the value (X*1000000 + Y*1000 + Z) where X, Y, and 94** Z are the major version, minor version, and release number. 95*/ 96#define SQLITE_VERSION "3.5.9" 97#define SQLITE_VERSION_NUMBER 3005009 98 99/* 100** CAPI3REF: Run-Time Library Version Numbers {F10020} 101** KEYWORDS: sqlite3_version 102** 103** These features provide the same information as the [SQLITE_VERSION] 104** and [SQLITE_VERSION_NUMBER] #defines in the header, but are associated 105** with the library instead of the header file. Cautious programmers might 106** include a check in their application to verify that 107** sqlite3_libversion_number() always returns the value 108** [SQLITE_VERSION_NUMBER]. 109** 110** The sqlite3_libversion() function returns the same information as is 111** in the sqlite3_version[] string constant. The function is provided 112** for use in DLLs since DLL users usually do not have direct access to string 113** constants within the DLL. 114** 115** INVARIANTS: 116** 117** {F10021} The [sqlite3_libversion_number()] interface returns an integer 118** equal to [SQLITE_VERSION_NUMBER]. 119** 120** {F10022} The [sqlite3_version] string constant contains the text of the 121** [SQLITE_VERSION] string. 122** 123** {F10023} The [sqlite3_libversion()] function returns 124** a pointer to the [sqlite3_version] string constant. 125*/ 126SQLITE_EXTERN const char sqlite3_version[]; 127const char *sqlite3_libversion(void); 128int sqlite3_libversion_number(void); 129 130/* 131** CAPI3REF: Test To See If The Library Is Threadsafe {F10100} 132** 133** SQLite can be compiled with or without mutexes. When 134** the SQLITE_THREADSAFE C preprocessor macro is true, mutexes 135** are enabled and SQLite is threadsafe. When that macro is false, 136** the mutexes are omitted. Without the mutexes, it is not safe 137** to use SQLite from more than one thread. 138** 139** There is a measurable performance penalty for enabling mutexes. 140** So if speed is of utmost importance, it makes sense to disable 141** the mutexes. But for maximum safety, mutexes should be enabled. 142** The default behavior is for mutexes to be enabled. 143** 144** This interface can be used by a program to make sure that the 145** version of SQLite that it is linking against was compiled with 146** the desired setting of the SQLITE_THREADSAFE macro. 147** 148** INVARIANTS: 149** 150** {F10101} The [sqlite3_threadsafe()] function returns nonzero if 151** SQLite was compiled with its mutexes enabled or zero 152** if SQLite was compiled with mutexes disabled. 153*/ 154int sqlite3_threadsafe(void); 155 156/* 157** CAPI3REF: Database Connection Handle {F12000} 158** KEYWORDS: {database connection} {database connections} 159** 160** Each open SQLite database is represented by pointer to an instance of the 161** opaque structure named "sqlite3". It is useful to think of an sqlite3 162** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 163** [sqlite3_open_v2()] interfaces are its constructors 164** and [sqlite3_close()] is its destructor. There are many other interfaces 165** (such as [sqlite3_prepare_v2()], [sqlite3_create_function()], and 166** [sqlite3_busy_timeout()] to name but three) that are methods on this 167** object. 168*/ 169typedef struct sqlite3 sqlite3; 170 171 172/* 173** CAPI3REF: 64-Bit Integer Types {F10200} 174** KEYWORDS: sqlite_int64 sqlite_uint64 175** 176** Because there is no cross-platform way to specify 64-bit integer types 177** SQLite includes typedefs for 64-bit signed and unsigned integers. 178** 179** The sqlite3_int64 and sqlite3_uint64 are the preferred type 180** definitions. The sqlite_int64 and sqlite_uint64 types are 181** supported for backwards compatibility only. 182** 183** INVARIANTS: 184** 185** {F10201} The [sqlite_int64] and [sqlite3_int64] types specify a 186** 64-bit signed integer. 187** 188** {F10202} The [sqlite_uint64] and [sqlite3_uint64] types specify 189** a 64-bit unsigned integer. 190*/ 191#ifdef SQLITE_INT64_TYPE 192 typedef SQLITE_INT64_TYPE sqlite_int64; 193 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 194#elif defined(_MSC_VER) || defined(__BORLANDC__) 195 typedef __int64 sqlite_int64; 196 typedef unsigned __int64 sqlite_uint64; 197#else 198 typedef long long int sqlite_int64; 199 typedef unsigned long long int sqlite_uint64; 200#endif 201typedef sqlite_int64 sqlite3_int64; 202typedef sqlite_uint64 sqlite3_uint64; 203 204/* 205** If compiling for a processor that lacks floating point support, 206** substitute integer for floating-point 207*/ 208#ifdef SQLITE_OMIT_FLOATING_POINT 209# define double sqlite3_int64 210#endif 211 212/* 213** CAPI3REF: Closing A Database Connection {F12010} 214** 215** This routine is the destructor for the [sqlite3] object. 216** 217** Applications should [sqlite3_finalize | finalize] all 218** [prepared statements] and 219** [sqlite3_blob_close | close] all [sqlite3_blob | BLOBs] 220** associated with the [sqlite3] object prior 221** to attempting to close the [sqlite3] object. 222** 223** <todo>What happens to pending transactions? Are they 224** rolled back, or abandoned?</todo> 225** 226** INVARIANTS: 227** 228** {F12011} The [sqlite3_close()] interface destroys an [sqlite3] object 229** allocated by a prior call to [sqlite3_open()], 230** [sqlite3_open16()], or [sqlite3_open_v2()]. 231** 232** {F12012} The [sqlite3_close()] function releases all memory used by the 233** connection and closes all open files. 234** 235** {F12013} If the database connection contains 236** [prepared statements] that have not been 237** finalized by [sqlite3_finalize()], then [sqlite3_close()] 238** returns [SQLITE_BUSY] and leaves the connection open. 239** 240** {F12014} Giving sqlite3_close() a NULL pointer is a harmless no-op. 241** 242** LIMITATIONS: 243** 244** {U12015} The parameter to [sqlite3_close()] must be an [sqlite3] object 245** pointer previously obtained from [sqlite3_open()] or the 246** equivalent, or NULL. 247** 248** {U12016} The parameter to [sqlite3_close()] must not have been previously 249** closed. 250*/ 251int sqlite3_close(sqlite3 *); 252 253/* 254** The type for a callback function. 255** This is legacy and deprecated. It is included for historical 256** compatibility and is not documented. 257*/ 258typedef int (*sqlite3_callback)(void*,int,char**, char**); 259 260/* 261** CAPI3REF: One-Step Query Execution Interface {F12100} 262** 263** The sqlite3_exec() interface is a convenient way of running 264** one or more SQL statements without a lot of C code. The 265** SQL statements are passed in as the second parameter to 266** sqlite3_exec(). The statements are evaluated one by one 267** until either an error or an interrupt is encountered or 268** until they are all done. The 3rd parameter is an optional 269** callback that is invoked once for each row of any query results 270** produced by the SQL statements. The 5th parameter tells where 271** to write any error messages. 272** 273** The sqlite3_exec() interface is implemented in terms of 274** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()]. 275** The sqlite3_exec() routine does nothing that cannot be done 276** by [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()]. 277** The sqlite3_exec() is just a convenient wrapper. 278** 279** INVARIANTS: 280** 281** {F12101} The [sqlite3_exec()] interface evaluates zero or more UTF-8 282** encoded, semicolon-separated, SQL statements in the 283** zero-terminated string of its 2nd parameter within the 284** context of the [sqlite3] object given in the 1st parameter. 285** 286** {F12104} The return value of [sqlite3_exec()] is SQLITE_OK if all 287** SQL statements run successfully. 288** 289** {F12105} The return value of [sqlite3_exec()] is an appropriate 290** non-zero error code if any SQL statement fails. 291** 292** {F12107} If one or more of the SQL statements handed to [sqlite3_exec()] 293** return results and the 3rd parameter is not NULL, then 294** the callback function specified by the 3rd parameter is 295** invoked once for each row of result. 296** 297** {F12110} If the callback returns a non-zero value then [sqlite3_exec()] 298** will aborted the SQL statement it is currently evaluating, 299** skip all subsequent SQL statements, and return [SQLITE_ABORT]. 300** <todo>What happens to *errmsg here? Does the result code for 301** sqlite3_errcode() get set?</todo> 302** 303** {F12113} The [sqlite3_exec()] routine will pass its 4th parameter through 304** as the 1st parameter of the callback. 305** 306** {F12116} The [sqlite3_exec()] routine sets the 2nd parameter of its 307** callback to be the number of columns in the current row of 308** result. 309** 310** {F12119} The [sqlite3_exec()] routine sets the 3rd parameter of its 311** callback to be an array of pointers to strings holding the 312** values for each column in the current result set row as 313** obtained from [sqlite3_column_text()]. 314** 315** {F12122} The [sqlite3_exec()] routine sets the 4th parameter of its 316** callback to be an array of pointers to strings holding the 317** names of result columns as obtained from [sqlite3_column_name()]. 318** 319** {F12125} If the 3rd parameter to [sqlite3_exec()] is NULL then 320** [sqlite3_exec()] never invokes a callback. All query 321** results are silently discarded. 322** 323** {F12128} If an error occurs while parsing or evaluating any of the SQL 324** statements handed to [sqlite3_exec()] then [sqlite3_exec()] will 325** return an [error code] other than [SQLITE_OK]. 326** 327** {F12131} If an error occurs while parsing or evaluating any of the SQL 328** handed to [sqlite3_exec()] and if the 5th parameter (errmsg) 329** to [sqlite3_exec()] is not NULL, then an error message is 330** allocated using the equivalent of [sqlite3_mprintf()] and 331** *errmsg is made to point to that message. 332** 333** {F12134} The [sqlite3_exec()] routine does not change the value of 334** *errmsg if errmsg is NULL or if there are no errors. 335** 336** {F12137} The [sqlite3_exec()] function sets the error code and message 337** accessible via [sqlite3_errcode()], [sqlite3_errmsg()], and 338** [sqlite3_errmsg16()]. 339** 340** LIMITATIONS: 341** 342** {U12141} The first parameter to [sqlite3_exec()] must be an valid and open 343** [database connection]. 344** 345** {U12142} The database connection must not be closed while 346** [sqlite3_exec()] is running. 347** 348** {U12143} The calling function is should use [sqlite3_free()] to free 349** the memory that *errmsg is left pointing at once the error 350** message is no longer needed. 351** 352** {U12145} The SQL statement text in the 2nd parameter to [sqlite3_exec()] 353** must remain unchanged while [sqlite3_exec()] is running. 354*/ 355int sqlite3_exec( 356 sqlite3*, /* An open database */ 357 const char *sql, /* SQL to be evaluted */ 358 int (*callback)(void*,int,char**,char**), /* Callback function */ 359 void *, /* 1st argument to callback */ 360 char **errmsg /* Error msg written here */ 361); 362 363/* 364** CAPI3REF: Result Codes {F10210} 365** KEYWORDS: SQLITE_OK {error code} {error codes} 366** 367** Many SQLite functions return an integer result code from the set shown 368** here in order to indicates success or failure. 369** 370** See also: [SQLITE_IOERR_READ | extended result codes] 371*/ 372#define SQLITE_OK 0 /* Successful result */ 373/* beginning-of-error-codes */ 374#define SQLITE_ERROR 1 /* SQL error or missing database */ 375#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 376#define SQLITE_PERM 3 /* Access permission denied */ 377#define SQLITE_ABORT 4 /* Callback routine requested an abort */ 378#define SQLITE_BUSY 5 /* The database file is locked */ 379#define SQLITE_LOCKED 6 /* A table in the database is locked */ 380#define SQLITE_NOMEM 7 /* A malloc() failed */ 381#define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 382#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 383#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 384#define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 385#define SQLITE_NOTFOUND 12 /* NOT USED. Table or record not found */ 386#define SQLITE_FULL 13 /* Insertion failed because database is full */ 387#define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 388#define SQLITE_PROTOCOL 15 /* NOT USED. Database lock protocol error */ 389#define SQLITE_EMPTY 16 /* Database is empty */ 390#define SQLITE_SCHEMA 17 /* The database schema changed */ 391#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 392#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 393#define SQLITE_MISMATCH 20 /* Data type mismatch */ 394#define SQLITE_MISUSE 21 /* Library used incorrectly */ 395#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 396#define SQLITE_AUTH 23 /* Authorization denied */ 397#define SQLITE_FORMAT 24 /* Auxiliary database format error */ 398#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 399#define SQLITE_NOTADB 26 /* File opened that is not a database file */ 400#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 401#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 402/* end-of-error-codes */ 403 404/* 405** CAPI3REF: Extended Result Codes {F10220} 406** KEYWORDS: {extended error code} {extended error codes} 407** KEYWORDS: {extended result codes} 408** 409** In its default configuration, SQLite API routines return one of 26 integer 410** [SQLITE_OK | result codes]. However, experience has shown that 411** many of these result codes are too course-grained. They do not provide as 412** much information about problems as programmers might like. In an effort to 413** address this, newer versions of SQLite (version 3.3.8 and later) include 414** support for additional result codes that provide more detailed information 415** about errors. The extended result codes are enabled or disabled 416** for each database connection using the [sqlite3_extended_result_codes()] 417** API. 418** 419** Some of the available extended result codes are listed here. 420** One may expect the number of extended result codes will be expand 421** over time. Software that uses extended result codes should expect 422** to see new result codes in future releases of SQLite. 423** 424** The SQLITE_OK result code will never be extended. It will always 425** be exactly zero. 426** 427** INVARIANTS: 428** 429** {F10223} The symbolic name for an extended result code always contains 430** a related primary result code as a prefix. 431** 432** {F10224} Primary result code names contain a single "_" character. 433** 434** {F10225} Extended result code names contain two or more "_" characters. 435** 436** {F10226} The numeric value of an extended result code contains the 437** numeric value of its corresponding primary result code in 438** its least significant 8 bits. 439*/ 440#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 441#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 442#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 443#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 444#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 445#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 446#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 447#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 448#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 449#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 450#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 451#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 452 453/* 454** CAPI3REF: Flags For File Open Operations {F10230} 455** 456** These bit values are intended for use in the 457** 3rd parameter to the [sqlite3_open_v2()] interface and 458** in the 4th parameter to the xOpen method of the 459** [sqlite3_vfs] object. 460*/ 461#define SQLITE_OPEN_READONLY 0x00000001 462#define SQLITE_OPEN_READWRITE 0x00000002 463#define SQLITE_OPEN_CREATE 0x00000004 464#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 465#define SQLITE_OPEN_EXCLUSIVE 0x00000010 466#define SQLITE_OPEN_MAIN_DB 0x00000100 467#define SQLITE_OPEN_TEMP_DB 0x00000200 468#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 469#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 470#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 471#define SQLITE_OPEN_SUBJOURNAL 0x00002000 472#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 473 474/* 475** CAPI3REF: Device Characteristics {F10240} 476** 477** The xDeviceCapabilities method of the [sqlite3_io_methods] 478** object returns an integer which is a vector of the these 479** bit values expressing I/O characteristics of the mass storage 480** device that holds the file that the [sqlite3_io_methods] 481** refers to. 482** 483** The SQLITE_IOCAP_ATOMIC property means that all writes of 484** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 485** mean that writes of blocks that are nnn bytes in size and 486** are aligned to an address which is an integer multiple of 487** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 488** that when data is appended to a file, the data is appended 489** first then the size of the file is extended, never the other 490** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 491** information is written to disk in the same order as calls 492** to xWrite(). 493*/ 494#define SQLITE_IOCAP_ATOMIC 0x00000001 495#define SQLITE_IOCAP_ATOMIC512 0x00000002 496#define SQLITE_IOCAP_ATOMIC1K 0x00000004 497#define SQLITE_IOCAP_ATOMIC2K 0x00000008 498#define SQLITE_IOCAP_ATOMIC4K 0x00000010 499#define SQLITE_IOCAP_ATOMIC8K 0x00000020 500#define SQLITE_IOCAP_ATOMIC16K 0x00000040 501#define SQLITE_IOCAP_ATOMIC32K 0x00000080 502#define SQLITE_IOCAP_ATOMIC64K 0x00000100 503#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 504#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 505 506/* 507** CAPI3REF: File Locking Levels {F10250} 508** 509** SQLite uses one of these integer values as the second 510** argument to calls it makes to the xLock() and xUnlock() methods 511** of an [sqlite3_io_methods] object. 512*/ 513#define SQLITE_LOCK_NONE 0 514#define SQLITE_LOCK_SHARED 1 515#define SQLITE_LOCK_RESERVED 2 516#define SQLITE_LOCK_PENDING 3 517#define SQLITE_LOCK_EXCLUSIVE 4 518 519/* 520** CAPI3REF: Synchronization Type Flags {F10260} 521** 522** When SQLite invokes the xSync() method of an 523** [sqlite3_io_methods] object it uses a combination of 524** these integer values as the second argument. 525** 526** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 527** sync operation only needs to flush data to mass storage. Inode 528** information need not be flushed. The SQLITE_SYNC_NORMAL flag means 529** to use normal fsync() semantics. The SQLITE_SYNC_FULL flag means 530** to use Mac OS-X style fullsync instead of fsync(). 531*/ 532#define SQLITE_SYNC_NORMAL 0x00002 533#define SQLITE_SYNC_FULL 0x00003 534#define SQLITE_SYNC_DATAONLY 0x00010 535 536 537/* 538** CAPI3REF: OS Interface Open File Handle {F11110} 539** 540** An [sqlite3_file] object represents an open file in the OS 541** interface layer. Individual OS interface implementations will 542** want to subclass this object by appending additional fields 543** for their own use. The pMethods entry is a pointer to an 544** [sqlite3_io_methods] object that defines methods for performing 545** I/O operations on the open file. 546*/ 547typedef struct sqlite3_file sqlite3_file; 548struct sqlite3_file { 549 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 550}; 551 552/* 553** CAPI3REF: OS Interface File Virtual Methods Object {F11120} 554** 555** Every file opened by the [sqlite3_vfs] xOpen method contains a pointer to 556** an instance of this object. This object defines the 557** methods used to perform various operations against the open file. 558** 559** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 560** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 561* The second choice is an 562** OS-X style fullsync. The SQLITE_SYNC_DATA flag may be ORed in to 563** indicate that only the data of the file and not its inode needs to be 564** synced. 565** 566** The integer values to xLock() and xUnlock() are one of 567** <ul> 568** <li> [SQLITE_LOCK_NONE], 569** <li> [SQLITE_LOCK_SHARED], 570** <li> [SQLITE_LOCK_RESERVED], 571** <li> [SQLITE_LOCK_PENDING], or 572** <li> [SQLITE_LOCK_EXCLUSIVE]. 573** </ul> 574** xLock() increases the lock. xUnlock() decreases the lock. 575** The xCheckReservedLock() method looks 576** to see if any database connection, either in this 577** process or in some other process, is holding an RESERVED, 578** PENDING, or EXCLUSIVE lock on the file. It returns true 579** if such a lock exists and false if not. 580** 581** The xFileControl() method is a generic interface that allows custom 582** VFS implementations to directly control an open file using the 583** [sqlite3_file_control()] interface. The second "op" argument 584** is an integer opcode. The third 585** argument is a generic pointer which is intended to be a pointer 586** to a structure that may contain arguments or space in which to 587** write return values. Potential uses for xFileControl() might be 588** functions to enable blocking locks with timeouts, to change the 589** locking strategy (for example to use dot-file locks), to inquire 590** about the status of a lock, or to break stale locks. The SQLite 591** core reserves opcodes less than 100 for its own use. 592** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available. 593** Applications that define a custom xFileControl method should use opcodes 594** greater than 100 to avoid conflicts. 595** 596** The xSectorSize() method returns the sector size of the 597** device that underlies the file. The sector size is the 598** minimum write that can be performed without disturbing 599** other bytes in the file. The xDeviceCharacteristics() 600** method returns a bit vector describing behaviors of the 601** underlying device: 602** 603** <ul> 604** <li> [SQLITE_IOCAP_ATOMIC] 605** <li> [SQLITE_IOCAP_ATOMIC512] 606** <li> [SQLITE_IOCAP_ATOMIC1K] 607** <li> [SQLITE_IOCAP_ATOMIC2K] 608** <li> [SQLITE_IOCAP_ATOMIC4K] 609** <li> [SQLITE_IOCAP_ATOMIC8K] 610** <li> [SQLITE_IOCAP_ATOMIC16K] 611** <li> [SQLITE_IOCAP_ATOMIC32K] 612** <li> [SQLITE_IOCAP_ATOMIC64K] 613** <li> [SQLITE_IOCAP_SAFE_APPEND] 614** <li> [SQLITE_IOCAP_SEQUENTIAL] 615** </ul> 616** 617** The SQLITE_IOCAP_ATOMIC property means that all writes of 618** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 619** mean that writes of blocks that are nnn bytes in size and 620** are aligned to an address which is an integer multiple of 621** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 622** that when data is appended to a file, the data is appended 623** first then the size of the file is extended, never the other 624** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 625** information is written to disk in the same order as calls 626** to xWrite(). 627*/ 628typedef struct sqlite3_io_methods sqlite3_io_methods; 629struct sqlite3_io_methods { 630 int iVersion; 631 int (*xClose)(sqlite3_file*); 632 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 633 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 634 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 635 int (*xSync)(sqlite3_file*, int flags); 636 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 637 int (*xLock)(sqlite3_file*, int); 638 int (*xUnlock)(sqlite3_file*, int); 639 int (*xCheckReservedLock)(sqlite3_file*); 640 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 641 int (*xSectorSize)(sqlite3_file*); 642 int (*xDeviceCharacteristics)(sqlite3_file*); 643 /* Additional methods may be added in future releases */ 644}; 645 646/* 647** CAPI3REF: Standard File Control Opcodes {F11310} 648** 649** These integer constants are opcodes for the xFileControl method 650** of the [sqlite3_io_methods] object and to the [sqlite3_file_control()] 651** interface. 652** 653** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 654** opcode causes the xFileControl method to write the current state of 655** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 656** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 657** into an integer that the pArg argument points to. This capability 658** is used during testing and only needs to be supported when SQLITE_TEST 659** is defined. 660*/ 661#define SQLITE_FCNTL_LOCKSTATE 1 662 663/* 664** CAPI3REF: Mutex Handle {F17110} 665** 666** The mutex module within SQLite defines [sqlite3_mutex] to be an 667** abstract type for a mutex object. The SQLite core never looks 668** at the internal representation of an [sqlite3_mutex]. It only 669** deals with pointers to the [sqlite3_mutex] object. 670** 671** Mutexes are created using [sqlite3_mutex_alloc()]. 672*/ 673typedef struct sqlite3_mutex sqlite3_mutex; 674 675/* 676** CAPI3REF: OS Interface Object {F11140} 677** 678** An instance of this object defines the interface between the 679** SQLite core and the underlying operating system. The "vfs" 680** in the name of the object stands for "virtual file system". 681** 682** The iVersion field is initially 1 but may be larger for future 683** versions of SQLite. Additional fields may be appended to this 684** object when the iVersion value is increased. 685** 686** The szOsFile field is the size of the subclassed [sqlite3_file] 687** structure used by this VFS. mxPathname is the maximum length of 688** a pathname in this VFS. 689** 690** Registered sqlite3_vfs objects are kept on a linked list formed by 691** the pNext pointer. The [sqlite3_vfs_register()] 692** and [sqlite3_vfs_unregister()] interfaces manage this list 693** in a thread-safe way. The [sqlite3_vfs_find()] interface 694** searches the list. 695** 696** The pNext field is the only field in the sqlite3_vfs 697** structure that SQLite will ever modify. SQLite will only access 698** or modify this field while holding a particular static mutex. 699** The application should never modify anything within the sqlite3_vfs 700** object once the object has been registered. 701** 702** The zName field holds the name of the VFS module. The name must 703** be unique across all VFS modules. 704** 705** {F11141} SQLite will guarantee that the zFilename string passed to 706** xOpen() is a full pathname as generated by xFullPathname() and 707** that the string will be valid and unchanged until xClose() is 708** called. {END} So the [sqlite3_file] can store a pointer to the 709** filename if it needs to remember the filename for some reason. 710** 711** {F11142} The flags argument to xOpen() includes all bits set in 712** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 713** or [sqlite3_open16()] is used, then flags includes at least 714** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. {END} 715** If xOpen() opens a file read-only then it sets *pOutFlags to 716** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be 717** set. 718** 719** {F11143} SQLite will also add one of the following flags to the xOpen() 720** call, depending on the object being opened: 721** 722** <ul> 723** <li> [SQLITE_OPEN_MAIN_DB] 724** <li> [SQLITE_OPEN_MAIN_JOURNAL] 725** <li> [SQLITE_OPEN_TEMP_DB] 726** <li> [SQLITE_OPEN_TEMP_JOURNAL] 727** <li> [SQLITE_OPEN_TRANSIENT_DB] 728** <li> [SQLITE_OPEN_SUBJOURNAL] 729** <li> [SQLITE_OPEN_MASTER_JOURNAL] 730** </ul> {END} 731** 732** The file I/O implementation can use the object type flags to 733** changes the way it deals with files. For example, an application 734** that does not care about crash recovery or rollback might make 735** the open of a journal file a no-op. Writes to this journal would 736** also be no-ops, and any attempt to read the journal would return 737** SQLITE_IOERR. Or the implementation might recognize that a database 738** file will be doing page-aligned sector reads and writes in a random 739** order and set up its I/O subsystem accordingly. 740** 741** SQLite might also add one of the following flags to the xOpen 742** method: 743** 744** <ul> 745** <li> [SQLITE_OPEN_DELETEONCLOSE] 746** <li> [SQLITE_OPEN_EXCLUSIVE] 747** </ul> 748** 749** {F11145} The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 750** deleted when it is closed. {F11146} The [SQLITE_OPEN_DELETEONCLOSE] 751** will be set for TEMP databases, journals and for subjournals. 752** {F11147} The [SQLITE_OPEN_EXCLUSIVE] flag means the file should be opened 753** for exclusive access. This flag is set for all files except 754** for the main database file. {END} 755** 756** {F11148} At least szOsFile bytes of memory are allocated by SQLite 757** to hold the [sqlite3_file] structure passed as the third 758** argument to xOpen. {END} The xOpen method does not have to 759** allocate the structure; it should just fill it in. 760** 761** {F11149} The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 762** to test for the existance of a file, 763** or [SQLITE_ACCESS_READWRITE] to test to see 764** if a file is readable and writable, or [SQLITE_ACCESS_READ] 765** to test to see if a file is at least readable. {END} The file can be a 766** directory. 767** 768** {F11150} SQLite will always allocate at least mxPathname+1 bytes for 769** the output buffers for xGetTempname and xFullPathname. {F11151} The exact 770** size of the output buffer is also passed as a parameter to both 771** methods. {END} If the output buffer is not large enough, SQLITE_CANTOPEN 772** should be returned. As this is handled as a fatal error by SQLite, 773** vfs implementations should endeavor to prevent this by setting 774** mxPathname to a sufficiently large value. 775** 776** The xRandomness(), xSleep(), and xCurrentTime() interfaces 777** are not strictly a part of the filesystem, but they are 778** included in the VFS structure for completeness. 779** The xRandomness() function attempts to return nBytes bytes 780** of good-quality randomness into zOut. The return value is 781** the actual number of bytes of randomness obtained. The 782** xSleep() method causes the calling thread to sleep for at 783** least the number of microseconds given. The xCurrentTime() 784** method returns a Julian Day Number for the current date and 785** time. 786*/ 787typedef struct sqlite3_vfs sqlite3_vfs; 788struct sqlite3_vfs { 789 int iVersion; /* Structure version number */ 790 int szOsFile; /* Size of subclassed sqlite3_file */ 791 int mxPathname; /* Maximum file pathname length */ 792 sqlite3_vfs *pNext; /* Next registered VFS */ 793 const char *zName; /* Name of this virtual file system */ 794 void *pAppData; /* Pointer to application-specific data */ 795 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 796 int flags, int *pOutFlags); 797 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 798 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags); 799 int (*xGetTempname)(sqlite3_vfs*, int nOut, char *zOut); 800 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 801 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 802 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 803 void *(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol); 804 void (*xDlClose)(sqlite3_vfs*, void*); 805 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 806 int (*xSleep)(sqlite3_vfs*, int microseconds); 807 int (*xCurrentTime)(sqlite3_vfs*, double*); 808 /* New fields may be appended in figure versions. The iVersion 809 ** value will increment whenever this happens. */ 810}; 811 812/* 813** CAPI3REF: Flags for the xAccess VFS method {F11190} 814** 815** {F11191} These integer constants can be used as the third parameter to 816** the xAccess method of an [sqlite3_vfs] object. {END} They determine 817** what kind of permissions the xAccess method is 818** looking for. {F11192} With SQLITE_ACCESS_EXISTS, the xAccess method 819** simply checks to see if the file exists. {F11193} With 820** SQLITE_ACCESS_READWRITE, the xAccess method checks to see 821** if the file is both readable and writable. {F11194} With 822** SQLITE_ACCESS_READ the xAccess method 823** checks to see if the file is readable. 824*/ 825#define SQLITE_ACCESS_EXISTS 0 826#define SQLITE_ACCESS_READWRITE 1 827#define SQLITE_ACCESS_READ 2 828 829/* 830** CAPI3REF: Enable Or Disable Extended Result Codes {F12200} 831** 832** The sqlite3_extended_result_codes() routine enables or disables the 833** [SQLITE_IOERR_READ | extended result codes] feature of SQLite. 834** The extended result codes are disabled by default for historical 835** compatibility. 836** 837** INVARIANTS: 838** 839** {F12201} Each new [database connection] has the 840** [extended result codes] feature 841** disabled by default. 842** 843** {F12202} The [sqlite3_extended_result_codes(D,F)] interface will enable 844** [extended result codes] for the 845** [database connection] D if the F parameter 846** is true, or disable them if F is false. 847*/ 848int sqlite3_extended_result_codes(sqlite3*, int onoff); 849 850/* 851** CAPI3REF: Last Insert Rowid {F12220} 852** 853** Each entry in an SQLite table has a unique 64-bit signed 854** integer key called the "rowid". The rowid is always available 855** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 856** names are not also used by explicitly declared columns. If 857** the table has a column of type INTEGER PRIMARY KEY then that column 858** is another alias for the rowid. 859** 860** This routine returns the rowid of the most recent 861** successful INSERT into the database from the database connection 862** shown in the first argument. If no successful inserts 863** have ever occurred on this database connection, zero is returned. 864** 865** If an INSERT occurs within a trigger, then the rowid of the 866** inserted row is returned by this routine as long as the trigger 867** is running. But once the trigger terminates, the value returned 868** by this routine reverts to the last value inserted before the 869** trigger fired. 870** 871** An INSERT that fails due to a constraint violation is not a 872** successful insert and does not change the value returned by this 873** routine. Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 874** and INSERT OR ABORT make no changes to the return value of this 875** routine when their insertion fails. When INSERT OR REPLACE 876** encounters a constraint violation, it does not fail. The 877** INSERT continues to completion after deleting rows that caused 878** the constraint problem so INSERT OR REPLACE will always change 879** the return value of this interface. 880** 881** For the purposes of this routine, an insert is considered to 882** be successful even if it is subsequently rolled back. 883** 884** INVARIANTS: 885** 886** {F12221} The [sqlite3_last_insert_rowid()] function returns the 887** rowid of the most recent successful insert done 888** on the same database connection and within the same 889** trigger context, or zero if there have 890** been no qualifying inserts on that connection. 891** 892** {F12223} The [sqlite3_last_insert_rowid()] function returns 893** same value when called from the same trigger context 894** immediately before and after a ROLLBACK. 895** 896** LIMITATIONS: 897** 898** {U12232} If a separate thread does a new insert on the same 899** database connection while the [sqlite3_last_insert_rowid()] 900** function is running and thus changes the last insert rowid, 901** then the value returned by [sqlite3_last_insert_rowid()] is 902** unpredictable and might not equal either the old or the new 903** last insert rowid. 904*/ 905sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 906 907/* 908** CAPI3REF: Count The Number Of Rows Modified {F12240} 909** 910** This function returns the number of database rows that were changed 911** or inserted or deleted by the most recently completed SQL statement 912** on the connection specified by the first parameter. Only 913** changes that are directly specified by the INSERT, UPDATE, or 914** DELETE statement are counted. Auxiliary changes caused by 915** triggers are not counted. Use the [sqlite3_total_changes()] function 916** to find the total number of changes including changes caused by triggers. 917** 918** A "row change" is a change to a single row of a single table 919** caused by an INSERT, DELETE, or UPDATE statement. Rows that 920** are changed as side effects of REPLACE constraint resolution, 921** rollback, ABORT processing, DROP TABLE, or by any other 922** mechanisms do not count as direct row changes. 923** 924** A "trigger context" is a scope of execution that begins and 925** ends with the script of a trigger. Most SQL statements are 926** evaluated outside of any trigger. This is the "top level" 927** trigger context. If a trigger fires from the top level, a 928** new trigger context is entered for the duration of that one 929** trigger. Subtriggers create subcontexts for their duration. 930** 931** Calling [sqlite3_exec()] or [sqlite3_step()] recursively does 932** not create a new trigger context. 933** 934** This function returns the number of direct row changes in the 935** most recent INSERT, UPDATE, or DELETE statement within the same 936** trigger context. 937** 938** So when called from the top level, this function returns the 939** number of changes in the most recent INSERT, UPDATE, or DELETE 940** that also occurred at the top level. 941** Within the body of a trigger, the sqlite3_changes() interface 942** can be called to find the number of 943** changes in the most recently completed INSERT, UPDATE, or DELETE 944** statement within the body of the same trigger. 945** However, the number returned does not include in changes 946** caused by subtriggers since they have their own context. 947** 948** SQLite implements the command "DELETE FROM table" without 949** a WHERE clause by dropping and recreating the table. (This is much 950** faster than going through and deleting individual elements from the 951** table.) Because of this optimization, the deletions in 952** "DELETE FROM table" are not row changes and will not be counted 953** by the sqlite3_changes() or [sqlite3_total_changes()] functions. 954** To get an accurate count of the number of rows deleted, use 955** "DELETE FROM table WHERE 1" instead. 956** 957** INVARIANTS: 958** 959** {F12241} The [sqlite3_changes()] function returns the number of 960** row changes caused by the most recent INSERT, UPDATE, 961** or DELETE statement on the same database connection and 962** within the same trigger context, or zero if there have 963** not been any qualifying row changes. 964** 965** LIMITATIONS: 966** 967** {U12252} If a separate thread makes changes on the same database connection 968** while [sqlite3_changes()] is running then the value returned 969** is unpredictable and unmeaningful. 970*/ 971int sqlite3_changes(sqlite3*); 972 973/* 974** CAPI3REF: Total Number Of Rows Modified {F12260} 975*** 976** This function returns the number of row changes caused 977** by INSERT, UPDATE or DELETE statements since the database handle 978** was opened. The count includes all changes from all trigger 979** contexts. But the count does not include changes used to 980** implement REPLACE constraints, do rollbacks or ABORT processing, 981** or DROP table processing. 982** The changes 983** are counted as soon as the statement that makes them is completed 984** (when the statement handle is passed to [sqlite3_reset()] or 985** [sqlite3_finalize()]). 986** 987** SQLite implements the command "DELETE FROM table" without 988** a WHERE clause by dropping and recreating the table. (This is much 989** faster than going 990** through and deleting individual elements from the table.) Because of 991** this optimization, the change count for "DELETE FROM table" will be 992** zero regardless of the number of elements that were originally in the 993** table. To get an accurate count of the number of rows deleted, use 994** "DELETE FROM table WHERE 1" instead. 995** 996** See also the [sqlite3_changes()] interface. 997** 998** INVARIANTS: 999** 1000** {F12261} The [sqlite3_total_changes()] returns the total number 1001** of row changes caused by INSERT, UPDATE, and/or DELETE 1002** statements on the same [database connection], in any 1003** trigger context, since the database connection was 1004** created. 1005** 1006** LIMITATIONS: 1007** 1008** {U12264} If a separate thread makes changes on the same database connection 1009** while [sqlite3_total_changes()] is running then the value 1010** returned is unpredictable and unmeaningful. 1011*/ 1012int sqlite3_total_changes(sqlite3*); 1013 1014/* 1015** CAPI3REF: Interrupt A Long-Running Query {F12270} 1016** 1017** This function causes any pending database operation to abort and 1018** return at its earliest opportunity. This routine is typically 1019** called in response to a user action such as pressing "Cancel" 1020** or Ctrl-C where the user wants a long query operation to halt 1021** immediately. 1022** 1023** It is safe to call this routine from a thread different from the 1024** thread that is currently running the database operation. But it 1025** is not safe to call this routine with a database connection that 1026** is closed or might close before sqlite3_interrupt() returns. 1027** 1028** If an SQL is very nearly finished at the time when sqlite3_interrupt() 1029** is called, then it might not have an opportunity to be interrupted. 1030** It might continue to completion. 1031** An SQL operation that is interrupted will return 1032** [SQLITE_INTERRUPT]. If the interrupted SQL operation is an 1033** INSERT, UPDATE, or DELETE that is inside an explicit transaction, 1034** then the entire transaction will be rolled back automatically. 1035** A call to sqlite3_interrupt() has no effect on SQL statements 1036** that are started after sqlite3_interrupt() returns. 1037** 1038** INVARIANTS: 1039** 1040** {F12271} The [sqlite3_interrupt()] interface will force all running 1041** SQL statements associated with the same database connection 1042** to halt after processing at most one additional row of 1043** data. 1044** 1045** {F12272} Any SQL statement that is interrupted by [sqlite3_interrupt()] 1046** will return [SQLITE_INTERRUPT]. 1047** 1048** LIMITATIONS: 1049** 1050** {U12279} If the database connection closes while [sqlite3_interrupt()] 1051** is running then bad things will likely happen. 1052*/ 1053void sqlite3_interrupt(sqlite3*); 1054 1055/* 1056** CAPI3REF: Determine If An SQL Statement Is Complete {F10510} 1057** 1058** These routines are useful for command-line input to determine if the 1059** currently entered text seems to form complete a SQL statement or 1060** if additional input is needed before sending the text into 1061** SQLite for parsing. These routines return true if the input string 1062** appears to be a complete SQL statement. A statement is judged to be 1063** complete if it ends with a semicolon token and is not a fragment of a 1064** CREATE TRIGGER statement. Semicolons that are embedded within 1065** string literals or quoted identifier names or comments are not 1066** independent tokens (they are part of the token in which they are 1067** embedded) and thus do not count as a statement terminator. 1068** 1069** These routines do not parse the SQL and 1070** so will not detect syntactically incorrect SQL. 1071** 1072** INVARIANTS: 1073** 1074** {F10511} The sqlite3_complete() and sqlite3_complete16() functions 1075** return true (non-zero) if and only if the last 1076** non-whitespace token in their input is a semicolon that 1077** is not in between the BEGIN and END of a CREATE TRIGGER 1078** statement. 1079** 1080** LIMITATIONS: 1081** 1082** {U10512} The input to sqlite3_complete() must be a zero-terminated 1083** UTF-8 string. 1084** 1085** {U10513} The input to sqlite3_complete16() must be a zero-terminated 1086** UTF-16 string in native byte order. 1087*/ 1088int sqlite3_complete(const char *sql); 1089int sqlite3_complete16(const void *sql); 1090 1091/* 1092** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors {F12310} 1093** 1094** This routine identifies a callback function that might be 1095** invoked whenever an attempt is made to open a database table 1096** that another thread or process has locked. 1097** If the busy callback is NULL, then [SQLITE_BUSY] 1098** or [SQLITE_IOERR_BLOCKED] 1099** is returned immediately upon encountering the lock. 1100** If the busy callback is not NULL, then the 1101** callback will be invoked with two arguments. The 1102** first argument to the handler is a copy of the void* pointer which 1103** is the third argument to this routine. The second argument to 1104** the handler is the number of times that the busy handler has 1105** been invoked for this locking event. If the 1106** busy callback returns 0, then no additional attempts are made to 1107** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned. 1108** If the callback returns non-zero, then another attempt 1109** is made to open the database for reading and the cycle repeats. 1110** 1111** The presence of a busy handler does not guarantee that 1112** it will be invoked when there is lock contention. 1113** If SQLite determines that invoking the busy handler could result in 1114** a deadlock, it will go ahead and return [SQLITE_BUSY] or 1115** [SQLITE_IOERR_BLOCKED] instead of invoking the 1116** busy handler. 1117** Consider a scenario where one process is holding a read lock that 1118** it is trying to promote to a reserved lock and 1119** a second process is holding a reserved lock that it is trying 1120** to promote to an exclusive lock. The first process cannot proceed 1121** because it is blocked by the second and the second process cannot 1122** proceed because it is blocked by the first. If both processes 1123** invoke the busy handlers, neither will make any progress. Therefore, 1124** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 1125** will induce the first process to release its read lock and allow 1126** the second process to proceed. 1127** 1128** The default busy callback is NULL. 1129** 1130** The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED] 1131** when SQLite is in the middle of a large transaction where all the 1132** changes will not fit into the in-memory cache. SQLite will 1133** already hold a RESERVED lock on the database file, but it needs 1134** to promote this lock to EXCLUSIVE so that it can spill cache 1135** pages into the database file without harm to concurrent 1136** readers. If it is unable to promote the lock, then the in-memory 1137** cache will be left in an inconsistent state and so the error 1138** code is promoted from the relatively benign [SQLITE_BUSY] to 1139** the more severe [SQLITE_IOERR_BLOCKED]. This error code promotion 1140** forces an automatic rollback of the changes. See the 1141** <a href="http://www.sqlite.org/cvstrac/wiki?p=CorruptionFollowingBusyError"> 1142** CorruptionFollowingBusyError</a> wiki page for a discussion of why 1143** this is important. 1144** 1145** There can only be a single busy handler defined for each database 1146** connection. Setting a new busy handler clears any previous one. 1147** Note that calling [sqlite3_busy_timeout()] will also set or clear 1148** the busy handler. 1149** 1150** INVARIANTS: 1151** 1152** {F12311} The [sqlite3_busy_handler()] function replaces the busy handler 1153** callback in the database connection identified by the 1st 1154** parameter with a new busy handler identified by the 2nd and 3rd 1155** parameters. 1156** 1157** {F12312} The default busy handler for new database connections is NULL. 1158** 1159** {F12314} When two or more database connection share a common cache, 1160** the busy handler for the database connection currently using 1161** the cache is invoked when the cache encounters a lock. 1162** 1163** {F12316} If a busy handler callback returns zero, then the SQLite 1164** interface that provoked the locking event will return 1165** [SQLITE_BUSY]. 1166** 1167** {F12318} SQLite will invokes the busy handler with two argument which 1168** are a copy of the pointer supplied by the 3rd parameter to 1169** [sqlite3_busy_handler()] and a count of the number of prior 1170** invocations of the busy handler for the same locking event. 1171** 1172** LIMITATIONS: 1173** 1174** {U12319} A busy handler should not call close the database connection 1175** or prepared statement that invoked the busy handler. 1176*/ 1177int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*); 1178 1179/* 1180** CAPI3REF: Set A Busy Timeout {F12340} 1181** 1182** This routine sets a [sqlite3_busy_handler | busy handler] 1183** that sleeps for a while when a 1184** table is locked. The handler will sleep multiple times until 1185** at least "ms" milliseconds of sleeping have been done. {F12343} After 1186** "ms" milliseconds of sleeping, the handler returns 0 which 1187** causes [sqlite3_step()] to return [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]. 1188** 1189** Calling this routine with an argument less than or equal to zero 1190** turns off all busy handlers. 1191** 1192** There can only be a single busy handler for a particular database 1193** connection. If another busy handler was defined 1194** (using [sqlite3_busy_handler()]) prior to calling 1195** this routine, that other busy handler is cleared. 1196** 1197** INVARIANTS: 1198** 1199** {F12341} The [sqlite3_busy_timeout()] function overrides any prior 1200** [sqlite3_busy_timeout()] or [sqlite3_busy_handler()] setting 1201** on the same database connection. 1202** 1203** {F12343} If the 2nd parameter to [sqlite3_busy_timeout()] is less than 1204** or equal to zero, then the busy handler is cleared so that 1205** all subsequent locking events immediately return [SQLITE_BUSY]. 1206** 1207** {F12344} If the 2nd parameter to [sqlite3_busy_timeout()] is a positive 1208** number N, then a busy handler is set that repeatedly calls 1209** the xSleep() method in the VFS interface until either the 1210** lock clears or until the cumulative sleep time reported back 1211** by xSleep() exceeds N milliseconds. 1212*/ 1213int sqlite3_busy_timeout(sqlite3*, int ms); 1214 1215/* 1216** CAPI3REF: Convenience Routines For Running Queries {F12370} 1217** 1218** Definition: A <b>result table</b> is memory data structure created by the 1219** [sqlite3_get_table()] interface. A result table records the 1220** complete query results from one or more queries. 1221** 1222** The table conceptually has a number of rows and columns. But 1223** these numbers are not part of the result table itself. These 1224** numbers are obtained separately. Let N be the number of rows 1225** and M be the number of columns. 1226** 1227** A result table is an array of pointers to zero-terminated 1228** UTF-8 strings. There are (N+1)*M elements in the array. 1229** The first M pointers point to zero-terminated strings that 1230** contain the names of the columns. 1231** The remaining entries all point to query results. NULL 1232** values are give a NULL pointer. All other values are in 1233** their UTF-8 zero-terminated string representation as returned by 1234** [sqlite3_column_text()]. 1235** 1236** A result table might consists of one or more memory allocations. 1237** It is not safe to pass a result table directly to [sqlite3_free()]. 1238** A result table should be deallocated using [sqlite3_free_table()]. 1239** 1240** As an example of the result table format, suppose a query result 1241** is as follows: 1242** 1243** <blockquote><pre> 1244** Name | Age 1245** ----------------------- 1246** Alice | 43 1247** Bob | 28 1248** Cindy | 21 1249** </pre></blockquote> 1250** 1251** There are two column (M==2) and three rows (N==3). Thus the 1252** result table has 8 entries. Suppose the result table is stored 1253** in an array names azResult. Then azResult holds this content: 1254** 1255** <blockquote><pre> 1256** azResult[0] = "Name"; 1257** azResult[1] = "Age"; 1258** azResult[2] = "Alice"; 1259** azResult[3] = "43"; 1260** azResult[4] = "Bob"; 1261** azResult[5] = "28"; 1262** azResult[6] = "Cindy"; 1263** azResult[7] = "21"; 1264** </pre></blockquote> 1265** 1266** The sqlite3_get_table() function evaluates one or more 1267** semicolon-separated SQL statements in the zero-terminated UTF-8 1268** string of its 2nd parameter. It returns a result table to the 1269** pointer given in its 3rd parameter. 1270** 1271** After the calling function has finished using the result, it should 1272** pass the pointer to the result table to sqlite3_free_table() in order to 1273** release the memory that was malloc-ed. Because of the way the 1274** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 1275** function must not try to call [sqlite3_free()] directly. Only 1276** [sqlite3_free_table()] is able to release the memory properly and safely. 1277** 1278** The sqlite3_get_table() interface is implemented as a wrapper around 1279** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 1280** to any internal data structures of SQLite. It uses only the public 1281** interface defined here. As a consequence, errors that occur in the 1282** wrapper layer outside of the internal [sqlite3_exec()] call are not 1283** reflected in subsequent calls to [sqlite3_errcode()] or 1284** [sqlite3_errmsg()]. 1285** 1286** INVARIANTS: 1287** 1288** {F12371} If a [sqlite3_get_table()] fails a memory allocation, then 1289** it frees the result table under construction, aborts the 1290** query in process, skips any subsequent queries, sets the 1291** *resultp output pointer to NULL and returns [SQLITE_NOMEM]. 1292** 1293** {F12373} If the ncolumn parameter to [sqlite3_get_table()] is not NULL 1294** then [sqlite3_get_table()] write the number of columns in the 1295** result set of the query into *ncolumn if the query is 1296** successful (if the function returns SQLITE_OK). 1297** 1298** {F12374} If the nrow parameter to [sqlite3_get_table()] is not NULL 1299** then [sqlite3_get_table()] write the number of rows in the 1300** result set of the query into *nrow if the query is 1301** successful (if the function returns SQLITE_OK). 1302** 1303** {F12376} The [sqlite3_get_table()] function sets its *ncolumn value 1304** to the number of columns in the result set of the query in the 1305** sql parameter, or to zero if the query in sql has an empty 1306** result set. 1307*/ 1308int sqlite3_get_table( 1309 sqlite3*, /* An open database */ 1310 const char *sql, /* SQL to be evaluated */ 1311 char ***pResult, /* Results of the query */ 1312 int *nrow, /* Number of result rows written here */ 1313 int *ncolumn, /* Number of result columns written here */ 1314 char **errmsg /* Error msg written here */ 1315); 1316void sqlite3_free_table(char **result); 1317 1318/* 1319** CAPI3REF: Formatted String Printing Functions {F17400} 1320** 1321** These routines are workalikes of the "printf()" family of functions 1322** from the standard C library. 1323** 1324** The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 1325** results into memory obtained from [sqlite3_malloc()]. 1326** The strings returned by these two routines should be 1327** released by [sqlite3_free()]. Both routines return a 1328** NULL pointer if [sqlite3_malloc()] is unable to allocate enough 1329** memory to hold the resulting string. 1330** 1331** In sqlite3_snprintf() routine is similar to "snprintf()" from 1332** the standard C library. The result is written into the 1333** buffer supplied as the second parameter whose size is given by 1334** the first parameter. Note that the order of the 1335** first two parameters is reversed from snprintf(). This is an 1336** historical accident that cannot be fixed without breaking 1337** backwards compatibility. Note also that sqlite3_snprintf() 1338** returns a pointer to its buffer instead of the number of 1339** characters actually written into the buffer. We admit that 1340** the number of characters written would be a more useful return 1341** value but we cannot change the implementation of sqlite3_snprintf() 1342** now without breaking compatibility. 1343** 1344** As long as the buffer size is greater than zero, sqlite3_snprintf() 1345** guarantees that the buffer is always zero-terminated. The first 1346** parameter "n" is the total size of the buffer, including space for 1347** the zero terminator. So the longest string that can be completely 1348** written will be n-1 characters. 1349** 1350** These routines all implement some additional formatting 1351** options that are useful for constructing SQL statements. 1352** All of the usual printf formatting options apply. In addition, there 1353** is are "%q", "%Q", and "%z" options. 1354** 1355** The %q option works like %s in that it substitutes a null-terminated 1356** string from the argument list. But %q also doubles every '\'' character. 1357** %q is designed for use inside a string literal. By doubling each '\'' 1358** character it escapes that character and allows it to be inserted into 1359** the string. 1360** 1361** For example, so some string variable contains text as follows: 1362** 1363** <blockquote><pre> 1364** char *zText = "It's a happy day!"; 1365** </pre></blockquote> 1366** 1367** One can use this text in an SQL statement as follows: 1368** 1369** <blockquote><pre> 1370** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); 1371** sqlite3_exec(db, zSQL, 0, 0, 0); 1372** sqlite3_free(zSQL); 1373** </pre></blockquote> 1374** 1375** Because the %q format string is used, the '\'' character in zText 1376** is escaped and the SQL generated is as follows: 1377** 1378** <blockquote><pre> 1379** INSERT INTO table1 VALUES('It''s a happy day!') 1380** </pre></blockquote> 1381** 1382** This is correct. Had we used %s instead of %q, the generated SQL 1383** would have looked like this: 1384** 1385** <blockquote><pre> 1386** INSERT INTO table1 VALUES('It's a happy day!'); 1387** </pre></blockquote> 1388** 1389** This second example is an SQL syntax error. As a general rule you 1390** should always use %q instead of %s when inserting text into a string 1391** literal. 1392** 1393** The %Q option works like %q except it also adds single quotes around 1394** the outside of the total string. Or if the parameter in the argument 1395** list is a NULL pointer, %Q substitutes the text "NULL" (without single 1396** quotes) in place of the %Q option. {END} So, for example, one could say: 1397** 1398** <blockquote><pre> 1399** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); 1400** sqlite3_exec(db, zSQL, 0, 0, 0); 1401** sqlite3_free(zSQL); 1402** </pre></blockquote> 1403** 1404** The code above will render a correct SQL statement in the zSQL 1405** variable even if the zText variable is a NULL pointer. 1406** 1407** The "%z" formatting option works exactly like "%s" with the 1408** addition that after the string has been read and copied into 1409** the result, [sqlite3_free()] is called on the input string. {END} 1410** 1411** INVARIANTS: 1412** 1413** {F17403} The [sqlite3_mprintf()] and [sqlite3_vmprintf()] interfaces 1414** return either pointers to zero-terminated UTF-8 strings held in 1415** memory obtained from [sqlite3_malloc()] or NULL pointers if 1416** a call to [sqlite3_malloc()] fails. 1417** 1418** {F17406} The [sqlite3_snprintf()] interface writes a zero-terminated 1419** UTF-8 string into the buffer pointed to by the second parameter 1420** provided that the first parameter is greater than zero. 1421** 1422** {F17407} The [sqlite3_snprintf()] interface does not writes slots of 1423** its output buffer (the second parameter) outside the range 1424** of 0 through N-1 (where N is the first parameter) 1425** regardless of the length of the string 1426** requested by the format specification. 1427** 1428*/ 1429char *sqlite3_mprintf(const char*,...); 1430char *sqlite3_vmprintf(const char*, va_list); 1431char *sqlite3_snprintf(int,char*,const char*, ...); 1432 1433/* 1434** CAPI3REF: Memory Allocation Subsystem {F17300} 1435** 1436** The SQLite core uses these three routines for all of its own 1437** internal memory allocation needs. "Core" in the previous sentence 1438** does not include operating-system specific VFS implementation. The 1439** windows VFS uses native malloc and free for some operations. 1440** 1441** The sqlite3_malloc() routine returns a pointer to a block 1442** of memory at least N bytes in length, where N is the parameter. 1443** If sqlite3_malloc() is unable to obtain sufficient free 1444** memory, it returns a NULL pointer. If the parameter N to 1445** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 1446** a NULL pointer. 1447** 1448** Calling sqlite3_free() with a pointer previously returned 1449** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 1450** that it might be reused. The sqlite3_free() routine is 1451** a no-op if is called with a NULL pointer. Passing a NULL pointer 1452** to sqlite3_free() is harmless. After being freed, memory 1453** should neither be read nor written. Even reading previously freed 1454** memory might result in a segmentation fault or other severe error. 1455** Memory corruption, a segmentation fault, or other severe error 1456** might result if sqlite3_free() is called with a non-NULL pointer that 1457** was not obtained from sqlite3_malloc() or sqlite3_free(). 1458** 1459** The sqlite3_realloc() interface attempts to resize a 1460** prior memory allocation to be at least N bytes, where N is the 1461** second parameter. The memory allocation to be resized is the first 1462** parameter. If the first parameter to sqlite3_realloc() 1463** is a NULL pointer then its behavior is identical to calling 1464** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc(). 1465** If the second parameter to sqlite3_realloc() is zero or 1466** negative then the behavior is exactly the same as calling 1467** sqlite3_free(P) where P is the first parameter to sqlite3_realloc(). 1468** Sqlite3_realloc() returns a pointer to a memory allocation 1469** of at least N bytes in size or NULL if sufficient memory is unavailable. 1470** If M is the size of the prior allocation, then min(N,M) bytes 1471** of the prior allocation are copied into the beginning of buffer returned 1472** by sqlite3_realloc() and the prior allocation is freed. 1473** If sqlite3_realloc() returns NULL, then the prior allocation 1474** is not freed. 1475** 1476** The memory returned by sqlite3_malloc() and sqlite3_realloc() 1477** is always aligned to at least an 8 byte boundary. {END} 1478** 1479** The default implementation 1480** of the memory allocation subsystem uses the malloc(), realloc() 1481** and free() provided by the standard C library. {F17382} However, if 1482** SQLite is compiled with the following C preprocessor macro 1483** 1484** <blockquote> SQLITE_MEMORY_SIZE=<i>NNN</i> </blockquote> 1485** 1486** where <i>NNN</i> is an integer, then SQLite create a static 1487** array of at least <i>NNN</i> bytes in size and use that array 1488** for all of its dynamic memory allocation needs. {END} Additional 1489** memory allocator options may be added in future releases. 1490** 1491** In SQLite version 3.5.0 and 3.5.1, it was possible to define 1492** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 1493** implementation of these routines to be omitted. That capability 1494** is no longer provided. Only built-in memory allocators can be 1495** used. 1496** 1497** The windows OS interface layer calls 1498** the system malloc() and free() directly when converting 1499** filenames between the UTF-8 encoding used by SQLite 1500** and whatever filename encoding is used by the particular windows 1501** installation. Memory allocation errors are detected, but 1502** they are reported back as [SQLITE_CANTOPEN] or 1503** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 1504** 1505** INVARIANTS: 1506** 1507** {F17303} The [sqlite3_malloc(N)] interface returns either a pointer to 1508** newly checked-out block of at least N bytes of memory 1509** that is 8-byte aligned, 1510** or it returns NULL if it is unable to fulfill the request. 1511** 1512** {F17304} The [sqlite3_malloc(N)] interface returns a NULL pointer if 1513** N is less than or equal to zero. 1514** 1515** {F17305} The [sqlite3_free(P)] interface releases memory previously 1516** returned from [sqlite3_malloc()] or [sqlite3_realloc()], 1517** making it available for reuse. 1518** 1519** {F17306} A call to [sqlite3_free(NULL)] is a harmless no-op. 1520** 1521** {F17310} A call to [sqlite3_realloc(0,N)] is equivalent to a call 1522** to [sqlite3_malloc(N)]. 1523** 1524** {F17312} A call to [sqlite3_realloc(P,0)] is equivalent to a call 1525** to [sqlite3_free(P)]. 1526** 1527** {F17315} The SQLite core uses [sqlite3_malloc()], [sqlite3_realloc()], 1528** and [sqlite3_free()] for all of its memory allocation and 1529** deallocation needs. 1530** 1531** {F17318} The [sqlite3_realloc(P,N)] interface returns either a pointer 1532** to a block of checked-out memory of at least N bytes in size 1533** that is 8-byte aligned, or a NULL pointer. 1534** 1535** {F17321} When [sqlite3_realloc(P,N)] returns a non-NULL pointer, it first 1536** copies the first K bytes of content from P into the newly allocated 1537** where K is the lessor of N and the size of the buffer P. 1538** 1539** {F17322} When [sqlite3_realloc(P,N)] returns a non-NULL pointer, it first 1540** releases the buffer P. 1541** 1542** {F17323} When [sqlite3_realloc(P,N)] returns NULL, the buffer P is 1543** not modified or released. 1544** 1545** LIMITATIONS: 1546** 1547** {U17350} The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 1548** must be either NULL or else a pointer obtained from a prior 1549** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that has 1550** not been released. 1551** 1552** {U17351} The application must not read or write any part of 1553** a block of memory after it has been released using 1554** [sqlite3_free()] or [sqlite3_realloc()]. 1555** 1556*/ 1557void *sqlite3_malloc(int); 1558void *sqlite3_realloc(void*, int); 1559void sqlite3_free(void*); 1560 1561/* 1562** CAPI3REF: Memory Allocator Statistics {F17370} 1563** 1564** SQLite provides these two interfaces for reporting on the status 1565** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 1566** the memory allocation subsystem included within the SQLite. 1567** 1568** INVARIANTS: 1569** 1570** {F17371} The [sqlite3_memory_used()] routine returns the 1571** number of bytes of memory currently outstanding 1572** (malloced but not freed). 1573** 1574** {F17373} The [sqlite3_memory_highwater()] routine returns the maximum 1575** value of [sqlite3_memory_used()] 1576** since the highwater mark was last reset. 1577** 1578** {F17374} The values returned by [sqlite3_memory_used()] and 1579** [sqlite3_memory_highwater()] include any overhead 1580** added by SQLite in its implementation of [sqlite3_malloc()], 1581** but not overhead added by the any underlying system library 1582** routines that [sqlite3_malloc()] may call. 1583** 1584** {F17375} The memory highwater mark is reset to the current value of 1585** [sqlite3_memory_used()] if and only if the parameter to 1586** [sqlite3_memory_highwater()] is true. The value returned 1587** by [sqlite3_memory_highwater(1)] is the highwater mark 1588** prior to the reset. 1589*/ 1590sqlite3_int64 sqlite3_memory_used(void); 1591sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 1592 1593/* 1594** CAPI3REF: Pseudo-Random Number Generator {F17390} 1595** 1596** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 1597** select random ROWIDs when inserting new records into a table that 1598** already uses the largest possible ROWID. The PRNG is also used for 1599** the build-in random() and randomblob() SQL functions. This interface allows 1600** appliations to access the same PRNG for other purposes. 1601** 1602** A call to this routine stores N bytes of randomness into buffer P. 1603** 1604** The first time this routine is invoked (either internally or by 1605** the application) the PRNG is seeded using randomness obtained 1606** from the xRandomness method of the default [sqlite3_vfs] object. 1607** On all subsequent invocations, the pseudo-randomness is generated 1608** internally and without recourse to the [sqlite3_vfs] xRandomness 1609** method. 1610** 1611** INVARIANTS: 1612** 1613** {F17392} The [sqlite3_randomness(N,P)] interface writes N bytes of 1614** high-quality pseudo-randomness into buffer P. 1615*/ 1616void sqlite3_randomness(int N, void *P); 1617 1618/* 1619** CAPI3REF: Compile-Time Authorization Callbacks {F12500} 1620** 1621** This routine registers a authorizer callback with a particular 1622** [database connection], supplied in the first argument. 1623** The authorizer callback is invoked as SQL statements are being compiled 1624** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 1625** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. At various 1626** points during the compilation process, as logic is being created 1627** to perform various actions, the authorizer callback is invoked to 1628** see if those actions are allowed. The authorizer callback should 1629** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 1630** specific action but allow the SQL statement to continue to be 1631** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 1632** rejected with an error. If the authorizer callback returns 1633** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 1634** then [sqlite3_prepare_v2()] or equivalent call that triggered 1635** the authorizer will fail with an error message. 1636** 1637** When the callback returns [SQLITE_OK], that means the operation 1638** requested is ok. When the callback returns [SQLITE_DENY], the 1639** [sqlite3_prepare_v2()] or equivalent call that triggered the 1640** authorizer will fail with an error message explaining that 1641** access is denied. If the authorizer code is [SQLITE_READ] 1642** and the callback returns [SQLITE_IGNORE] then the 1643** [prepared statement] statement is constructed to substitute 1644** a NULL value in place of the table column that would have 1645** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 1646** return can be used to deny an untrusted user access to individual 1647** columns of a table. 1648** 1649** The first parameter to the authorizer callback is a copy of 1650** the third parameter to the sqlite3_set_authorizer() interface. 1651** The second parameter to the callback is an integer 1652** [SQLITE_COPY | action code] that specifies the particular action 1653** to be authorized. The third through sixth 1654** parameters to the callback are zero-terminated strings that contain 1655** additional details about the action to be authorized. 1656** 1657** An authorizer is used when [sqlite3_prepare | preparing] 1658** SQL statements from an untrusted 1659** source, to ensure that the SQL statements do not try to access data 1660** that they are not allowed to see, or that they do not try to 1661** execute malicious statements that damage the database. For 1662** example, an application may allow a user to enter arbitrary 1663** SQL queries for evaluation by a database. But the application does 1664** not want the user to be able to make arbitrary changes to the 1665** database. An authorizer could then be put in place while the 1666** user-entered SQL is being [sqlite3_prepare | prepared] that 1667** disallows everything except [SELECT] statements. 1668** 1669** Applications that need to process SQL from untrusted sources 1670** might also consider lowering resource limits using [sqlite3_limit()] 1671** and limiting database size using the [max_page_count] [PRAGMA] 1672** in addition to using an authorizer. 1673** 1674** Only a single authorizer can be in place on a database connection 1675** at a time. Each call to sqlite3_set_authorizer overrides the 1676** previous call. Disable the authorizer by installing a NULL callback. 1677** The authorizer is disabled by default. 1678** 1679** Note that the authorizer callback is invoked only during 1680** [sqlite3_prepare()] or its variants. Authorization is not 1681** performed during statement evaluation in [sqlite3_step()]. 1682** 1683** INVARIANTS: 1684** 1685** {F12501} The [sqlite3_set_authorizer(D,...)] interface registers a 1686** authorizer callback with database connection D. 1687** 1688** {F12502} The authorizer callback is invoked as SQL statements are 1689** being compiled 1690** 1691** {F12503} If the authorizer callback returns any value other than 1692** [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] then 1693** the [sqlite3_prepare_v2()] or equivalent call that caused 1694** the authorizer callback to run shall fail with an 1695** [SQLITE_ERROR] error code and an appropriate error message. 1696** 1697** {F12504} When the authorizer callback returns [SQLITE_OK], the operation 1698** described is coded normally. 1699** 1700** {F12505} When the authorizer callback returns [SQLITE_DENY], the 1701** [sqlite3_prepare_v2()] or equivalent call that caused the 1702** authorizer callback to run shall fail 1703** with an [SQLITE_ERROR] error code and an error message 1704** explaining that access is denied. 1705** 1706** {F12506} If the authorizer code (the 2nd parameter to the authorizer 1707** callback) is [SQLITE_READ] and the authorizer callback returns 1708** [SQLITE_IGNORE] then the prepared statement is constructed to 1709** insert a NULL value in place of the table column that would have 1710** been read if [SQLITE_OK] had been returned. 1711** 1712** {F12507} If the authorizer code (the 2nd parameter to the authorizer 1713** callback) is anything other than [SQLITE_READ], then 1714** a return of [SQLITE_IGNORE] has the same effect as [SQLITE_DENY]. 1715** 1716** {F12510} The first parameter to the authorizer callback is a copy of 1717** the third parameter to the [sqlite3_set_authorizer()] interface. 1718** 1719** {F12511} The second parameter to the callback is an integer 1720** [SQLITE_COPY | action code] that specifies the particular action 1721** to be authorized. 1722** 1723** {F12512} The third through sixth parameters to the callback are 1724** zero-terminated strings that contain 1725** additional details about the action to be authorized. 1726** 1727** {F12520} Each call to [sqlite3_set_authorizer()] overrides the 1728** any previously installed authorizer. 1729** 1730** {F12521} A NULL authorizer means that no authorization 1731** callback is invoked. 1732** 1733** {F12522} The default authorizer is NULL. 1734*/ 1735int sqlite3_set_authorizer( 1736 sqlite3*, 1737 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 1738 void *pUserData 1739); 1740 1741/* 1742** CAPI3REF: Authorizer Return Codes {F12590} 1743** 1744** The [sqlite3_set_authorizer | authorizer callback function] must 1745** return either [SQLITE_OK] or one of these two constants in order 1746** to signal SQLite whether or not the action is permitted. See the 1747** [sqlite3_set_authorizer | authorizer documentation] for additional 1748** information. 1749*/ 1750#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 1751#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 1752 1753/* 1754** CAPI3REF: Authorizer Action Codes {F12550} 1755** 1756** The [sqlite3_set_authorizer()] interface registers a callback function 1757** that is invoked to authorizer certain SQL statement actions. The 1758** second parameter to the callback is an integer code that specifies 1759** what action is being authorized. These are the integer action codes that 1760** the authorizer callback may be passed. 1761** 1762** These action code values signify what kind of operation is to be 1763** authorized. The 3rd and 4th parameters to the authorization 1764** callback function will be parameters or NULL depending on which of these 1765** codes is used as the second parameter. The 5th parameter to the 1766** authorizer callback is the name of the database ("main", "temp", 1767** etc.) if applicable. The 6th parameter to the authorizer callback 1768** is the name of the inner-most trigger or view that is responsible for 1769** the access attempt or NULL if this access attempt is directly from 1770** top-level SQL code. 1771** 1772** INVARIANTS: 1773** 1774** {F12551} The second parameter to an 1775** [sqlite3_set_authorizer | authorizer callback is always an integer 1776** [SQLITE_COPY | authorizer code] that specifies what action 1777** is being authorized. 1778** 1779** {F12552} The 3rd and 4th parameters to the 1780** [sqlite3_set_authorizer | authorization callback function] 1781** will be parameters or NULL depending on which 1782** [SQLITE_COPY | authorizer code] is used as the second parameter. 1783** 1784** {F12553} The 5th parameter to the 1785** [sqlite3_set_authorizer | authorizer callback] is the name 1786** of the database (example: "main", "temp", etc.) if applicable. 1787** 1788** {F12554} The 6th parameter to the 1789** [sqlite3_set_authorizer | authorizer callback] is the name 1790** of the inner-most trigger or view that is responsible for 1791** the access attempt or NULL if this access attempt is directly from 1792** top-level SQL code. 1793*/ 1794/******************************************* 3rd ************ 4th ***********/ 1795#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 1796#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 1797#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 1798#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 1799#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 1800#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 1801#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 1802#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 1803#define SQLITE_DELETE 9 /* Table Name NULL */ 1804#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 1805#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 1806#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 1807#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 1808#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 1809#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 1810#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 1811#define SQLITE_DROP_VIEW 17 /* View Name NULL */ 1812#define SQLITE_INSERT 18 /* Table Name NULL */ 1813#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 1814#define SQLITE_READ 20 /* Table Name Column Name */ 1815#define SQLITE_SELECT 21 /* NULL NULL */ 1816#define SQLITE_TRANSACTION 22 /* NULL NULL */ 1817#define SQLITE_UPDATE 23 /* Table Name Column Name */ 1818#define SQLITE_ATTACH 24 /* Filename NULL */ 1819#define SQLITE_DETACH 25 /* Database Name NULL */ 1820#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 1821#define SQLITE_REINDEX 27 /* Index Name NULL */ 1822#define SQLITE_ANALYZE 28 /* Table Name NULL */ 1823#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 1824#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 1825#define SQLITE_FUNCTION 31 /* Function Name NULL */ 1826#define SQLITE_COPY 0 /* No longer used */ 1827 1828/* 1829** CAPI3REF: Tracing And Profiling Functions {F12280} 1830** 1831** These routines register callback functions that can be used for 1832** tracing and profiling the execution of SQL statements. 1833** 1834** The callback function registered by sqlite3_trace() is invoked at 1835** various times when an SQL statement is being run by [sqlite3_step()]. 1836** The callback returns a UTF-8 rendering of the SQL statement text 1837** as the statement first begins executing. Additional callbacks occur 1838** as each triggersubprogram is entered. The callbacks for triggers 1839** contain a UTF-8 SQL comment that identifies the trigger. 1840** 1841** The callback function registered by sqlite3_profile() is invoked 1842** as each SQL statement finishes. The profile callback contains 1843** the original statement text and an estimate of wall-clock time 1844** of how long that statement took to run. 1845** 1846** The sqlite3_profile() API is currently considered experimental and 1847** is subject to change or removal in a future release. 1848** 1849** The trigger reporting feature of the trace callback is considered 1850** experimental and is subject to change or removal in future releases. 1851** Future versions of SQLite might also add new trace callback 1852** invocations. 1853** 1854** INVARIANTS: 1855** 1856** {F12281} The callback function registered by [sqlite3_trace()] is 1857** whenever an SQL statement first begins to execute and 1858** whenever a trigger subprogram first begins to run. 1859** 1860** {F12282} Each call to [sqlite3_trace()] overrides the previously 1861** registered trace callback. 1862** 1863** {F12283} A NULL trace callback disables tracing. 1864** 1865** {F12284} The first argument to the trace callback is a copy of 1866** the pointer which was the 3rd argument to [sqlite3_trace()]. 1867** 1868** {F12285} The second argument to the trace callback is a 1869** zero-terminated UTF8 string containing the original text 1870** of the SQL statement as it was passed into [sqlite3_prepare_v2()] 1871** or the equivalent, or an SQL comment indicating the beginning 1872** of a trigger subprogram. 1873** 1874** {F12287} The callback function registered by [sqlite3_profile()] is invoked 1875** as each SQL statement finishes. 1876** 1877** {F12288} The first parameter to the profile callback is a copy of 1878** the 3rd parameter to [sqlite3_profile()]. 1879** 1880** {F12289} The second parameter to the profile callback is a 1881** zero-terminated UTF-8 string that contains the complete text of 1882** the SQL statement as it was processed by [sqlite3_prepare_v2()] 1883** or the equivalent. 1884** 1885** {F12290} The third parameter to the profile callback is an estimate 1886** of the number of nanoseconds of wall-clock time required to 1887** run the SQL statement from start to finish. 1888*/ 1889void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*); 1890void *sqlite3_profile(sqlite3*, 1891 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 1892 1893/* 1894** CAPI3REF: Query Progress Callbacks {F12910} 1895** 1896** This routine configures a callback function - the 1897** progress callback - that is invoked periodically during long 1898** running calls to [sqlite3_exec()], [sqlite3_step()] and 1899** [sqlite3_get_table()]. An example use for this 1900** interface is to keep a GUI updated during a large query. 1901** 1902** If the progress callback returns non-zero, the opertion is 1903** interrupted. This feature can be used to implement a 1904** "Cancel" button on a GUI dialog box. 1905** 1906** INVARIANTS: 1907** 1908** {F12911} The callback function registered by [sqlite3_progress_handler()] 1909** is invoked periodically during long running calls to 1910** [sqlite3_step()]. 1911** 1912** {F12912} The progress callback is invoked once for every N virtual 1913** machine opcodes, where N is the second argument to 1914** the [sqlite3_progress_handler()] call that registered 1915** the callback. <todo>What if N is less than 1?</todo> 1916** 1917** {F12913} The progress callback itself is identified by the third 1918** argument to [sqlite3_progress_handler()]. 1919** 1920** {F12914} The fourth argument [sqlite3_progress_handler()] is a 1921*** void pointer passed to the progress callback 1922** function each time it is invoked. 1923** 1924** {F12915} If a call to [sqlite3_step()] results in fewer than 1925** N opcodes being executed, 1926** then the progress callback is never invoked. {END} 1927** 1928** {F12916} Every call to [sqlite3_progress_handler()] 1929** overwrites any previously registere progress handler. 1930** 1931** {F12917} If the progress handler callback is NULL then no progress 1932** handler is invoked. 1933** 1934** {F12918} If the progress callback returns a result other than 0, then 1935** the behavior is a if [sqlite3_interrupt()] had been called. 1936*/ 1937void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 1938 1939/* 1940** CAPI3REF: Opening A New Database Connection {F12700} 1941** 1942** These routines open an SQLite database file whose name 1943** is given by the filename argument. 1944** The filename argument is interpreted as UTF-8 1945** for [sqlite3_open()] and [sqlite3_open_v2()] and as UTF-16 1946** in the native byte order for [sqlite3_open16()]. 1947** An [sqlite3*] handle is usually returned in *ppDb, even 1948** if an error occurs. The only exception is if SQLite is unable 1949** to allocate memory to hold the [sqlite3] object, a NULL will 1950** be written into *ppDb instead of a pointer to the [sqlite3] object. 1951** If the database is opened (and/or created) 1952** successfully, then [SQLITE_OK] is returned. Otherwise an 1953** error code is returned. The 1954** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 1955** an English language description of the error. 1956** 1957** The default encoding for the database will be UTF-8 if 1958** [sqlite3_open()] or [sqlite3_open_v2()] is called and 1959** UTF-16 in the native byte order if [sqlite3_open16()] is used. 1960** 1961** Whether or not an error occurs when it is opened, resources 1962** associated with the [sqlite3*] handle should be released by passing it 1963** to [sqlite3_close()] when it is no longer required. 1964** 1965** The [sqlite3_open_v2()] interface works like [sqlite3_open()] 1966** except that it acccepts two additional parameters for additional control 1967** over the new database connection. The flags parameter can be 1968** one of: 1969** 1970** <ol> 1971** <li> [SQLITE_OPEN_READONLY] 1972** <li> [SQLITE_OPEN_READWRITE] 1973** <li> [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE] 1974** </ol> 1975** 1976** The first value opens the database read-only. 1977** If the database does not previously exist, an error is returned. 1978** The second option opens 1979** the database for reading and writing if possible, or reading only if 1980** if the file is write protected. In either case the database 1981** must already exist or an error is returned. The third option 1982** opens the database for reading and writing and creates it if it does 1983** not already exist. 1984** The third options is behavior that is always used for [sqlite3_open()] 1985** and [sqlite3_open16()]. 1986** 1987** If the 3rd parameter to [sqlite3_open_v2()] is not one of the 1988** combinations shown above then the behavior is undefined. 1989** 1990** If the filename is ":memory:", then an private 1991** in-memory database is created for the connection. This in-memory 1992** database will vanish when the database connection is closed. Future 1993** version of SQLite might make use of additional special filenames 1994** that begin with the ":" character. It is recommended that 1995** when a database filename really does begin with 1996** ":" that you prefix the filename with a pathname like "./" to 1997** avoid ambiguity. 1998** 1999** If the filename is an empty string, then a private temporary 2000** on-disk database will be created. This private database will be 2001** automatically deleted as soon as the database connection is closed. 2002** 2003** The fourth parameter to sqlite3_open_v2() is the name of the 2004** [sqlite3_vfs] object that defines the operating system 2005** interface that the new database connection should use. If the 2006** fourth parameter is a NULL pointer then the default [sqlite3_vfs] 2007** object is used. 2008** 2009** <b>Note to windows users:</b> The encoding used for the filename argument 2010** of [sqlite3_open()] and [sqlite3_open_v2()] must be UTF-8, not whatever 2011** codepage is currently defined. Filenames containing international 2012** characters must be converted to UTF-8 prior to passing them into 2013** [sqlite3_open()] or [sqlite3_open_v2()]. 2014** 2015** INVARIANTS: 2016** 2017** {F12701} The [sqlite3_open()], [sqlite3_open16()], and 2018** [sqlite3_open_v2()] interfaces create a new 2019** [database connection] associated with 2020** the database file given in their first parameter. 2021** 2022** {F12702} The filename argument is interpreted as UTF-8 2023** for [sqlite3_open()] and [sqlite3_open_v2()] and as UTF-16 2024** in the native byte order for [sqlite3_open16()]. 2025** 2026** {F12703} A successful invocation of [sqlite3_open()], [sqlite3_open16()], 2027** or [sqlite3_open_v2()] writes a pointer to a new 2028** [database connection] into *ppDb. 2029** 2030** {F12704} The [sqlite3_open()], [sqlite3_open16()], and 2031** [sqlite3_open_v2()] interfaces return [SQLITE_OK] upon success, 2032** or an appropriate [error code] on failure. 2033** 2034** {F12706} The default text encoding for a new database created using 2035** [sqlite3_open()] or [sqlite3_open_v2()] will be UTF-8. 2036** 2037** {F12707} The default text encoding for a new database created using 2038** [sqlite3_open16()] will be UTF-16. 2039** 2040** {F12709} The [sqlite3_open(F,D)] interface is equivalent to 2041** [sqlite3_open_v2(F,D,G,0)] where the G parameter is 2042** [SQLITE_OPEN_READWRITE]|[SQLITE_OPEN_CREATE]. 2043** 2044** {F12711} If the G parameter to [sqlite3_open_v2(F,D,G,V)] contains the 2045** bit value [SQLITE_OPEN_READONLY] then the database is opened 2046** for reading only. 2047** 2048** {F12712} If the G parameter to [sqlite3_open_v2(F,D,G,V)] contains the 2049** bit value [SQLITE_OPEN_READWRITE] then the database is opened 2050** reading and writing if possible, or for reading only if the 2051** file is write protected by the operating system. 2052** 2053** {F12713} If the G parameter to [sqlite3_open(v2(F,D,G,V)] omits the 2054** bit value [SQLITE_OPEN_CREATE] and the database does not 2055** previously exist, an error is returned. 2056** 2057** {F12714} If the G parameter to [sqlite3_open(v2(F,D,G,V)] contains the 2058** bit value [SQLITE_OPEN_CREATE] and the database does not 2059** previously exist, then an attempt is made to create and 2060** initialize the database. 2061** 2062** {F12717} If the filename argument to [sqlite3_open()], [sqlite3_open16()], 2063** or [sqlite3_open_v2()] is ":memory:", then an private, 2064** ephemeral, in-memory database is created for the connection. 2065** <todo>Is SQLITE_OPEN_CREATE|SQLITE_OPEN_READWRITE required 2066** in sqlite3_open_v2()?</todo> 2067** 2068** {F12719} If the filename is NULL or an empty string, then a private, 2069** ephermeral on-disk database will be created. 2070** <todo>Is SQLITE_OPEN_CREATE|SQLITE_OPEN_READWRITE required 2071** in sqlite3_open_v2()?</todo> 2072** 2073** {F12721} The [database connection] created by 2074** [sqlite3_open_v2(F,D,G,V)] will use the 2075** [sqlite3_vfs] object identified by the V parameter, or 2076** the default [sqlite3_vfs] object is V is a NULL pointer. 2077*/ 2078int sqlite3_open( 2079 const char *filename, /* Database filename (UTF-8) */ 2080 sqlite3 **ppDb /* OUT: SQLite db handle */ 2081); 2082int sqlite3_open16( 2083 const void *filename, /* Database filename (UTF-16) */ 2084 sqlite3 **ppDb /* OUT: SQLite db handle */ 2085); 2086int sqlite3_open_v2( 2087 const char *filename, /* Database filename (UTF-8) */ 2088 sqlite3 **ppDb, /* OUT: SQLite db handle */ 2089 int flags, /* Flags */ 2090 const char *zVfs /* Name of VFS module to use */ 2091); 2092 2093/* 2094** CAPI3REF: Error Codes And Messages {F12800} 2095** 2096** The sqlite3_errcode() interface returns the numeric 2097** [SQLITE_OK | result code] or [SQLITE_IOERR_READ | extended result code] 2098** for the most recent failed sqlite3_* API call associated 2099** with [sqlite3] handle 'db'. If a prior API call failed but the 2100** most recent API call succeeded, the return value from sqlite3_errcode() 2101** is undefined. 2102** 2103** The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 2104** text that describes the error, as either UTF8 or UTF16 respectively. 2105** Memory to hold the error message string is managed internally. 2106** The application does not need to worry with freeing the result. 2107** However, the error string might be overwritten or deallocated by 2108** subsequent calls to other SQLite interface functions. 2109** 2110** INVARIANTS: 2111** 2112** {F12801} The [sqlite3_errcode(D)] interface returns the numeric 2113** [SQLITE_OK | result code] or 2114** [SQLITE_IOERR_READ | extended result code] 2115** for the most recently failed interface call associated 2116** with [database connection] D. 2117** 2118** {F12803} The [sqlite3_errmsg(D)] and [sqlite3_errmsg16(D)] 2119** interfaces return English-language text that describes 2120** the error in the mostly recently failed interface call, 2121** encoded as either UTF8 or UTF16 respectively. 2122** 2123** {F12807} The strings returned by [sqlite3_errmsg()] and [sqlite3_errmsg16()] 2124** are valid until the next SQLite interface call. 2125** 2126** {F12808} Calls to API routines that do not return an error code 2127** (example: [sqlite3_data_count()]) do not 2128** change the error code or message returned by 2129** [sqlite3_errcode()], [sqlite3_errmsg()], or [sqlite3_errmsg16()]. 2130** 2131** {F12809} Interfaces that are not associated with a specific 2132** [database connection] (examples: 2133** [sqlite3_mprintf()] or [sqlite3_enable_shared_cache()] 2134** do not change the values returned by 2135** [sqlite3_errcode()], [sqlite3_errmsg()], or [sqlite3_errmsg16()]. 2136*/ 2137int sqlite3_errcode(sqlite3 *db); 2138const char *sqlite3_errmsg(sqlite3*); 2139const void *sqlite3_errmsg16(sqlite3*); 2140 2141/* 2142** CAPI3REF: SQL Statement Object {F13000} 2143** KEYWORDS: {prepared statement} {prepared statements} 2144** 2145** An instance of this object represent single SQL statements. This 2146** object is variously known as a "prepared statement" or a 2147** "compiled SQL statement" or simply as a "statement". 2148** 2149** The life of a statement object goes something like this: 2150** 2151** <ol> 2152** <li> Create the object using [sqlite3_prepare_v2()] or a related 2153** function. 2154** <li> Bind values to host parameters using 2155** [sqlite3_bind_blob | sqlite3_bind_* interfaces]. 2156** <li> Run the SQL by calling [sqlite3_step()] one or more times. 2157** <li> Reset the statement using [sqlite3_reset()] then go back 2158** to step 2. Do this zero or more times. 2159** <li> Destroy the object using [sqlite3_finalize()]. 2160** </ol> 2161** 2162** Refer to documentation on individual methods above for additional 2163** information. 2164*/ 2165typedef struct sqlite3_stmt sqlite3_stmt; 2166 2167/* 2168** CAPI3REF: Run-time Limits {F12760} 2169** 2170** This interface allows the size of various constructs to be limited 2171** on a connection by connection basis. The first parameter is the 2172** [database connection] whose limit is to be set or queried. The 2173** second parameter is one of the [limit categories] that define a 2174** class of constructs to be size limited. The third parameter is the 2175** new limit for that construct. The function returns the old limit. 2176** 2177** If the new limit is a negative number, the limit is unchanged. 2178** For the limit category of SQLITE_LIMIT_XYZ there is a hard upper 2179** bound set by a compile-time C-preprocess macro named SQLITE_MAX_XYZ. 2180** (The "_LIMIT_" in the name is changed to "_MAX_".) 2181** Attempts to increase a limit above its hard upper bound are 2182** silently truncated to the hard upper limit. 2183** 2184** Run time limits are intended for use in applications that manage 2185** both their own internal database and also databases that are controlled 2186** by untrusted external sources. An example application might be a 2187** webbrowser that has its own databases for storing history and 2188** separate databases controlled by javascript applications downloaded 2189** off the internet. The internal databases can be given the 2190** large, default limits. Databases managed by external sources can 2191** be given much smaller limits designed to prevent a denial of service 2192** attach. Developers might also want to use the [sqlite3_set_authorizer()] 2193** interface to further control untrusted SQL. The size of the database 2194** created by an untrusted script can be contained using the 2195** [max_page_count] [PRAGMA]. 2196** 2197** This interface is currently considered experimental and is subject 2198** to change or removal without prior notice. 2199** 2200** INVARIANTS: 2201** 2202** {F12762} A successful call to [sqlite3_limit(D,C,V)] where V is 2203** positive changes the 2204** limit on the size of construct C in [database connection] D 2205** to the lessor of V and the hard upper bound on the size 2206** of C that is set at compile-time. 2207** 2208** {F12766} A successful call to [sqlite3_limit(D,C,V)] where V is negative 2209** leaves the state of [database connection] D unchanged. 2210** 2211** {F12769} A successful call to [sqlite3_limit(D,C,V)] returns the 2212** value of the limit on the size of construct C in 2213** in [database connection] D as it was prior to the call. 2214*/ 2215int sqlite3_limit(sqlite3*, int id, int newVal); 2216 2217/* 2218** CAPI3REF: Run-Time Limit Categories {F12790} 2219** KEYWORDS: {limit category} {limit categories} 2220** 2221** These constants define various aspects of a [database connection] 2222** that can be limited in size by calls to [sqlite3_limit()]. 2223** The meanings of the various limits are as follows: 2224** 2225** <dl> 2226** <dt>SQLITE_LIMIT_LENGTH</dt> 2227** <dd>The maximum size of any 2228** string or blob or table row.<dd> 2229** 2230** <dt>SQLITE_LIMIT_SQL_LENGTH</dt> 2231** <dd>The maximum length of an SQL statement.</dd> 2232** 2233** <dt>SQLITE_LIMIT_COLUMN</dt> 2234** <dd>The maximum number of columns in a table definition or in the 2235** result set of a SELECT or the maximum number of columns in an index 2236** or in an ORDER BY or GROUP BY clause.</dd> 2237** 2238** <dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 2239** <dd>The maximum depth of the parse tree on any expression.</dd> 2240** 2241** <dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 2242** <dd>The maximum number of terms in a compound SELECT statement.</dd> 2243** 2244** <dt>SQLITE_LIMIT_VDBE_OP</dt> 2245** <dd>The maximum number of instructions in a virtual machine program 2246** used to implement an SQL statement.</dd> 2247** 2248** <dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 2249** <dd>The maximum number of arguments on a function.</dd> 2250** 2251** <dt>SQLITE_LIMIT_ATTACHED</dt> 2252** <dd>The maximum number of attached databases.</dd> 2253** 2254** <dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 2255** <dd>The maximum length of the pattern argument to the LIKE or 2256** GLOB operators.</dd> 2257** 2258** <dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 2259** <dd>The maximum number of variables in an SQL statement that can 2260** be bound.</dd> 2261** </dl> 2262*/ 2263#define SQLITE_LIMIT_LENGTH 0 2264#define SQLITE_LIMIT_SQL_LENGTH 1 2265#define SQLITE_LIMIT_COLUMN 2 2266#define SQLITE_LIMIT_EXPR_DEPTH 3 2267#define SQLITE_LIMIT_COMPOUND_SELECT 4 2268#define SQLITE_LIMIT_VDBE_OP 5 2269#define SQLITE_LIMIT_FUNCTION_ARG 6 2270#define SQLITE_LIMIT_ATTACHED 7 2271#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 2272#define SQLITE_LIMIT_VARIABLE_NUMBER 9 2273 2274/* 2275** CAPI3REF: Compiling An SQL Statement {F13010} 2276** 2277** To execute an SQL query, it must first be compiled into a byte-code 2278** program using one of these routines. 2279** 2280** The first argument "db" is an [database connection] 2281** obtained from a prior call to [sqlite3_open()], [sqlite3_open_v2()] 2282** or [sqlite3_open16()]. 2283** The second argument "zSql" is the statement to be compiled, encoded 2284** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() 2285** interfaces uses UTF-8 and sqlite3_prepare16() and sqlite3_prepare16_v2() 2286** use UTF-16. {END} 2287** 2288** If the nByte argument is less 2289** than zero, then zSql is read up to the first zero terminator. 2290** If nByte is non-negative, then it is the maximum number of 2291** bytes read from zSql. When nByte is non-negative, the 2292** zSql string ends at either the first '\000' or '\u0000' character or 2293** the nByte-th byte, whichever comes first. If the caller knows 2294** that the supplied string is nul-terminated, then there is a small 2295** performance advantage to be had by passing an nByte parameter that 2296** is equal to the number of bytes in the input string <i>including</i> 2297** the nul-terminator bytes.{END} 2298** 2299** *pzTail is made to point to the first byte past the end of the 2300** first SQL statement in zSql. These routines only compiles the first 2301** statement in zSql, so *pzTail is left pointing to what remains 2302** uncompiled. 2303** 2304** *ppStmt is left pointing to a compiled [prepared statement] that can be 2305** executed using [sqlite3_step()]. Or if there is an error, *ppStmt is 2306** set to NULL. If the input text contains no SQL (if the input 2307** is and empty string or a comment) then *ppStmt is set to NULL. 2308** {U13018} The calling procedure is responsible for deleting the 2309** compiled SQL statement 2310** using [sqlite3_finalize()] after it has finished with it. 2311** 2312** On success, [SQLITE_OK] is returned. Otherwise an 2313** [error code] is returned. 2314** 2315** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are 2316** recommended for all new programs. The two older interfaces are retained 2317** for backwards compatibility, but their use is discouraged. 2318** In the "v2" interfaces, the prepared statement 2319** that is returned (the [sqlite3_stmt] object) contains a copy of the 2320** original SQL text. {END} This causes the [sqlite3_step()] interface to 2321** behave a differently in two ways: 2322** 2323** <ol> 2324** <li> 2325** If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 2326** always used to do, [sqlite3_step()] will automatically recompile the SQL 2327** statement and try to run it again. If the schema has changed in 2328** a way that makes the statement no longer valid, [sqlite3_step()] will still 2329** return [SQLITE_SCHEMA]. But unlike the legacy behavior, 2330** [SQLITE_SCHEMA] is now a fatal error. Calling 2331** [sqlite3_prepare_v2()] again will not make the 2332** error go away. Note: use [sqlite3_errmsg()] to find the text 2333** of the parsing error that results in an [SQLITE_SCHEMA] return. {END} 2334** </li> 2335** 2336** <li> 2337** When an error occurs, 2338** [sqlite3_step()] will return one of the detailed 2339** [error codes] or [extended error codes]. 2340** The legacy behavior was that [sqlite3_step()] would only return a generic 2341** [SQLITE_ERROR] result code and you would have to make a second call to 2342** [sqlite3_reset()] in order to find the underlying cause of the problem. 2343** With the "v2" prepare interfaces, the underlying reason for the error is 2344** returned immediately. 2345** </li> 2346** </ol> 2347** 2348** INVARIANTS: 2349** 2350** {F13011} The [sqlite3_prepare(db,zSql,...)] and 2351** [sqlite3_prepare_v2(db,zSql,...)] interfaces interpret the 2352** text in their zSql parameter as UTF-8. 2353** 2354** {F13012} The [sqlite3_prepare16(db,zSql,...)] and 2355** [sqlite3_prepare16_v2(db,zSql,...)] interfaces interpret the 2356** text in their zSql parameter as UTF-16 in the native byte order. 2357** 2358** {F13013} If the nByte argument to [sqlite3_prepare_v2(db,zSql,nByte,...)] 2359** and its variants is less than zero, then SQL text is 2360** read from zSql is read up to the first zero terminator. 2361** 2362** {F13014} If the nByte argument to [sqlite3_prepare_v2(db,zSql,nByte,...)] 2363** and its variants is non-negative, then at most nBytes bytes 2364** SQL text is read from zSql. 2365** 2366** {F13015} In [sqlite3_prepare_v2(db,zSql,N,P,pzTail)] and its variants 2367** if the zSql input text contains more than one SQL statement 2368** and pzTail is not NULL, then *pzTail is made to point to the 2369** first byte past the end of the first SQL statement in zSql. 2370** <todo>What does *pzTail point to if there is one statement?</todo> 2371** 2372** {F13016} A successful call to [sqlite3_prepare_v2(db,zSql,N,ppStmt,...)] 2373** or one of its variants writes into *ppStmt a pointer to a new 2374** [prepared statement] or a pointer to NULL 2375** if zSql contains nothing other than whitespace or comments. 2376** 2377** {F13019} The [sqlite3_prepare_v2()] interface and its variants return 2378** [SQLITE_OK] or an appropriate [error code] upon failure. 2379** 2380** {F13021} Before [sqlite3_prepare(db,zSql,nByte,ppStmt,pzTail)] or its 2381** variants returns an error (any value other than [SQLITE_OK]) 2382** it first sets *ppStmt to NULL. 2383*/ 2384int sqlite3_prepare( 2385 sqlite3 *db, /* Database handle */ 2386 const char *zSql, /* SQL statement, UTF-8 encoded */ 2387 int nByte, /* Maximum length of zSql in bytes. */ 2388 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2389 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 2390); 2391int sqlite3_prepare_v2( 2392 sqlite3 *db, /* Database handle */ 2393 const char *zSql, /* SQL statement, UTF-8 encoded */ 2394 int nByte, /* Maximum length of zSql in bytes. */ 2395 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2396 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 2397); 2398int sqlite3_prepare16( 2399 sqlite3 *db, /* Database handle */ 2400 const void *zSql, /* SQL statement, UTF-16 encoded */ 2401 int nByte, /* Maximum length of zSql in bytes. */ 2402 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2403 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 2404); 2405int sqlite3_prepare16_v2( 2406 sqlite3 *db, /* Database handle */ 2407 const void *zSql, /* SQL statement, UTF-16 encoded */ 2408 int nByte, /* Maximum length of zSql in bytes. */ 2409 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 2410 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 2411); 2412 2413/* 2414** CAPIREF: Retrieving Statement SQL {F13100} 2415** 2416** This intereface can be used to retrieve a saved copy of the original 2417** SQL text used to create a [prepared statement]. 2418** 2419** INVARIANTS: 2420** 2421** {F13101} If the [prepared statement] passed as 2422** the an argument to [sqlite3_sql()] was compiled 2423** compiled using either [sqlite3_prepare_v2()] or 2424** [sqlite3_prepare16_v2()], 2425** then [sqlite3_sql()] function returns a pointer to a 2426** zero-terminated string containing a UTF-8 rendering 2427** of the original SQL statement. 2428** 2429** {F13102} If the [prepared statement] passed as 2430** the an argument to [sqlite3_sql()] was compiled 2431** compiled using either [sqlite3_prepare()] or 2432** [sqlite3_prepare16()], 2433** then [sqlite3_sql()] function returns a NULL pointer. 2434** 2435** {F13103} The string returned by [sqlite3_sql(S)] is valid until the 2436** [prepared statement] S is deleted using [sqlite3_finalize(S)]. 2437*/ 2438const char *sqlite3_sql(sqlite3_stmt *pStmt); 2439 2440/* 2441** CAPI3REF: Dynamically Typed Value Object {F15000} 2442** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 2443** 2444** SQLite uses the sqlite3_value object to represent all values 2445** that can be stored in a database table. 2446** SQLite uses dynamic typing for the values it stores. 2447** Values stored in sqlite3_value objects can be 2448** be integers, floating point values, strings, BLOBs, or NULL. 2449** 2450** An sqlite3_value object may be either "protected" or "unprotected". 2451** Some interfaces require a protected sqlite3_value. Other interfaces 2452** will accept either a protected or an unprotected sqlite3_value. 2453** Every interface that accepts sqlite3_value arguments specifies 2454** whether or not it requires a protected sqlite3_value. 2455** 2456** The terms "protected" and "unprotected" refer to whether or not 2457** a mutex is held. A internal mutex is held for a protected 2458** sqlite3_value object but no mutex is held for an unprotected 2459** sqlite3_value object. If SQLite is compiled to be single-threaded 2460** (with SQLITE_THREADSAFE=0 and with [sqlite3_threadsafe()] returning 0) 2461** then there is no distinction between 2462** protected and unprotected sqlite3_value objects and they can be 2463** used interchangable. However, for maximum code portability it 2464** is recommended that applications make the distinction between 2465** between protected and unprotected sqlite3_value objects even if 2466** they are single threaded. 2467** 2468** The sqlite3_value objects that are passed as parameters into the 2469** implementation of application-defined SQL functions are protected. 2470** The sqlite3_value object returned by 2471** [sqlite3_column_value()] is unprotected. 2472** Unprotected sqlite3_value objects may only be used with 2473** [sqlite3_result_value()] and [sqlite3_bind_value()]. All other 2474** interfaces that use sqlite3_value require protected sqlite3_value objects. 2475*/ 2476typedef struct Mem sqlite3_value; 2477 2478/* 2479** CAPI3REF: SQL Function Context Object {F16001} 2480** 2481** The context in which an SQL function executes is stored in an 2482** sqlite3_context object. A pointer to an sqlite3_context 2483** object is always first parameter to application-defined SQL functions. 2484*/ 2485typedef struct sqlite3_context sqlite3_context; 2486 2487/* 2488** CAPI3REF: Binding Values To Prepared Statements {F13500} 2489** 2490** In the SQL strings input to [sqlite3_prepare_v2()] and its 2491** variants, literals may be replace by a parameter in one 2492** of these forms: 2493** 2494** <ul> 2495** <li> ? 2496** <li> ?NNN 2497** <li> :VVV 2498** <li> @VVV 2499** <li> $VVV 2500** </ul> 2501** 2502** In the parameter forms shown above NNN is an integer literal, 2503** VVV alpha-numeric parameter name. 2504** The values of these parameters (also called "host parameter names" 2505** or "SQL parameters") 2506** can be set using the sqlite3_bind_*() routines defined here. 2507** 2508** The first argument to the sqlite3_bind_*() routines always 2509** is a pointer to the [sqlite3_stmt] object returned from 2510** [sqlite3_prepare_v2()] or its variants. The second 2511** argument is the index of the parameter to be set. The 2512** first parameter has an index of 1. When the same named 2513** parameter is used more than once, second and subsequent 2514** occurrences have the same index as the first occurrence. 2515** The index for named parameters can be looked up using the 2516** [sqlite3_bind_parameter_name()] API if desired. The index 2517** for "?NNN" parameters is the value of NNN. 2518** The NNN value must be between 1 and the compile-time 2519** parameter SQLITE_MAX_VARIABLE_NUMBER (default value: 999). 2520** 2521** The third argument is the value to bind to the parameter. 2522** 2523** In those 2524** routines that have a fourth argument, its value is the number of bytes 2525** in the parameter. To be clear: the value is the number of <u>bytes</u> 2526** in the value, not the number of characters. 2527** If the fourth parameter is negative, the length of the string is 2528** number of bytes up to the first zero terminator. 2529** 2530** The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and 2531** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or 2532** string after SQLite has finished with it. If the fifth argument is 2533** the special value [SQLITE_STATIC], then SQLite assumes that the 2534** information is in static, unmanaged space and does not need to be freed. 2535** If the fifth argument has the value [SQLITE_TRANSIENT], then 2536** SQLite makes its own private copy of the data immediately, before 2537** the sqlite3_bind_*() routine returns. 2538** 2539** The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 2540** is filled with zeros. A zeroblob uses a fixed amount of memory 2541** (just an integer to hold it size) while it is being processed. 2542** Zeroblobs are intended to serve as place-holders for BLOBs whose 2543** content is later written using 2544** [sqlite3_blob_open | increment BLOB I/O] routines. A negative 2545** value for the zeroblob results in a zero-length BLOB. 2546** 2547** The sqlite3_bind_*() routines must be called after 2548** [sqlite3_prepare_v2()] (and its variants) or [sqlite3_reset()] and 2549** before [sqlite3_step()]. 2550** Bindings are not cleared by the [sqlite3_reset()] routine. 2551** Unbound parameters are interpreted as NULL. 2552** 2553** These routines return [SQLITE_OK] on success or an error code if 2554** anything goes wrong. [SQLITE_RANGE] is returned if the parameter 2555** index is out of range. [SQLITE_NOMEM] is returned if malloc fails. 2556** [SQLITE_MISUSE] might be returned if these routines are called on a 2557** virtual machine that is the wrong state or which has already been finalized. 2558** Detection of misuse is unreliable. Applications should not depend 2559** on SQLITE_MISUSE returns. SQLITE_MISUSE is intended to indicate a 2560** a logic error in the application. Future versions of SQLite might 2561** panic rather than return SQLITE_MISUSE. 2562** 2563** See also: [sqlite3_bind_parameter_count()], 2564** [sqlite3_bind_parameter_name()], and 2565** [sqlite3_bind_parameter_index()]. 2566** 2567** INVARIANTS: 2568** 2569** {F13506} The [sqlite3_prepare | SQL statement compiler] recognizes 2570** tokens of the forms "?", "?NNN", "$VVV", ":VVV", and "@VVV" 2571** as SQL parameters, where NNN is any sequence of one or more 2572** digits and where VVV is any sequence of one or more 2573** alphanumeric characters or "::" optionally followed by 2574** a string containing no spaces and contained within parentheses. 2575** 2576** {F13509} The initial value of an SQL parameter is NULL. 2577** 2578** {F13512} The index of an "?" SQL parameter is one larger than the 2579** largest index of SQL parameter to the left, or 1 if 2580** the "?" is the leftmost SQL parameter. 2581** 2582** {F13515} The index of an "?NNN" SQL parameter is the integer NNN. 2583** 2584** {F13518} The index of an ":VVV", "$VVV", or "@VVV" SQL parameter is 2585** the same as the index of leftmost occurances of the same 2586** parameter, or one more than the largest index over all 2587** parameters to the left if this is the first occurrance 2588** of this parameter, or 1 if this is the leftmost parameter. 2589** 2590** {F13521} The [sqlite3_prepare | SQL statement compiler] fail with 2591** an [SQLITE_RANGE] error if the index of an SQL parameter 2592** is less than 1 or greater than SQLITE_MAX_VARIABLE_NUMBER. 2593** 2594** {F13524} Calls to [sqlite3_bind_text | sqlite3_bind(S,N,V,...)] 2595** associate the value V with all SQL parameters having an 2596** index of N in the [prepared statement] S. 2597** 2598** {F13527} Calls to [sqlite3_bind_text | sqlite3_bind(S,N,...)] 2599** override prior calls with the same values of S and N. 2600** 2601** {F13530} Bindings established by [sqlite3_bind_text | sqlite3_bind(S,...)] 2602** persist across calls to [sqlite3_reset(S)]. 2603** 2604** {F13533} In calls to [sqlite3_bind_blob(S,N,V,L,D)], 2605** [sqlite3_bind_text(S,N,V,L,D)], or 2606** [sqlite3_bind_text16(S,N,V,L,D)] SQLite binds the first L 2607** bytes of the blob or string pointed to by V, when L 2608** is non-negative. 2609** 2610** {F13536} In calls to [sqlite3_bind_text(S,N,V,L,D)] or 2611** [sqlite3_bind_text16(S,N,V,L,D)] SQLite binds characters 2612** from V through the first zero character when L is negative. 2613** 2614** {F13539} In calls to [sqlite3_bind_blob(S,N,V,L,D)], 2615** [sqlite3_bind_text(S,N,V,L,D)], or 2616** [sqlite3_bind_text16(S,N,V,L,D)] when D is the special 2617** constant [SQLITE_STATIC], SQLite assumes that the value V 2618** is held in static unmanaged space that will not change 2619** during the lifetime of the binding. 2620** 2621** {F13542} In calls to [sqlite3_bind_blob(S,N,V,L,D)], 2622** [sqlite3_bind_text(S,N,V,L,D)], or 2623** [sqlite3_bind_text16(S,N,V,L,D)] when D is the special 2624** constant [SQLITE_TRANSIENT], the routine makes a 2625** private copy of V value before it returns. 2626** 2627** {F13545} In calls to [sqlite3_bind_blob(S,N,V,L,D)], 2628** [sqlite3_bind_text(S,N,V,L,D)], or 2629** [sqlite3_bind_text16(S,N,V,L,D)] when D is a pointer to 2630** a function, SQLite invokes that function to destroy the 2631** V value after it has finished using the V value. 2632** 2633** {F13548} In calls to [sqlite3_bind_zeroblob(S,N,V,L)] the value bound 2634** is a blob of L bytes, or a zero-length blob if L is negative. 2635** 2636** {F13551} In calls to [sqlite3_bind_value(S,N,V)] the V argument may 2637** be either a [protected sqlite3_value] object or an 2638** [unprotected sqlite3_value] object. 2639*/ 2640int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 2641int sqlite3_bind_double(sqlite3_stmt*, int, double); 2642int sqlite3_bind_int(sqlite3_stmt*, int, int); 2643int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 2644int sqlite3_bind_null(sqlite3_stmt*, int); 2645int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*)); 2646int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 2647int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 2648int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 2649 2650/* 2651** CAPI3REF: Number Of SQL Parameters {F13600} 2652** 2653** This routine can be used to find the number of SQL parameters 2654** in a prepared statement. SQL parameters are tokens of the 2655** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 2656** place-holders for values that are [sqlite3_bind_blob | bound] 2657** to the parameters at a later time. 2658** 2659** This routine actually returns the index of the largest parameter. 2660** For all forms except ?NNN, this will correspond to the number of 2661** unique parameters. If parameters of the ?NNN are used, there may 2662** be gaps in the list. 2663** 2664** See also: [sqlite3_bind_blob|sqlite3_bind()], 2665** [sqlite3_bind_parameter_name()], and 2666** [sqlite3_bind_parameter_index()]. 2667** 2668** INVARIANTS: 2669** 2670** {F13601} The [sqlite3_bind_parameter_count(S)] interface returns 2671** the largest index of all SQL parameters in the 2672** [prepared statement] S, or 0 if S 2673** contains no SQL parameters. 2674*/ 2675int sqlite3_bind_parameter_count(sqlite3_stmt*); 2676 2677/* 2678** CAPI3REF: Name Of A Host Parameter {F13620} 2679** 2680** This routine returns a pointer to the name of the n-th 2681** SQL parameter in a [prepared statement]. 2682** SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 2683** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 2684** respectively. 2685** In other words, the initial ":" or "$" or "@" or "?" 2686** is included as part of the name. 2687** Parameters of the form "?" without a following integer have no name. 2688** 2689** The first host parameter has an index of 1, not 0. 2690** 2691** If the value n is out of range or if the n-th parameter is 2692** nameless, then NULL is returned. The returned string is 2693** always in the UTF-8 encoding even if the named parameter was 2694** originally specified as UTF-16 in [sqlite3_prepare16()] or 2695** [sqlite3_prepare16_v2()]. 2696** 2697** See also: [sqlite3_bind_blob|sqlite3_bind()], 2698** [sqlite3_bind_parameter_count()], and 2699** [sqlite3_bind_parameter_index()]. 2700** 2701** INVARIANTS: 2702** 2703** {F13621} The [sqlite3_bind_parameter_name(S,N)] interface returns 2704** a UTF-8 rendering of the name of the SQL parameter in 2705** [prepared statement] S having index N, or 2706** NULL if there is no SQL parameter with index N or if the 2707** parameter with index N is an anonymous parameter "?". 2708*/ 2709const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 2710 2711/* 2712** CAPI3REF: Index Of A Parameter With A Given Name {F13640} 2713** 2714** Return the index of an SQL parameter given its name. The 2715** index value returned is suitable for use as the second 2716** parameter to [sqlite3_bind_blob|sqlite3_bind()]. A zero 2717** is returned if no matching parameter is found. The parameter 2718** name must be given in UTF-8 even if the original statement 2719** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. 2720** 2721** See also: [sqlite3_bind_blob|sqlite3_bind()], 2722** [sqlite3_bind_parameter_count()], and 2723** [sqlite3_bind_parameter_index()]. 2724** 2725** INVARIANTS: 2726** 2727** {F13641} The [sqlite3_bind_parameter_index(S,N)] interface returns 2728** the index of SQL parameter in [prepared statement] 2729** S whose name matches the UTF-8 string N, or 0 if there is 2730** no match. 2731*/ 2732int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 2733 2734/* 2735** CAPI3REF: Reset All Bindings On A Prepared Statement {F13660} 2736** 2737** Contrary to the intuition of many, [sqlite3_reset()] does not 2738** reset the [sqlite3_bind_blob | bindings] on a 2739** [prepared statement]. Use this routine to 2740** reset all host parameters to NULL. 2741** 2742** INVARIANTS: 2743** 2744** {F13661} The [sqlite3_clear_bindings(S)] interface resets all 2745** SQL parameter bindings in [prepared statement] S 2746** back to NULL. 2747*/ 2748int sqlite3_clear_bindings(sqlite3_stmt*); 2749 2750/* 2751** CAPI3REF: Number Of Columns In A Result Set {F13710} 2752** 2753** Return the number of columns in the result set returned by the 2754** [prepared statement]. This routine returns 0 2755** if pStmt is an SQL statement that does not return data (for 2756** example an UPDATE). 2757** 2758** INVARIANTS: 2759** 2760** {F13711} The [sqlite3_column_count(S)] interface returns the number of 2761** columns in the result set generated by the 2762** [prepared statement] S, or 0 if S does not generate 2763** a result set. 2764*/ 2765int sqlite3_column_count(sqlite3_stmt *pStmt); 2766 2767/* 2768** CAPI3REF: Column Names In A Result Set {F13720} 2769** 2770** These routines return the name assigned to a particular column 2771** in the result set of a SELECT statement. The sqlite3_column_name() 2772** interface returns a pointer to a zero-terminated UTF8 string 2773** and sqlite3_column_name16() returns a pointer to a zero-terminated 2774** UTF16 string. The first parameter is the 2775** [prepared statement] that implements the SELECT statement. 2776** The second parameter is the column number. The left-most column is 2777** number 0. 2778** 2779** The returned string pointer is valid until either the 2780** [prepared statement] is destroyed by [sqlite3_finalize()] 2781** or until the next call sqlite3_column_name() or sqlite3_column_name16() 2782** on the same column. 2783** 2784** If sqlite3_malloc() fails during the processing of either routine 2785** (for example during a conversion from UTF-8 to UTF-16) then a 2786** NULL pointer is returned. 2787** 2788** The name of a result column is the value of the "AS" clause for 2789** that column, if there is an AS clause. If there is no AS clause 2790** then the name of the column is unspecified and may change from 2791** one release of SQLite to the next. 2792** 2793** INVARIANTS: 2794** 2795** {F13721} A successful invocation of the [sqlite3_column_name(S,N)] 2796** interface returns the name 2797** of the Nth column (where 0 is the left-most column) for the 2798** result set of [prepared statement] S as a 2799** zero-terminated UTF-8 string. 2800** 2801** {F13723} A successful invocation of the [sqlite3_column_name16(S,N)] 2802** interface returns the name 2803** of the Nth column (where 0 is the left-most column) for the 2804** result set of [prepared statement] S as a 2805** zero-terminated UTF-16 string in the native byte order. 2806** 2807** {F13724} The [sqlite3_column_name()] and [sqlite3_column_name16()] 2808** interfaces return a NULL pointer if they are unable to 2809** allocate memory memory to hold there normal return strings. 2810** 2811** {F13725} If the N parameter to [sqlite3_column_name(S,N)] or 2812** [sqlite3_column_name16(S,N)] is out of range, then the 2813** interfaces returns a NULL pointer. 2814** 2815** {F13726} The strings returned by [sqlite3_column_name(S,N)] and 2816** [sqlite3_column_name16(S,N)] are valid until the next 2817** call to either routine with the same S and N parameters 2818** or until [sqlite3_finalize(S)] is called. 2819** 2820** {F13727} When a result column of a [SELECT] statement contains 2821** an AS clause, the name of that column is the indentifier 2822** to the right of the AS keyword. 2823*/ 2824const char *sqlite3_column_name(sqlite3_stmt*, int N); 2825const void *sqlite3_column_name16(sqlite3_stmt*, int N); 2826 2827/* 2828** CAPI3REF: Source Of Data In A Query Result {F13740} 2829** 2830** These routines provide a means to determine what column of what 2831** table in which database a result of a SELECT statement comes from. 2832** The name of the database or table or column can be returned as 2833** either a UTF8 or UTF16 string. The _database_ routines return 2834** the database name, the _table_ routines return the table name, and 2835** the origin_ routines return the column name. 2836** The returned string is valid until 2837** the [prepared statement] is destroyed using 2838** [sqlite3_finalize()] or until the same information is requested 2839** again in a different encoding. 2840** 2841** The names returned are the original un-aliased names of the 2842** database, table, and column. 2843** 2844** The first argument to the following calls is a [prepared statement]. 2845** These functions return information about the Nth column returned by 2846** the statement, where N is the second function argument. 2847** 2848** If the Nth column returned by the statement is an expression 2849** or subquery and is not a column value, then all of these functions 2850** return NULL. These routine might also return NULL if a memory 2851** allocation error occurs. Otherwise, they return the 2852** name of the attached database, table and column that query result 2853** column was extracted from. 2854** 2855** As with all other SQLite APIs, those postfixed with "16" return 2856** UTF-16 encoded strings, the other functions return UTF-8. {END} 2857** 2858** These APIs are only available if the library was compiled with the 2859** SQLITE_ENABLE_COLUMN_METADATA preprocessor symbol defined. 2860** 2861** {U13751} 2862** If two or more threads call one or more of these routines against the same 2863** prepared statement and column at the same time then the results are 2864** undefined. 2865** 2866** INVARIANTS: 2867** 2868** {F13741} The [sqlite3_column_database_name(S,N)] interface returns either 2869** the UTF-8 zero-terminated name of the database from which the 2870** Nth result column of [prepared statement] S 2871** is extracted, or NULL if the the Nth column of S is a 2872** general expression or if unable to allocate memory 2873** to store the name. 2874** 2875** {F13742} The [sqlite3_column_database_name16(S,N)] interface returns either 2876** the UTF-16 native byte order 2877** zero-terminated name of the database from which the 2878** Nth result column of [prepared statement] S 2879** is extracted, or NULL if the the Nth column of S is a 2880** general expression or if unable to allocate memory 2881** to store the name. 2882** 2883** {F13743} The [sqlite3_column_table_name(S,N)] interface returns either 2884** the UTF-8 zero-terminated name of the table from which the 2885** Nth result column of [prepared statement] S 2886** is extracted, or NULL if the the Nth column of S is a 2887** general expression or if unable to allocate memory 2888** to store the name. 2889** 2890** {F13744} The [sqlite3_column_table_name16(S,N)] interface returns either 2891** the UTF-16 native byte order 2892** zero-terminated name of the table from which the 2893** Nth result column of [prepared statement] S 2894** is extracted, or NULL if the the Nth column of S is a 2895** general expression or if unable to allocate memory 2896** to store the name. 2897** 2898** {F13745} The [sqlite3_column_origin_name(S,N)] interface returns either 2899** the UTF-8 zero-terminated name of the table column from which the 2900** Nth result column of [prepared statement] S 2901** is extracted, or NULL if the the Nth column of S is a 2902** general expression or if unable to allocate memory 2903** to store the name. 2904** 2905** {F13746} The [sqlite3_column_origin_name16(S,N)] interface returns either 2906** the UTF-16 native byte order 2907** zero-terminated name of the table column from which the 2908** Nth result column of [prepared statement] S 2909** is extracted, or NULL if the the Nth column of S is a 2910** general expression or if unable to allocate memory 2911** to store the name. 2912** 2913** {F13748} The return values from 2914** [sqlite3_column_database_name|column metadata interfaces] 2915** are valid 2916** for the lifetime of the [prepared statement] 2917** or until the encoding is changed by another metadata 2918** interface call for the same prepared statement and column. 2919** 2920** LIMITATIONS: 2921** 2922** {U13751} If two or more threads call one or more 2923** [sqlite3_column_database_name|column metadata interfaces] 2924** the same [prepared statement] and result column 2925** at the same time then the results are undefined. 2926*/ 2927const char *sqlite3_column_database_name(sqlite3_stmt*,int); 2928const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 2929const char *sqlite3_column_table_name(sqlite3_stmt*,int); 2930const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 2931const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 2932const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 2933 2934/* 2935** CAPI3REF: Declared Datatype Of A Query Result {F13760} 2936** 2937** The first parameter is a [prepared statement]. 2938** If this statement is a SELECT statement and the Nth column of the 2939** returned result set of that SELECT is a table column (not an 2940** expression or subquery) then the declared type of the table 2941** column is returned. If the Nth column of the result set is an 2942** expression or subquery, then a NULL pointer is returned. 2943** The returned string is always UTF-8 encoded. {END} 2944** For example, in the database schema: 2945** 2946** CREATE TABLE t1(c1 VARIANT); 2947** 2948** And the following statement compiled: 2949** 2950** SELECT c1 + 1, c1 FROM t1; 2951** 2952** Then this routine would return the string "VARIANT" for the second 2953** result column (i==1), and a NULL pointer for the first result column 2954** (i==0). 2955** 2956** SQLite uses dynamic run-time typing. So just because a column 2957** is declared to contain a particular type does not mean that the 2958** data stored in that column is of the declared type. SQLite is 2959** strongly typed, but the typing is dynamic not static. Type 2960** is associated with individual values, not with the containers 2961** used to hold those values. 2962** 2963** INVARIANTS: 2964** 2965** {F13761} A successful call to [sqlite3_column_decltype(S,N)] 2966** returns a zero-terminated UTF-8 string containing the 2967** the declared datatype of the table column that appears 2968** as the Nth column (numbered from 0) of the result set to the 2969** [prepared statement] S. 2970** 2971** {F13762} A successful call to [sqlite3_column_decltype16(S,N)] 2972** returns a zero-terminated UTF-16 native byte order string 2973** containing the declared datatype of the table column that appears 2974** as the Nth column (numbered from 0) of the result set to the 2975** [prepared statement] S. 2976** 2977** {F13763} If N is less than 0 or N is greater than or equal to 2978** the number of columns in [prepared statement] S 2979** or if the Nth column of S is an expression or subquery rather 2980** than a table column or if a memory allocation failure 2981** occurs during encoding conversions, then 2982** calls to [sqlite3_column_decltype(S,N)] or 2983** [sqlite3_column_decltype16(S,N)] return NULL. 2984*/ 2985const char *sqlite3_column_decltype(sqlite3_stmt*,int); 2986const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 2987 2988/* 2989** CAPI3REF: Evaluate An SQL Statement {F13200} 2990** 2991** After an [prepared statement] has been prepared with a call 2992** to either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or to one of 2993** the legacy interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], 2994** then this function must be called one or more times to evaluate the 2995** statement. 2996** 2997** The details of the behavior of this sqlite3_step() interface depend 2998** on whether the statement was prepared using the newer "v2" interface 2999** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy 3000** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 3001** new "v2" interface is recommended for new applications but the legacy 3002** interface will continue to be supported. 3003** 3004** In the legacy interface, the return value will be either [SQLITE_BUSY], 3005** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 3006** With the "v2" interface, any of the other [SQLITE_OK | result code] 3007** or [SQLITE_IOERR_READ | extended result code] might be returned as 3008** well. 3009** 3010** [SQLITE_BUSY] means that the database engine was unable to acquire the 3011** database locks it needs to do its job. If the statement is a COMMIT 3012** or occurs outside of an explicit transaction, then you can retry the 3013** statement. If the statement is not a COMMIT and occurs within a 3014** explicit transaction then you should rollback the transaction before 3015** continuing. 3016** 3017** [SQLITE_DONE] means that the statement has finished executing 3018** successfully. sqlite3_step() should not be called again on this virtual 3019** machine without first calling [sqlite3_reset()] to reset the virtual 3020** machine back to its initial state. 3021** 3022** If the SQL statement being executed returns any data, then 3023** [SQLITE_ROW] is returned each time a new row of data is ready 3024** for processing by the caller. The values may be accessed using 3025** the [sqlite3_column_int | column access functions]. 3026** sqlite3_step() is called again to retrieve the next row of data. 3027** 3028** [SQLITE_ERROR] means that a run-time error (such as a constraint 3029** violation) has occurred. sqlite3_step() should not be called again on 3030** the VM. More information may be found by calling [sqlite3_errmsg()]. 3031** With the legacy interface, a more specific error code (example: 3032** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 3033** can be obtained by calling [sqlite3_reset()] on the 3034** [prepared statement]. In the "v2" interface, 3035** the more specific error code is returned directly by sqlite3_step(). 3036** 3037** [SQLITE_MISUSE] means that the this routine was called inappropriately. 3038** Perhaps it was called on a [prepared statement] that has 3039** already been [sqlite3_finalize | finalized] or on one that had 3040** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 3041** be the case that the same database connection is being used by two or 3042** more threads at the same moment in time. 3043** 3044** <b>Goofy Interface Alert:</b> 3045** In the legacy interface, 3046** the sqlite3_step() API always returns a generic error code, 3047** [SQLITE_ERROR], following any error other than [SQLITE_BUSY] 3048** and [SQLITE_MISUSE]. You must call [sqlite3_reset()] or 3049** [sqlite3_finalize()] in order to find one of the specific 3050** [error codes] that better describes the error. 3051** We admit that this is a goofy design. The problem has been fixed 3052** with the "v2" interface. If you prepare all of your SQL statements 3053** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead 3054** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()], then the 3055** more specific [error codes] are returned directly 3056** by sqlite3_step(). The use of the "v2" interface is recommended. 3057** 3058** INVARIANTS: 3059** 3060** {F13202} If [prepared statement] S is ready to be 3061** run, then [sqlite3_step(S)] advances that prepared statement 3062** until to completion or until it is ready to return another 3063** row of the result set or an interrupt or run-time error occurs. 3064** 3065** {F15304} When a call to [sqlite3_step(S)] causes the 3066** [prepared statement] S to run to completion, 3067** the function returns [SQLITE_DONE]. 3068** 3069** {F15306} When a call to [sqlite3_step(S)] stops because it is ready 3070** to return another row of the result set, it returns 3071** [SQLITE_ROW]. 3072** 3073** {F15308} If a call to [sqlite3_step(S)] encounters an 3074** [sqlite3_interrupt|interrupt] or a run-time error, 3075** it returns an appropraite error code that is not one of 3076** [SQLITE_OK], [SQLITE_ROW], or [SQLITE_DONE]. 3077** 3078** {F15310} If an [sqlite3_interrupt|interrupt] or run-time error 3079** occurs during a call to [sqlite3_step(S)] 3080** for a [prepared statement] S created using 3081** legacy interfaces [sqlite3_prepare()] or 3082** [sqlite3_prepare16()] then the function returns either 3083** [SQLITE_ERROR], [SQLITE_BUSY], or [SQLITE_MISUSE]. 3084*/ 3085int sqlite3_step(sqlite3_stmt*); 3086 3087/* 3088** CAPI3REF: Number of columns in a result set {F13770} 3089** 3090** Return the number of values in the current row of the result set. 3091** 3092** INVARIANTS: 3093** 3094** {F13771} After a call to [sqlite3_step(S)] that returns 3095** [SQLITE_ROW], the [sqlite3_data_count(S)] routine 3096** will return the same value as the 3097** [sqlite3_column_count(S)] function. 3098** 3099** {F13772} After [sqlite3_step(S)] has returned any value other than 3100** [SQLITE_ROW] or before [sqlite3_step(S)] has been 3101** called on the [prepared statement] for 3102** the first time since it was [sqlite3_prepare|prepared] 3103** or [sqlite3_reset|reset], the [sqlite3_data_count(S)] 3104** routine returns zero. 3105*/ 3106int sqlite3_data_count(sqlite3_stmt *pStmt); 3107 3108/* 3109** CAPI3REF: Fundamental Datatypes {F10265} 3110** KEYWORDS: SQLITE_TEXT 3111** 3112** {F10266}Every value in SQLite has one of five fundamental datatypes: 3113** 3114** <ul> 3115** <li> 64-bit signed integer 3116** <li> 64-bit IEEE floating point number 3117** <li> string 3118** <li> BLOB 3119** <li> NULL 3120** </ul> {END} 3121** 3122** These constants are codes for each of those types. 3123** 3124** Note that the SQLITE_TEXT constant was also used in SQLite version 2 3125** for a completely different meaning. Software that links against both 3126** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT not 3127** SQLITE_TEXT. 3128*/ 3129#define SQLITE_INTEGER 1 3130#define SQLITE_FLOAT 2 3131#define SQLITE_BLOB 4 3132#define SQLITE_NULL 5 3133#ifdef SQLITE_TEXT 3134# undef SQLITE_TEXT 3135#else 3136# define SQLITE_TEXT 3 3137#endif 3138#define SQLITE3_TEXT 3 3139 3140/* 3141** CAPI3REF: Results Values From A Query {F13800} 3142** 3143** These routines form the "result set query" interface. 3144** 3145** These routines return information about 3146** a single column of the current result row of a query. In every 3147** case the first argument is a pointer to the 3148** [prepared statement] that is being 3149** evaluated (the [sqlite3_stmt*] that was returned from 3150** [sqlite3_prepare_v2()] or one of its variants) and 3151** the second argument is the index of the column for which information 3152** should be returned. The left-most column of the result set 3153** has an index of 0. 3154** 3155** If the SQL statement is not currently point to a valid row, or if the 3156** the column index is out of range, the result is undefined. 3157** These routines may only be called when the most recent call to 3158** [sqlite3_step()] has returned [SQLITE_ROW] and neither 3159** [sqlite3_reset()] nor [sqlite3_finalize()] has been call subsequently. 3160** If any of these routines are called after [sqlite3_reset()] or 3161** [sqlite3_finalize()] or after [sqlite3_step()] has returned 3162** something other than [SQLITE_ROW], the results are undefined. 3163** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 3164** are called from a different thread while any of these routines 3165** are pending, then the results are undefined. 3166** 3167** The sqlite3_column_type() routine returns 3168** [SQLITE_INTEGER | datatype code] for the initial data type 3169** of the result column. The returned value is one of [SQLITE_INTEGER], 3170** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value 3171** returned by sqlite3_column_type() is only meaningful if no type 3172** conversions have occurred as described below. After a type conversion, 3173** the value returned by sqlite3_column_type() is undefined. Future 3174** versions of SQLite may change the behavior of sqlite3_column_type() 3175** following a type conversion. 3176** 3177** If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 3178** routine returns the number of bytes in that BLOB or string. 3179** If the result is a UTF-16 string, then sqlite3_column_bytes() converts 3180** the string to UTF-8 and then returns the number of bytes. 3181** If the result is a numeric value then sqlite3_column_bytes() uses 3182** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 3183** the number of bytes in that string. 3184** The value returned does not include the zero terminator at the end 3185** of the string. For clarity: the value returned is the number of 3186** bytes in the string, not the number of characters. 3187** 3188** Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 3189** even empty strings, are always zero terminated. The return 3190** value from sqlite3_column_blob() for a zero-length blob is an arbitrary 3191** pointer, possibly even a NULL pointer. 3192** 3193** The sqlite3_column_bytes16() routine is similar to sqlite3_column_bytes() 3194** but leaves the result in UTF-16 in native byte order instead of UTF-8. 3195** The zero terminator is not included in this count. 3196** 3197** The object returned by [sqlite3_column_value()] is an 3198** [unprotected sqlite3_value] object. An unprotected sqlite3_value object 3199** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()]. 3200** If the [unprotected sqlite3_value] object returned by 3201** [sqlite3_column_value()] is used in any other way, including calls 3202** to routines like 3203** [sqlite3_value_int()], [sqlite3_value_text()], or [sqlite3_value_bytes()], 3204** then the behavior is undefined. 3205** 3206** These routines attempt to convert the value where appropriate. For 3207** example, if the internal representation is FLOAT and a text result 3208** is requested, [sqlite3_snprintf()] is used internally to do the conversion 3209** automatically. The following table details the conversions that 3210** are applied: 3211** 3212** <blockquote> 3213** <table border="1"> 3214** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 3215** 3216** <tr><td> NULL <td> INTEGER <td> Result is 0 3217** <tr><td> NULL <td> FLOAT <td> Result is 0.0 3218** <tr><td> NULL <td> TEXT <td> Result is NULL pointer 3219** <tr><td> NULL <td> BLOB <td> Result is NULL pointer 3220** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 3221** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 3222** <tr><td> INTEGER <td> BLOB <td> Same as for INTEGER->TEXT 3223** <tr><td> FLOAT <td> INTEGER <td> Convert from float to integer 3224** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 3225** <tr><td> FLOAT <td> BLOB <td> Same as FLOAT->TEXT 3226** <tr><td> TEXT <td> INTEGER <td> Use atoi() 3227** <tr><td> TEXT <td> FLOAT <td> Use atof() 3228** <tr><td> TEXT <td> BLOB <td> No change 3229** <tr><td> BLOB <td> INTEGER <td> Convert to TEXT then use atoi() 3230** <tr><td> BLOB <td> FLOAT <td> Convert to TEXT then use atof() 3231** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 3232** </table> 3233** </blockquote> 3234** 3235** The table above makes reference to standard C library functions atoi() 3236** and atof(). SQLite does not really use these functions. It has its 3237** on equavalent internal routines. The atoi() and atof() names are 3238** used in the table for brevity and because they are familiar to most 3239** C programmers. 3240** 3241** Note that when type conversions occur, pointers returned by prior 3242** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 3243** sqlite3_column_text16() may be invalidated. 3244** Type conversions and pointer invalidations might occur 3245** in the following cases: 3246** 3247** <ul> 3248** <li><p> The initial content is a BLOB and sqlite3_column_text() 3249** or sqlite3_column_text16() is called. A zero-terminator might 3250** need to be added to the string.</p></li> 3251** 3252** <li><p> The initial content is UTF-8 text and sqlite3_column_bytes16() or 3253** sqlite3_column_text16() is called. The content must be converted 3254** to UTF-16.</p></li> 3255** 3256** <li><p> The initial content is UTF-16 text and sqlite3_column_bytes() or 3257** sqlite3_column_text() is called. The content must be converted 3258** to UTF-8.</p></li> 3259** </ul> 3260** 3261** Conversions between UTF-16be and UTF-16le are always done in place and do 3262** not invalidate a prior pointer, though of course the content of the buffer 3263** that the prior pointer points to will have been modified. Other kinds 3264** of conversion are done in place when it is possible, but sometime it is 3265** not possible and in those cases prior pointers are invalidated. 3266** 3267** The safest and easiest to remember policy is to invoke these routines 3268** in one of the following ways: 3269** 3270** <ul> 3271** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 3272** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 3273** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 3274** </ul> 3275** 3276** In other words, you should call sqlite3_column_text(), sqlite3_column_blob(), 3277** or sqlite3_column_text16() first to force the result into the desired 3278** format, then invoke sqlite3_column_bytes() or sqlite3_column_bytes16() to 3279** find the size of the result. Do not mix call to sqlite3_column_text() or 3280** sqlite3_column_blob() with calls to sqlite3_column_bytes16(). And do not 3281** mix calls to sqlite3_column_text16() with calls to sqlite3_column_bytes(). 3282** 3283** The pointers returned are valid until a type conversion occurs as 3284** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 3285** [sqlite3_finalize()] is called. The memory space used to hold strings 3286** and blobs is freed automatically. Do <b>not</b> pass the pointers returned 3287** [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 3288** [sqlite3_free()]. 3289** 3290** If a memory allocation error occurs during the evaluation of any 3291** of these routines, a default value is returned. The default value 3292** is either the integer 0, the floating point number 0.0, or a NULL 3293** pointer. Subsequent calls to [sqlite3_errcode()] will return 3294** [SQLITE_NOMEM]. 3295** 3296** INVARIANTS: 3297** 3298** {F13803} The [sqlite3_column_blob(S,N)] interface converts the 3299** Nth column in the current row of the result set for 3300** [prepared statement] S into a blob and then returns a 3301** pointer to the converted value. 3302** 3303** {F13806} The [sqlite3_column_bytes(S,N)] interface returns the 3304** number of bytes in the blob or string (exclusive of the 3305** zero terminator on the string) that was returned by the 3306** most recent call to [sqlite3_column_blob(S,N)] or 3307** [sqlite3_column_text(S,N)]. 3308** 3309** {F13809} The [sqlite3_column_bytes16(S,N)] interface returns the 3310** number of bytes in the string (exclusive of the 3311** zero terminator on the string) that was returned by the 3312** most recent call to [sqlite3_column_text16(S,N)]. 3313** 3314** {F13812} The [sqlite3_column_double(S,N)] interface converts the 3315** Nth column in the current row of the result set for 3316** [prepared statement] S into a floating point value and 3317** returns a copy of that value. 3318** 3319** {F13815} The [sqlite3_column_int(S,N)] interface converts the 3320** Nth column in the current row of the result set for 3321** [prepared statement] S into a 64-bit signed integer and 3322** returns the lower 32 bits of that integer. 3323** 3324** {F13818} The [sqlite3_column_int64(S,N)] interface converts the 3325** Nth column in the current row of the result set for 3326** [prepared statement] S into a 64-bit signed integer and 3327** returns a copy of that integer. 3328** 3329** {F13821} The [sqlite3_column_text(S,N)] interface converts the 3330** Nth column in the current row of the result set for 3331** [prepared statement] S into a zero-terminated UTF-8 3332** string and returns a pointer to that string. 3333** 3334** {F13824} The [sqlite3_column_text16(S,N)] interface converts the 3335** Nth column in the current row of the result set for 3336** [prepared statement] S into a zero-terminated 2-byte 3337** aligned UTF-16 native byte order 3338** string and returns a pointer to that string. 3339** 3340** {F13827} The [sqlite3_column_type(S,N)] interface returns 3341** one of [SQLITE_NULL], [SQLITE_INTEGER], [SQLITE_FLOAT], 3342** [SQLITE_TEXT], or [SQLITE_BLOB] as appropriate for 3343** the Nth column in the current row of the result set for 3344** [prepared statement] S. 3345** 3346** {F13830} The [sqlite3_column_value(S,N)] interface returns a 3347** pointer to an [unprotected sqlite3_value] object for the 3348** Nth column in the current row of the result set for 3349** [prepared statement] S. 3350*/ 3351const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 3352int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 3353int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 3354double sqlite3_column_double(sqlite3_stmt*, int iCol); 3355int sqlite3_column_int(sqlite3_stmt*, int iCol); 3356sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 3357const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 3358const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 3359int sqlite3_column_type(sqlite3_stmt*, int iCol); 3360sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 3361 3362/* 3363** CAPI3REF: Destroy A Prepared Statement Object {F13300} 3364** 3365** The sqlite3_finalize() function is called to delete a 3366** [prepared statement]. If the statement was 3367** executed successfully, or not executed at all, then SQLITE_OK is returned. 3368** If execution of the statement failed then an 3369** [error code] or [extended error code] 3370** is returned. 3371** 3372** This routine can be called at any point during the execution of the 3373** [prepared statement]. If the virtual machine has not 3374** completed execution when this routine is called, that is like 3375** encountering an error or an interrupt. (See [sqlite3_interrupt()].) 3376** Incomplete updates may be rolled back and transactions cancelled, 3377** depending on the circumstances, and the 3378** [error code] returned will be [SQLITE_ABORT]. 3379** 3380** INVARIANTS: 3381** 3382** {F11302} The [sqlite3_finalize(S)] interface destroys the 3383** [prepared statement] S and releases all 3384** memory and file resources held by that object. 3385** 3386** {F11304} If the most recent call to [sqlite3_step(S)] for the 3387** [prepared statement] S returned an error, 3388** then [sqlite3_finalize(S)] returns that same error. 3389*/ 3390int sqlite3_finalize(sqlite3_stmt *pStmt); 3391 3392/* 3393** CAPI3REF: Reset A Prepared Statement Object {F13330} 3394** 3395** The sqlite3_reset() function is called to reset a 3396** [prepared statement] object. 3397** back to its initial state, ready to be re-executed. 3398** Any SQL statement variables that had values bound to them using 3399** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 3400** Use [sqlite3_clear_bindings()] to reset the bindings. 3401** 3402** {F11332} The [sqlite3_reset(S)] interface resets the [prepared statement] S 3403** back to the beginning of its program. 3404** 3405** {F11334} If the most recent call to [sqlite3_step(S)] for 3406** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 3407** or if [sqlite3_step(S)] has never before been called on S, 3408** then [sqlite3_reset(S)] returns [SQLITE_OK]. 3409** 3410** {F11336} If the most recent call to [sqlite3_step(S)] for 3411** [prepared statement] S indicated an error, then 3412** [sqlite3_reset(S)] returns an appropriate [error code]. 3413** 3414** {F11338} The [sqlite3_reset(S)] interface does not change the values 3415** of any [sqlite3_bind_blob|bindings] on [prepared statement] S. 3416*/ 3417int sqlite3_reset(sqlite3_stmt *pStmt); 3418 3419/* 3420** CAPI3REF: Create Or Redefine SQL Functions {F16100} 3421** KEYWORDS: {function creation routines} 3422** 3423** These two functions (collectively known as 3424** "function creation routines") are used to add SQL functions or aggregates 3425** or to redefine the behavior of existing SQL functions or aggregates. The 3426** difference only between the two is that the second parameter, the 3427** name of the (scalar) function or aggregate, is encoded in UTF-8 for 3428** sqlite3_create_function() and UTF-16 for sqlite3_create_function16(). 3429** 3430** The first parameter is the [database connection] to which the SQL 3431** function is to be added. If a single 3432** program uses more than one [database connection] internally, then SQL 3433** functions must be added individually to each [database connection]. 3434** 3435** The second parameter is the name of the SQL function to be created 3436** or redefined. 3437** The length of the name is limited to 255 bytes, exclusive of the 3438** zero-terminator. Note that the name length limit is in bytes, not 3439** characters. Any attempt to create a function with a longer name 3440** will result in an SQLITE_ERROR error. 3441** 3442** The third parameter is the number of arguments that the SQL function or 3443** aggregate takes. If this parameter is negative, then the SQL function or 3444** aggregate may take any number of arguments. 3445** 3446** The fourth parameter, eTextRep, specifies what 3447** [SQLITE_UTF8 | text encoding] this SQL function prefers for 3448** its parameters. Any SQL function implementation should be able to work 3449** work with UTF-8, UTF-16le, or UTF-16be. But some implementations may be 3450** more efficient with one encoding than another. It is allowed to 3451** invoke sqlite3_create_function() or sqlite3_create_function16() multiple 3452** times with the same function but with different values of eTextRep. 3453** When multiple implementations of the same function are available, SQLite 3454** will pick the one that involves the least amount of data conversion. 3455** If there is only a single implementation which does not care what 3456** text encoding is used, then the fourth argument should be 3457** [SQLITE_ANY]. 3458** 3459** The fifth parameter is an arbitrary pointer. The implementation 3460** of the function can gain access to this pointer using 3461** [sqlite3_user_data()]. 3462** 3463** The seventh, eighth and ninth parameters, xFunc, xStep and xFinal, are 3464** pointers to C-language functions that implement the SQL 3465** function or aggregate. A scalar SQL function requires an implementation of 3466** the xFunc callback only, NULL pointers should be passed as the xStep 3467** and xFinal parameters. An aggregate SQL function requires an implementation 3468** of xStep and xFinal and NULL should be passed for xFunc. To delete an 3469** existing SQL function or aggregate, pass NULL for all three function 3470** callback. 3471** 3472** It is permitted to register multiple implementations of the same 3473** functions with the same name but with either differing numbers of 3474** arguments or differing perferred text encodings. SQLite will use 3475** the implementation most closely matches the way in which the 3476** SQL function is used. 3477** 3478** INVARIANTS: 3479** 3480** {F16103} The [sqlite3_create_function16()] interface behaves exactly 3481** like [sqlite3_create_function()] in every way except that it 3482** interprets the zFunctionName argument as 3483** zero-terminated UTF-16 native byte order instead of as a 3484** zero-terminated UTF-8. 3485** 3486** {F16106} A successful invocation of 3487** the [sqlite3_create_function(D,X,N,E,...)] interface registers 3488** or replaces callback functions in [database connection] D 3489** used to implement the SQL function named X with N parameters 3490** and having a perferred text encoding of E. 3491** 3492** {F16109} A successful call to [sqlite3_create_function(D,X,N,E,P,F,S,L)] 3493** replaces the P, F, S, and L values from any prior calls with 3494** the same D, X, N, and E values. 3495** 3496** {F16112} The [sqlite3_create_function(D,X,...)] interface fails with 3497** a return code of [SQLITE_ERROR] if the SQL function name X is 3498** longer than 255 bytes exclusive of the zero terminator. 3499** 3500** {F16118} Either F must be NULL and S and L are non-NULL or else F 3501** is non-NULL and S and L are NULL, otherwise 3502** [sqlite3_create_function(D,X,N,E,P,F,S,L)] returns [SQLITE_ERROR]. 3503** 3504** {F16121} The [sqlite3_create_function(D,...)] interface fails with an 3505** error code of [SQLITE_BUSY] if there exist [prepared statements] 3506** associated with the [database connection] D. 3507** 3508** {F16124} The [sqlite3_create_function(D,X,N,...)] interface fails with an 3509** error code of [SQLITE_ERROR] if parameter N (specifying the number 3510** of arguments to the SQL function being registered) is less 3511** than -1 or greater than 127. 3512** 3513** {F16127} When N is non-negative, the [sqlite3_create_function(D,X,N,...)] 3514** interface causes callbacks to be invoked for the SQL function 3515** named X when the number of arguments to the SQL function is 3516** exactly N. 3517** 3518** {F16130} When N is -1, the [sqlite3_create_function(D,X,N,...)] 3519** interface causes callbacks to be invoked for the SQL function 3520** named X with any number of arguments. 3521** 3522** {F16133} When calls to [sqlite3_create_function(D,X,N,...)] 3523** specify multiple implementations of the same function X 3524** and when one implementation has N>=0 and the other has N=(-1) 3525** the implementation with a non-zero N is preferred. 3526** 3527** {F16136} When calls to [sqlite3_create_function(D,X,N,E,...)] 3528** specify multiple implementations of the same function X with 3529** the same number of arguments N but with different 3530** encodings E, then the implementation where E matches the 3531** database encoding is preferred. 3532** 3533** {F16139} For an aggregate SQL function created using 3534** [sqlite3_create_function(D,X,N,E,P,0,S,L)] the finializer 3535** function L will always be invoked exactly once if the 3536** step function S is called one or more times. 3537** 3538** {F16142} When SQLite invokes either the xFunc or xStep function of 3539** an application-defined SQL function or aggregate created 3540** by [sqlite3_create_function()] or [sqlite3_create_function16()], 3541** then the array of [sqlite3_value] objects passed as the 3542** third parameter are always [protected sqlite3_value] objects. 3543*/ 3544int sqlite3_create_function( 3545 sqlite3 *db, 3546 const char *zFunctionName, 3547 int nArg, 3548 int eTextRep, 3549 void *pApp, 3550 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 3551 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 3552 void (*xFinal)(sqlite3_context*) 3553); 3554int sqlite3_create_function16( 3555 sqlite3 *db, 3556 const void *zFunctionName, 3557 int nArg, 3558 int eTextRep, 3559 void *pApp, 3560 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 3561 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 3562 void (*xFinal)(sqlite3_context*) 3563); 3564 3565/* 3566** CAPI3REF: Text Encodings {F10267} 3567** 3568** These constant define integer codes that represent the various 3569** text encodings supported by SQLite. 3570*/ 3571#define SQLITE_UTF8 1 3572#define SQLITE_UTF16LE 2 3573#define SQLITE_UTF16BE 3 3574#define SQLITE_UTF16 4 /* Use native byte order */ 3575#define SQLITE_ANY 5 /* sqlite3_create_function only */ 3576#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 3577 3578/* 3579** CAPI3REF: Obsolete Functions 3580** 3581** These functions are all now obsolete. In order to maintain 3582** backwards compatibility with older code, we continue to support 3583** these functions. However, new development projects should avoid 3584** the use of these functions. To help encourage people to avoid 3585** using these functions, we are not going to tell you want they do. 3586*/ 3587int sqlite3_aggregate_count(sqlite3_context*); 3588int sqlite3_expired(sqlite3_stmt*); 3589int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 3590int sqlite3_global_recover(void); 3591void sqlite3_thread_cleanup(void); 3592int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),void*,sqlite3_int64); 3593 3594/* 3595** CAPI3REF: Obtaining SQL Function Parameter Values {F15100} 3596** 3597** The C-language implementation of SQL functions and aggregates uses 3598** this set of interface routines to access the parameter values on 3599** the function or aggregate. 3600** 3601** The xFunc (for scalar functions) or xStep (for aggregates) parameters 3602** to [sqlite3_create_function()] and [sqlite3_create_function16()] 3603** define callbacks that implement the SQL functions and aggregates. 3604** The 4th parameter to these callbacks is an array of pointers to 3605** [protected sqlite3_value] objects. There is one [sqlite3_value] object for 3606** each parameter to the SQL function. These routines are used to 3607** extract values from the [sqlite3_value] objects. 3608** 3609** These routines work only with [protected sqlite3_value] objects. 3610** Any attempt to use these routines on an [unprotected sqlite3_value] 3611** object results in undefined behavior. 3612** 3613** These routines work just like the corresponding 3614** [sqlite3_column_blob | sqlite3_column_* routines] except that 3615** these routines take a single [protected sqlite3_value] object pointer 3616** instead of an [sqlite3_stmt*] pointer and an integer column number. 3617** 3618** The sqlite3_value_text16() interface extracts a UTF16 string 3619** in the native byte-order of the host machine. The 3620** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 3621** extract UTF16 strings as big-endian and little-endian respectively. 3622** 3623** The sqlite3_value_numeric_type() interface attempts to apply 3624** numeric affinity to the value. This means that an attempt is 3625** made to convert the value to an integer or floating point. If 3626** such a conversion is possible without loss of information (in other 3627** words if the value is a string that looks like a number) 3628** then the conversion is done. Otherwise no conversion occurs. The 3629** [SQLITE_INTEGER | datatype] after conversion is returned. 3630** 3631** Please pay particular attention to the fact that the pointer that 3632** is returned from [sqlite3_value_blob()], [sqlite3_value_text()], or 3633** [sqlite3_value_text16()] can be invalidated by a subsequent call to 3634** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 3635** or [sqlite3_value_text16()]. 3636** 3637** These routines must be called from the same thread as 3638** the SQL function that supplied the [sqlite3_value*] parameters. 3639** 3640** 3641** INVARIANTS: 3642** 3643** {F15103} The [sqlite3_value_blob(V)] interface converts the 3644** [protected sqlite3_value] object V into a blob and then returns a 3645** pointer to the converted value. 3646** 3647** {F15106} The [sqlite3_value_bytes(V)] interface returns the 3648** number of bytes in the blob or string (exclusive of the 3649** zero terminator on the string) that was returned by the 3650** most recent call to [sqlite3_value_blob(V)] or 3651** [sqlite3_value_text(V)]. 3652** 3653** {F15109} The [sqlite3_value_bytes16(V)] interface returns the 3654** number of bytes in the string (exclusive of the 3655** zero terminator on the string) that was returned by the 3656** most recent call to [sqlite3_value_text16(V)], 3657** [sqlite3_value_text16be(V)], or [sqlite3_value_text16le(V)]. 3658** 3659** {F15112} The [sqlite3_value_double(V)] interface converts the 3660** [protected sqlite3_value] object V into a floating point value and 3661** returns a copy of that value. 3662** 3663** {F15115} The [sqlite3_value_int(V)] interface converts the 3664** [protected sqlite3_value] object V into a 64-bit signed integer and 3665** returns the lower 32 bits of that integer. 3666** 3667** {F15118} The [sqlite3_value_int64(V)] interface converts the 3668** [protected sqlite3_value] object V into a 64-bit signed integer and 3669** returns a copy of that integer. 3670** 3671** {F15121} The [sqlite3_value_text(V)] interface converts the 3672** [protected sqlite3_value] object V into a zero-terminated UTF-8 3673** string and returns a pointer to that string. 3674** 3675** {F15124} The [sqlite3_value_text16(V)] interface converts the 3676** [protected sqlite3_value] object V into a zero-terminated 2-byte 3677** aligned UTF-16 native byte order 3678** string and returns a pointer to that string. 3679** 3680** {F15127} The [sqlite3_value_text16be(V)] interface converts the 3681** [protected sqlite3_value] object V into a zero-terminated 2-byte 3682** aligned UTF-16 big-endian 3683** string and returns a pointer to that string. 3684** 3685** {F15130} The [sqlite3_value_text16le(V)] interface converts the 3686** [protected sqlite3_value] object V into a zero-terminated 2-byte 3687** aligned UTF-16 little-endian 3688** string and returns a pointer to that string. 3689** 3690** {F15133} The [sqlite3_value_type(V)] interface returns 3691** one of [SQLITE_NULL], [SQLITE_INTEGER], [SQLITE_FLOAT], 3692** [SQLITE_TEXT], or [SQLITE_BLOB] as appropriate for 3693** the [sqlite3_value] object V. 3694** 3695** {F15136} The [sqlite3_value_numeric_type(V)] interface converts 3696** the [protected sqlite3_value] object V into either an integer or 3697** a floating point value if it can do so without loss of 3698** information, and returns one of [SQLITE_NULL], 3699** [SQLITE_INTEGER], [SQLITE_FLOAT], [SQLITE_TEXT], or 3700** [SQLITE_BLOB] as appropriate for 3701** the [protected sqlite3_value] object V after the conversion attempt. 3702*/ 3703const void *sqlite3_value_blob(sqlite3_value*); 3704int sqlite3_value_bytes(sqlite3_value*); 3705int sqlite3_value_bytes16(sqlite3_value*); 3706double sqlite3_value_double(sqlite3_value*); 3707int sqlite3_value_int(sqlite3_value*); 3708sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 3709const unsigned char *sqlite3_value_text(sqlite3_value*); 3710const void *sqlite3_value_text16(sqlite3_value*); 3711const void *sqlite3_value_text16le(sqlite3_value*); 3712const void *sqlite3_value_text16be(sqlite3_value*); 3713int sqlite3_value_type(sqlite3_value*); 3714int sqlite3_value_numeric_type(sqlite3_value*); 3715 3716/* 3717** CAPI3REF: Obtain Aggregate Function Context {F16210} 3718** 3719** The implementation of aggregate SQL functions use this routine to allocate 3720** a structure for storing their state. 3721** The first time the sqlite3_aggregate_context() routine is 3722** is called for a particular aggregate, SQLite allocates nBytes of memory 3723** zeros that memory, and returns a pointer to it. 3724** On second and subsequent calls to sqlite3_aggregate_context() 3725** for the same aggregate function index, the same buffer is returned. 3726** The implementation 3727** of the aggregate can use the returned buffer to accumulate data. 3728** 3729** SQLite automatically frees the allocated buffer when the aggregate 3730** query concludes. 3731** 3732** The first parameter should be a copy of the 3733** [sqlite3_context | SQL function context] that is the first 3734** parameter to the callback routine that implements the aggregate 3735** function. 3736** 3737** This routine must be called from the same thread in which 3738** the aggregate SQL function is running. 3739** 3740** INVARIANTS: 3741** 3742** {F16211} The first invocation of [sqlite3_aggregate_context(C,N)] for 3743** a particular instance of an aggregate function (for a particular 3744** context C) causes SQLite to allocation N bytes of memory, 3745** zero that memory, and return a pointer to the allocationed 3746** memory. 3747** 3748** {F16213} If a memory allocation error occurs during 3749** [sqlite3_aggregate_context(C,N)] then the function returns 0. 3750** 3751** {F16215} Second and subsequent invocations of 3752** [sqlite3_aggregate_context(C,N)] for the same context pointer C 3753** ignore the N parameter and return a pointer to the same 3754** block of memory returned by the first invocation. 3755** 3756** {F16217} The memory allocated by [sqlite3_aggregate_context(C,N)] is 3757** automatically freed on the next call to [sqlite3_reset()] 3758** or [sqlite3_finalize()] for the [prepared statement] containing 3759** the aggregate function associated with context C. 3760*/ 3761void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 3762 3763/* 3764** CAPI3REF: User Data For Functions {F16240} 3765** 3766** The sqlite3_user_data() interface returns a copy of 3767** the pointer that was the pUserData parameter (the 5th parameter) 3768** of the the [sqlite3_create_function()] 3769** and [sqlite3_create_function16()] routines that originally 3770** registered the application defined function. {END} 3771** 3772** This routine must be called from the same thread in which 3773** the application-defined function is running. 3774** 3775** INVARIANTS: 3776** 3777** {F16243} The [sqlite3_user_data(C)] interface returns a copy of the 3778** P pointer from the [sqlite3_create_function(D,X,N,E,P,F,S,L)] 3779** or [sqlite3_create_function16(D,X,N,E,P,F,S,L)] call that 3780** registered the SQL function associated with 3781** [sqlite3_context] C. 3782*/ 3783void *sqlite3_user_data(sqlite3_context*); 3784 3785/* 3786** CAPI3REF: Database Connection For Functions {F16250} 3787** 3788** The sqlite3_context_db_handle() interface returns a copy of 3789** the pointer to the [database connection] (the 1st parameter) 3790** of the the [sqlite3_create_function()] 3791** and [sqlite3_create_function16()] routines that originally 3792** registered the application defined function. 3793** 3794** INVARIANTS: 3795** 3796** {F16253} The [sqlite3_context_db_handle(C)] interface returns a copy of the 3797** D pointer from the [sqlite3_create_function(D,X,N,E,P,F,S,L)] 3798** or [sqlite3_create_function16(D,X,N,E,P,F,S,L)] call that 3799** registered the SQL function associated with 3800** [sqlite3_context] C. 3801*/ 3802sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 3803 3804/* 3805** CAPI3REF: Function Auxiliary Data {F16270} 3806** 3807** The following two functions may be used by scalar SQL functions to 3808** associate meta-data with argument values. If the same value is passed to 3809** multiple invocations of the same SQL function during query execution, under 3810** some circumstances the associated meta-data may be preserved. This may 3811** be used, for example, to add a regular-expression matching scalar 3812** function. The compiled version of the regular expression is stored as 3813** meta-data associated with the SQL value passed as the regular expression 3814** pattern. The compiled regular expression can be reused on multiple 3815** invocations of the same function so that the original pattern string 3816** does not need to be recompiled on each invocation. 3817** 3818** The sqlite3_get_auxdata() interface returns a pointer to the meta-data 3819** associated by the sqlite3_set_auxdata() function with the Nth argument 3820** value to the application-defined function. 3821** If no meta-data has been ever been set for the Nth 3822** argument of the function, or if the cooresponding function parameter 3823** has changed since the meta-data was set, then sqlite3_get_auxdata() 3824** returns a NULL pointer. 3825** 3826** The sqlite3_set_auxdata() interface saves the meta-data 3827** pointed to by its 3rd parameter as the meta-data for the N-th 3828** argument of the application-defined function. Subsequent 3829** calls to sqlite3_get_auxdata() might return this data, if it has 3830** not been destroyed. 3831** If it is not NULL, SQLite will invoke the destructor 3832** function given by the 4th parameter to sqlite3_set_auxdata() on 3833** the meta-data when the corresponding function parameter changes 3834** or when the SQL statement completes, whichever comes first. 3835** 3836** SQLite is free to call the destructor and drop meta-data on 3837** any parameter of any function at any time. The only guarantee 3838** is that the destructor will be called before the metadata is 3839** dropped. 3840** 3841** In practice, meta-data is preserved between function calls for 3842** expressions that are constant at compile time. This includes literal 3843** values and SQL variables. 3844** 3845** These routines must be called from the same thread in which 3846** the SQL function is running. 3847** 3848** INVARIANTS: 3849** 3850** {F16272} The [sqlite3_get_auxdata(C,N)] interface returns a pointer 3851** to metadata associated with the Nth parameter of the SQL function 3852** whose context is C, or NULL if there is no metadata associated 3853** with that parameter. 3854** 3855** {F16274} The [sqlite3_set_auxdata(C,N,P,D)] interface assigns a metadata 3856** pointer P to the Nth parameter of the SQL function with context 3857** C. 3858** 3859** {F16276} SQLite will invoke the destructor D with a single argument 3860** which is the metadata pointer P following a call to 3861** [sqlite3_set_auxdata(C,N,P,D)] when SQLite ceases to hold 3862** the metadata. 3863** 3864** {F16277} SQLite ceases to hold metadata for an SQL function parameter 3865** when the value of that parameter changes. 3866** 3867** {F16278} When [sqlite3_set_auxdata(C,N,P,D)] is invoked, the destructor 3868** is called for any prior metadata associated with the same function 3869** context C and parameter N. 3870** 3871** {F16279} SQLite will call destructors for any metadata it is holding 3872** in a particular [prepared statement] S when either 3873** [sqlite3_reset(S)] or [sqlite3_finalize(S)] is called. 3874*/ 3875void *sqlite3_get_auxdata(sqlite3_context*, int N); 3876void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 3877 3878 3879/* 3880** CAPI3REF: Constants Defining Special Destructor Behavior {F10280} 3881** 3882** These are special value for the destructor that is passed in as the 3883** final argument to routines like [sqlite3_result_blob()]. If the destructor 3884** argument is SQLITE_STATIC, it means that the content pointer is constant 3885** and will never change. It does not need to be destroyed. The 3886** SQLITE_TRANSIENT value means that the content will likely change in 3887** the near future and that SQLite should make its own private copy of 3888** the content before returning. 3889** 3890** The typedef is necessary to work around problems in certain 3891** C++ compilers. See ticket #2191. 3892*/ 3893typedef void (*sqlite3_destructor_type)(void*); 3894#define SQLITE_STATIC ((sqlite3_destructor_type)0) 3895#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 3896 3897/* 3898** CAPI3REF: Setting The Result Of An SQL Function {F16400} 3899** 3900** These routines are used by the xFunc or xFinal callbacks that 3901** implement SQL functions and aggregates. See 3902** [sqlite3_create_function()] and [sqlite3_create_function16()] 3903** for additional information. 3904** 3905** These functions work very much like the 3906** [sqlite3_bind_blob | sqlite3_bind_*] family of functions used 3907** to bind values to host parameters in prepared statements. 3908** Refer to the 3909** [sqlite3_bind_blob | sqlite3_bind_* documentation] for 3910** additional information. 3911** 3912** The sqlite3_result_blob() interface sets the result from 3913** an application defined function to be the BLOB whose content is pointed 3914** to by the second parameter and which is N bytes long where N is the 3915** third parameter. 3916** The sqlite3_result_zeroblob() inerfaces set the result of 3917** the application defined function to be a BLOB containing all zero 3918** bytes and N bytes in size, where N is the value of the 2nd parameter. 3919** 3920** The sqlite3_result_double() interface sets the result from 3921** an application defined function to be a floating point value specified 3922** by its 2nd argument. 3923** 3924** The sqlite3_result_error() and sqlite3_result_error16() functions 3925** cause the implemented SQL function to throw an exception. 3926** SQLite uses the string pointed to by the 3927** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 3928** as the text of an error message. SQLite interprets the error 3929** message string from sqlite3_result_error() as UTF8. SQLite 3930** interprets the string from sqlite3_result_error16() as UTF16 in native 3931** byte order. If the third parameter to sqlite3_result_error() 3932** or sqlite3_result_error16() is negative then SQLite takes as the error 3933** message all text up through the first zero character. 3934** If the third parameter to sqlite3_result_error() or 3935** sqlite3_result_error16() is non-negative then SQLite takes that many 3936** bytes (not characters) from the 2nd parameter as the error message. 3937** The sqlite3_result_error() and sqlite3_result_error16() 3938** routines make a copy private copy of the error message text before 3939** they return. Hence, the calling function can deallocate or 3940** modify the text after they return without harm. 3941** The sqlite3_result_error_code() function changes the error code 3942** returned by SQLite as a result of an error in a function. By default, 3943** the error code is SQLITE_ERROR. A subsequent call to sqlite3_result_error() 3944** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 3945** 3946** The sqlite3_result_toobig() interface causes SQLite 3947** to throw an error indicating that a string or BLOB is to long 3948** to represent. The sqlite3_result_nomem() interface 3949** causes SQLite to throw an exception indicating that the a 3950** memory allocation failed. 3951** 3952** The sqlite3_result_int() interface sets the return value 3953** of the application-defined function to be the 32-bit signed integer 3954** value given in the 2nd argument. 3955** The sqlite3_result_int64() interface sets the return value 3956** of the application-defined function to be the 64-bit signed integer 3957** value given in the 2nd argument. 3958** 3959** The sqlite3_result_null() interface sets the return value 3960** of the application-defined function to be NULL. 3961** 3962** The sqlite3_result_text(), sqlite3_result_text16(), 3963** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 3964** set the return value of the application-defined function to be 3965** a text string which is represented as UTF-8, UTF-16 native byte order, 3966** UTF-16 little endian, or UTF-16 big endian, respectively. 3967** SQLite takes the text result from the application from 3968** the 2nd parameter of the sqlite3_result_text* interfaces. 3969** If the 3rd parameter to the sqlite3_result_text* interfaces 3970** is negative, then SQLite takes result text from the 2nd parameter 3971** through the first zero character. 3972** If the 3rd parameter to the sqlite3_result_text* interfaces 3973** is non-negative, then as many bytes (not characters) of the text 3974** pointed to by the 2nd parameter are taken as the application-defined 3975** function result. 3976** If the 4th parameter to the sqlite3_result_text* interfaces 3977** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 3978** function as the destructor on the text or blob result when it has 3979** finished using that result. 3980** If the 4th parameter to the sqlite3_result_text* interfaces 3981** or sqlite3_result_blob is the special constant SQLITE_STATIC, then 3982** SQLite assumes that the text or blob result is constant space and 3983** does not copy the space or call a destructor when it has 3984** finished using that result. 3985** If the 4th parameter to the sqlite3_result_text* interfaces 3986** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 3987** then SQLite makes a copy of the result into space obtained from 3988** from [sqlite3_malloc()] before it returns. 3989** 3990** The sqlite3_result_value() interface sets the result of 3991** the application-defined function to be a copy the 3992** [unprotected sqlite3_value] object specified by the 2nd parameter. The 3993** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 3994** so that [sqlite3_value] specified in the parameter may change or 3995** be deallocated after sqlite3_result_value() returns without harm. 3996** A [protected sqlite3_value] object may always be used where an 3997** [unprotected sqlite3_value] object is required, so either 3998** kind of [sqlite3_value] object can be used with this interface. 3999** 4000** If these routines are called from within the different thread 4001** than the one containing the application-defined function that recieved 4002** the [sqlite3_context] pointer, the results are undefined. 4003** 4004** INVARIANTS: 4005** 4006** {F16403} The default return value from any SQL function is NULL. 4007** 4008** {F16406} The [sqlite3_result_blob(C,V,N,D)] interface changes the 4009** return value of function C to be a blob that is N bytes 4010** in length and with content pointed to by V. 4011** 4012** {F16409} The [sqlite3_result_double(C,V)] interface changes the 4013** return value of function C to be the floating point value V. 4014** 4015** {F16412} The [sqlite3_result_error(C,V,N)] interface changes the return 4016** value of function C to be an exception with error code 4017** [SQLITE_ERROR] and a UTF8 error message copied from V up to the 4018** first zero byte or until N bytes are read if N is positive. 4019** 4020** {F16415} The [sqlite3_result_error16(C,V,N)] interface changes the return 4021** value of function C to be an exception with error code 4022** [SQLITE_ERROR] and a UTF16 native byte order error message 4023** copied from V up to the first zero terminator or until N bytes 4024** are read if N is positive. 4025** 4026** {F16418} The [sqlite3_result_error_toobig(C)] interface changes the return 4027** value of the function C to be an exception with error code 4028** [SQLITE_TOOBIG] and an appropriate error message. 4029** 4030** {F16421} The [sqlite3_result_error_nomem(C)] interface changes the return 4031** value of the function C to be an exception with error code 4032** [SQLITE_NOMEM] and an appropriate error message. 4033** 4034** {F16424} The [sqlite3_result_error_code(C,E)] interface changes the return 4035** value of the function C to be an exception with error code E. 4036** The error message text is unchanged. 4037** 4038** {F16427} The [sqlite3_result_int(C,V)] interface changes the 4039** return value of function C to be the 32-bit integer value V. 4040** 4041** {F16430} The [sqlite3_result_int64(C,V)] interface changes the 4042** return value of function C to be the 64-bit integer value V. 4043** 4044** {F16433} The [sqlite3_result_null(C)] interface changes the 4045** return value of function C to be NULL. 4046** 4047** {F16436} The [sqlite3_result_text(C,V,N,D)] interface changes the 4048** return value of function C to be the UTF8 string 4049** V up to the first zero if N is negative 4050** or the first N bytes of V if N is non-negative. 4051** 4052** {F16439} The [sqlite3_result_text16(C,V,N,D)] interface changes the 4053** return value of function C to be the UTF16 native byte order 4054** string V up to the first zero if N is 4055** negative or the first N bytes of V if N is non-negative. 4056** 4057** {F16442} The [sqlite3_result_text16be(C,V,N,D)] interface changes the 4058** return value of function C to be the UTF16 big-endian 4059** string V up to the first zero if N is 4060** is negative or the first N bytes or V if N is non-negative. 4061** 4062** {F16445} The [sqlite3_result_text16le(C,V,N,D)] interface changes the 4063** return value of function C to be the UTF16 little-endian 4064** string V up to the first zero if N is 4065** negative or the first N bytes of V if N is non-negative. 4066** 4067** {F16448} The [sqlite3_result_value(C,V)] interface changes the 4068** return value of function C to be [unprotected sqlite3_value] 4069** object V. 4070** 4071** {F16451} The [sqlite3_result_zeroblob(C,N)] interface changes the 4072** return value of function C to be an N-byte blob of all zeros. 4073** 4074** {F16454} The [sqlite3_result_error()] and [sqlite3_result_error16()] 4075** interfaces make a copy of their error message strings before 4076** returning. 4077** 4078** {F16457} If the D destructor parameter to [sqlite3_result_blob(C,V,N,D)], 4079** [sqlite3_result_text(C,V,N,D)], [sqlite3_result_text16(C,V,N,D)], 4080** [sqlite3_result_text16be(C,V,N,D)], or 4081** [sqlite3_result_text16le(C,V,N,D)] is the constant [SQLITE_STATIC] 4082** then no destructor is ever called on the pointer V and SQLite 4083** assumes that V is immutable. 4084** 4085** {F16460} If the D destructor parameter to [sqlite3_result_blob(C,V,N,D)], 4086** [sqlite3_result_text(C,V,N,D)], [sqlite3_result_text16(C,V,N,D)], 4087** [sqlite3_result_text16be(C,V,N,D)], or 4088** [sqlite3_result_text16le(C,V,N,D)] is the constant 4089** [SQLITE_TRANSIENT] then the interfaces makes a copy of the 4090** content of V and retains the copy. 4091** 4092** {F16463} If the D destructor parameter to [sqlite3_result_blob(C,V,N,D)], 4093** [sqlite3_result_text(C,V,N,D)], [sqlite3_result_text16(C,V,N,D)], 4094** [sqlite3_result_text16be(C,V,N,D)], or 4095** [sqlite3_result_text16le(C,V,N,D)] is some value other than 4096** the constants [SQLITE_STATIC] and [SQLITE_TRANSIENT] then 4097** SQLite will invoke the destructor D with V as its only argument 4098** when it has finished with the V value. 4099*/ 4100void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 4101void sqlite3_result_double(sqlite3_context*, double); 4102void sqlite3_result_error(sqlite3_context*, const char*, int); 4103void sqlite3_result_error16(sqlite3_context*, const void*, int); 4104void sqlite3_result_error_toobig(sqlite3_context*); 4105void sqlite3_result_error_nomem(sqlite3_context*); 4106void sqlite3_result_error_code(sqlite3_context*, int); 4107void sqlite3_result_int(sqlite3_context*, int); 4108void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 4109void sqlite3_result_null(sqlite3_context*); 4110void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 4111void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 4112void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 4113void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 4114void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 4115void sqlite3_result_zeroblob(sqlite3_context*, int n); 4116 4117/* 4118** CAPI3REF: Define New Collating Sequences {F16600} 4119** 4120** These functions are used to add new collation sequences to the 4121** [sqlite3*] handle specified as the first argument. 4122** 4123** The name of the new collation sequence is specified as a UTF-8 string 4124** for sqlite3_create_collation() and sqlite3_create_collation_v2() 4125** and a UTF-16 string for sqlite3_create_collation16(). In all cases 4126** the name is passed as the second function argument. 4127** 4128** The third argument may be one of the constants [SQLITE_UTF8], 4129** [SQLITE_UTF16LE] or [SQLITE_UTF16BE], indicating that the user-supplied 4130** routine expects to be passed pointers to strings encoded using UTF-8, 4131** UTF-16 little-endian or UTF-16 big-endian respectively. The 4132** third argument might also be [SQLITE_UTF16_ALIGNED] to indicate that 4133** the routine expects pointers to 16-bit word aligned strings 4134** of UTF16 in the native byte order of the host computer. 4135** 4136** A pointer to the user supplied routine must be passed as the fifth 4137** argument. If it is NULL, this is the same as deleting the collation 4138** sequence (so that SQLite cannot call it anymore). 4139** Each time the application 4140** supplied function is invoked, it is passed a copy of the void* passed as 4141** the fourth argument to sqlite3_create_collation() or 4142** sqlite3_create_collation16() as its first parameter. 4143** 4144** The remaining arguments to the application-supplied routine are two strings, 4145** each represented by a (length, data) pair and encoded in the encoding 4146** that was passed as the third argument when the collation sequence was 4147** registered. {END} The application defined collation routine should 4148** return negative, zero or positive if 4149** the first string is less than, equal to, or greater than the second 4150** string. i.e. (STRING1 - STRING2). 4151** 4152** The sqlite3_create_collation_v2() works like sqlite3_create_collation() 4153** excapt that it takes an extra argument which is a destructor for 4154** the collation. The destructor is called when the collation is 4155** destroyed and is passed a copy of the fourth parameter void* pointer 4156** of the sqlite3_create_collation_v2(). 4157** Collations are destroyed when 4158** they are overridden by later calls to the collation creation functions 4159** or when the [sqlite3*] database handle is closed using [sqlite3_close()]. 4160** 4161** INVARIANTS: 4162** 4163** {F16603} A successful call to the 4164** [sqlite3_create_collation_v2(B,X,E,P,F,D)] interface 4165** registers function F as the comparison function used to 4166** implement collation X on [database connection] B for 4167** databases having encoding E. 4168** 4169** {F16604} SQLite understands the X parameter to 4170** [sqlite3_create_collation_v2(B,X,E,P,F,D)] as a zero-terminated 4171** UTF-8 string in which case is ignored for ASCII characters and 4172** is significant for non-ASCII characters. 4173** 4174** {F16606} Successive calls to [sqlite3_create_collation_v2(B,X,E,P,F,D)] 4175** with the same values for B, X, and E, override prior values 4176** of P, F, and D. 4177** 4178** {F16609} The destructor D in [sqlite3_create_collation_v2(B,X,E,P,F,D)] 4179** is not NULL then it is called with argument P when the 4180** collating function is dropped by SQLite. 4181** 4182** {F16612} A collating function is dropped when it is overloaded. 4183** 4184** {F16615} A collating function is dropped when the database connection 4185** is closed using [sqlite3_close()]. 4186** 4187** {F16618} The pointer P in [sqlite3_create_collation_v2(B,X,E,P,F,D)] 4188** is passed through as the first parameter to the comparison 4189** function F for all subsequent invocations of F. 4190** 4191** {F16621} A call to [sqlite3_create_collation(B,X,E,P,F)] is exactly 4192** the same as a call to [sqlite3_create_collation_v2()] with 4193** the same parameters and a NULL destructor. 4194** 4195** {F16624} Following a [sqlite3_create_collation_v2(B,X,E,P,F,D)], 4196** SQLite uses the comparison function F for all text comparison 4197** operations on [database connection] B on text values that 4198** use the collating sequence name X. 4199** 4200** {F16627} The [sqlite3_create_collation16(B,X,E,P,F)] works the same 4201** as [sqlite3_create_collation(B,X,E,P,F)] except that the 4202** collation name X is understood as UTF-16 in native byte order 4203** instead of UTF-8. 4204** 4205** {F16630} When multiple comparison functions are available for the same 4206** collating sequence, SQLite chooses the one whose text encoding 4207** requires the least amount of conversion from the default 4208** text encoding of the database. 4209*/ 4210int sqlite3_create_collation( 4211 sqlite3*, 4212 const char *zName, 4213 int eTextRep, 4214 void*, 4215 int(*xCompare)(void*,int,const void*,int,const void*) 4216); 4217int sqlite3_create_collation_v2( 4218 sqlite3*, 4219 const char *zName, 4220 int eTextRep, 4221 void*, 4222 int(*xCompare)(void*,int,const void*,int,const void*), 4223 void(*xDestroy)(void*) 4224); 4225int sqlite3_create_collation16( 4226 sqlite3*, 4227 const char *zName, 4228 int eTextRep, 4229 void*, 4230 int(*xCompare)(void*,int,const void*,int,const void*) 4231); 4232 4233/* 4234** CAPI3REF: Collation Needed Callbacks {F16700} 4235** 4236** To avoid having to register all collation sequences before a database 4237** can be used, a single callback function may be registered with the 4238** database handle to be called whenever an undefined collation sequence is 4239** required. 4240** 4241** If the function is registered using the sqlite3_collation_needed() API, 4242** then it is passed the names of undefined collation sequences as strings 4243** encoded in UTF-8. {F16703} If sqlite3_collation_needed16() is used, the names 4244** are passed as UTF-16 in machine native byte order. A call to either 4245** function replaces any existing callback. 4246** 4247** When the callback is invoked, the first argument passed is a copy 4248** of the second argument to sqlite3_collation_needed() or 4249** sqlite3_collation_needed16(). The second argument is the database 4250** handle. The third argument is one of [SQLITE_UTF8], 4251** [SQLITE_UTF16BE], or [SQLITE_UTF16LE], indicating the most 4252** desirable form of the collation sequence function required. 4253** The fourth parameter is the name of the 4254** required collation sequence. 4255** 4256** The callback function should register the desired collation using 4257** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 4258** [sqlite3_create_collation_v2()]. 4259** 4260** INVARIANTS: 4261** 4262** {F16702} A successful call to [sqlite3_collation_needed(D,P,F)] 4263** or [sqlite3_collation_needed16(D,P,F)] causes 4264** the [database connection] D to invoke callback F with first 4265** parameter P whenever it needs a comparison function for a 4266** collating sequence that it does not know about. 4267** 4268** {F16704} Each successful call to [sqlite3_collation_needed()] or 4269** [sqlite3_collation_needed16()] overrides the callback registered 4270** on the same [database connection] by prior calls to either 4271** interface. 4272** 4273** {F16706} The name of the requested collating function passed in the 4274** 4th parameter to the callback is in UTF-8 if the callback 4275** was registered using [sqlite3_collation_needed()] and 4276** is in UTF-16 native byte order if the callback was 4277** registered using [sqlite3_collation_needed16()]. 4278** 4279** 4280*/ 4281int sqlite3_collation_needed( 4282 sqlite3*, 4283 void*, 4284 void(*)(void*,sqlite3*,int eTextRep,const char*) 4285); 4286int sqlite3_collation_needed16( 4287 sqlite3*, 4288 void*, 4289 void(*)(void*,sqlite3*,int eTextRep,const void*) 4290); 4291 4292/* 4293** Specify the key for an encrypted database. This routine should be 4294** called right after sqlite3_open(). 4295** 4296** The code to implement this API is not available in the public release 4297** of SQLite. 4298*/ 4299int sqlite3_key( 4300 sqlite3 *db, /* Database to be rekeyed */ 4301 const void *pKey, int nKey /* The key */ 4302); 4303 4304/* 4305** Change the key on an open database. If the current database is not 4306** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 4307** database is decrypted. 4308** 4309** The code to implement this API is not available in the public release 4310** of SQLite. 4311*/ 4312int sqlite3_rekey( 4313 sqlite3 *db, /* Database to be rekeyed */ 4314 const void *pKey, int nKey /* The new key */ 4315); 4316 4317/* 4318** CAPI3REF: Suspend Execution For A Short Time {F10530} 4319** 4320** The sqlite3_sleep() function 4321** causes the current thread to suspend execution 4322** for at least a number of milliseconds specified in its parameter. 4323** 4324** If the operating system does not support sleep requests with 4325** millisecond time resolution, then the time will be rounded up to 4326** the nearest second. The number of milliseconds of sleep actually 4327** requested from the operating system is returned. 4328** 4329** SQLite implements this interface by calling the xSleep() 4330** method of the default [sqlite3_vfs] object. 4331** 4332** INVARIANTS: 4333** 4334** {F10533} The [sqlite3_sleep(M)] interface invokes the xSleep 4335** method of the default [sqlite3_vfs|VFS] in order to 4336** suspend execution of the current thread for at least 4337** M milliseconds. 4338** 4339** {F10536} The [sqlite3_sleep(M)] interface returns the number of 4340** milliseconds of sleep actually requested of the operating 4341** system, which might be larger than the parameter M. 4342*/ 4343int sqlite3_sleep(int); 4344 4345/* 4346** CAPI3REF: Name Of The Folder Holding Temporary Files {F10310} 4347** 4348** If this global variable is made to point to a string which is 4349** the name of a folder (a.ka. directory), then all temporary files 4350** created by SQLite will be placed in that directory. If this variable 4351** is NULL pointer, then SQLite does a search for an appropriate temporary 4352** file directory. 4353** 4354** It is not safe to modify this variable once a database connection 4355** has been opened. It is intended that this variable be set once 4356** as part of process initialization and before any SQLite interface 4357** routines have been call and remain unchanged thereafter. 4358*/ 4359SQLITE_EXTERN char *sqlite3_temp_directory; 4360 4361/* 4362** CAPI3REF: Test To See If The Database Is In Auto-Commit Mode {F12930} 4363** 4364** The sqlite3_get_autocommit() interfaces returns non-zero or 4365** zero if the given database connection is or is not in autocommit mode, 4366** respectively. Autocommit mode is on 4367** by default. Autocommit mode is disabled by a [BEGIN] statement. 4368** Autocommit mode is reenabled by a [COMMIT] or [ROLLBACK]. 4369** 4370** If certain kinds of errors occur on a statement within a multi-statement 4371** transactions (errors including [SQLITE_FULL], [SQLITE_IOERR], 4372** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 4373** transaction might be rolled back automatically. The only way to 4374** find out if SQLite automatically rolled back the transaction after 4375** an error is to use this function. 4376** 4377** INVARIANTS: 4378** 4379** {F12931} The [sqlite3_get_autocommit(D)] interface returns non-zero or 4380** zero if the [database connection] D is or is not in autocommit 4381** mode, respectively. 4382** 4383** {F12932} Autocommit mode is on by default. 4384** 4385** {F12933} Autocommit mode is disabled by a successful [BEGIN] statement. 4386** 4387** {F12934} Autocommit mode is enabled by a successful [COMMIT] or [ROLLBACK] 4388** statement. 4389** 4390** 4391** LIMITATIONS: 4392*** 4393** {U12936} If another thread changes the autocommit status of the database 4394** connection while this routine is running, then the return value 4395** is undefined. 4396*/ 4397int sqlite3_get_autocommit(sqlite3*); 4398 4399/* 4400** CAPI3REF: Find The Database Handle Of A Prepared Statement {F13120} 4401** 4402** The sqlite3_db_handle interface 4403** returns the [sqlite3*] database handle to which a 4404** [prepared statement] belongs. 4405** The database handle returned by sqlite3_db_handle 4406** is the same database handle that was 4407** the first argument to the [sqlite3_prepare_v2()] or its variants 4408** that was used to create the statement in the first place. 4409** 4410** INVARIANTS: 4411** 4412** {F13123} The [sqlite3_db_handle(S)] interface returns a pointer 4413** to the [database connection] associated with 4414** [prepared statement] S. 4415*/ 4416sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 4417 4418 4419/* 4420** CAPI3REF: Commit And Rollback Notification Callbacks {F12950} 4421** 4422** The sqlite3_commit_hook() interface registers a callback 4423** function to be invoked whenever a transaction is committed. 4424** Any callback set by a previous call to sqlite3_commit_hook() 4425** for the same database connection is overridden. 4426** The sqlite3_rollback_hook() interface registers a callback 4427** function to be invoked whenever a transaction is committed. 4428** Any callback set by a previous call to sqlite3_commit_hook() 4429** for the same database connection is overridden. 4430** The pArg argument is passed through 4431** to the callback. If the callback on a commit hook function 4432** returns non-zero, then the commit is converted into a rollback. 4433** 4434** If another function was previously registered, its 4435** pArg value is returned. Otherwise NULL is returned. 4436** 4437** Registering a NULL function disables the callback. 4438** 4439** For the purposes of this API, a transaction is said to have been 4440** rolled back if an explicit "ROLLBACK" statement is executed, or 4441** an error or constraint causes an implicit rollback to occur. 4442** The rollback callback is not invoked if a transaction is 4443** automatically rolled back because the database connection is closed. 4444** The rollback callback is not invoked if a transaction is 4445** rolled back because a commit callback returned non-zero. 4446** <todo> Check on this </todo> 4447** 4448** These are experimental interfaces and are subject to change. 4449** 4450** INVARIANTS: 4451** 4452** {F12951} The [sqlite3_commit_hook(D,F,P)] interface registers the 4453** callback function F to be invoked with argument P whenever 4454** a transaction commits on [database connection] D. 4455** 4456** {F12952} The [sqlite3_commit_hook(D,F,P)] interface returns the P 4457** argument from the previous call with the same 4458** [database connection ] D , or NULL on the first call 4459** for a particular [database connection] D. 4460** 4461** {F12953} Each call to [sqlite3_commit_hook()] overwrites the callback 4462** registered by prior calls. 4463** 4464** {F12954} If the F argument to [sqlite3_commit_hook(D,F,P)] is NULL 4465** then the commit hook callback is cancelled and no callback 4466** is invoked when a transaction commits. 4467** 4468** {F12955} If the commit callback returns non-zero then the commit is 4469** converted into a rollback. 4470** 4471** {F12961} The [sqlite3_rollback_hook(D,F,P)] interface registers the 4472** callback function F to be invoked with argument P whenever 4473** a transaction rolls back on [database connection] D. 4474** 4475** {F12962} The [sqlite3_rollback_hook(D,F,P)] interface returns the P 4476** argument from the previous call with the same 4477** [database connection ] D , or NULL on the first call 4478** for a particular [database connection] D. 4479** 4480** {F12963} Each call to [sqlite3_rollback_hook()] overwrites the callback 4481** registered by prior calls. 4482** 4483** {F12964} If the F argument to [sqlite3_rollback_hook(D,F,P)] is NULL 4484** then the rollback hook callback is cancelled and no callback 4485** is invoked when a transaction rolls back. 4486*/ 4487void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 4488void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 4489 4490/* 4491** CAPI3REF: Data Change Notification Callbacks {F12970} 4492** 4493** The sqlite3_update_hook() interface 4494** registers a callback function with the database connection identified by the 4495** first argument to be invoked whenever a row is updated, inserted or deleted. 4496** Any callback set by a previous call to this function for the same 4497** database connection is overridden. 4498** 4499** The second argument is a pointer to the function to invoke when a 4500** row is updated, inserted or deleted. 4501** The first argument to the callback is 4502** a copy of the third argument to sqlite3_update_hook(). 4503** The second callback 4504** argument is one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], 4505** depending on the operation that caused the callback to be invoked. 4506** The third and 4507** fourth arguments to the callback contain pointers to the database and 4508** table name containing the affected row. 4509** The final callback parameter is 4510** the rowid of the row. 4511** In the case of an update, this is the rowid after 4512** the update takes place. 4513** 4514** The update hook is not invoked when internal system tables are 4515** modified (i.e. sqlite_master and sqlite_sequence). 4516** 4517** If another function was previously registered, its pArg value 4518** is returned. Otherwise NULL is returned. 4519** 4520** INVARIANTS: 4521** 4522** {F12971} The [sqlite3_update_hook(D,F,P)] interface causes callback 4523** function F to be invoked with first parameter P whenever 4524** a table row is modified, inserted, or deleted on 4525** [database connection] D. 4526** 4527** {F12973} The [sqlite3_update_hook(D,F,P)] interface returns the value 4528** of P for the previous call on the same [database connection] D, 4529** or NULL for the first call. 4530** 4531** {F12975} If the update hook callback F in [sqlite3_update_hook(D,F,P)] 4532** is NULL then the no update callbacks are made. 4533** 4534** {F12977} Each call to [sqlite3_update_hook(D,F,P)] overrides prior calls 4535** to the same interface on the same [database connection] D. 4536** 4537** {F12979} The update hook callback is not invoked when internal system 4538** tables such as sqlite_master and sqlite_sequence are modified. 4539** 4540** {F12981} The second parameter to the update callback 4541** is one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], 4542** depending on the operation that caused the callback to be invoked. 4543** 4544** {F12983} The third and fourth arguments to the callback contain pointers 4545** to zero-terminated UTF-8 strings which are the names of the 4546** database and table that is being updated. 4547 4548** {F12985} The final callback parameter is the rowid of the row after 4549** the change occurs. 4550*/ 4551void *sqlite3_update_hook( 4552 sqlite3*, 4553 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 4554 void* 4555); 4556 4557/* 4558** CAPI3REF: Enable Or Disable Shared Pager Cache {F10330} 4559** 4560** This routine enables or disables the sharing of the database cache 4561** and schema data structures between connections to the same database. 4562** Sharing is enabled if the argument is true and disabled if the argument 4563** is false. 4564** 4565** Cache sharing is enabled and disabled 4566** for an entire process. {END} This is a change as of SQLite version 3.5.0. 4567** In prior versions of SQLite, sharing was 4568** enabled or disabled for each thread separately. 4569** 4570** The cache sharing mode set by this interface effects all subsequent 4571** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 4572** Existing database connections continue use the sharing mode 4573** that was in effect at the time they were opened. 4574** 4575** Virtual tables cannot be used with a shared cache. When shared 4576** cache is enabled, the [sqlite3_create_module()] API used to register 4577** virtual tables will always return an error. 4578** 4579** This routine returns [SQLITE_OK] if shared cache was 4580** enabled or disabled successfully. An [error code] 4581** is returned otherwise. 4582** 4583** Shared cache is disabled by default. But this might change in 4584** future releases of SQLite. Applications that care about shared 4585** cache setting should set it explicitly. 4586** 4587** INVARIANTS: 4588** 4589** {F10331} A successful invocation of [sqlite3_enable_shared_cache(B)] 4590** will enable or disable shared cache mode for any subsequently 4591** created [database connection] in the same process. 4592** 4593** {F10336} When shared cache is enabled, the [sqlite3_create_module()] 4594** interface will always return an error. 4595** 4596** {F10337} The [sqlite3_enable_shared_cache(B)] interface returns 4597** [SQLITE_OK] if shared cache was enabled or disabled successfully. 4598** 4599** {F10339} Shared cache is disabled by default. 4600*/ 4601int sqlite3_enable_shared_cache(int); 4602 4603/* 4604** CAPI3REF: Attempt To Free Heap Memory {F17340} 4605** 4606** The sqlite3_release_memory() interface attempts to 4607** free N bytes of heap memory by deallocating non-essential memory 4608** allocations held by the database labrary. {END} Memory used 4609** to cache database pages to improve performance is an example of 4610** non-essential memory. Sqlite3_release_memory() returns 4611** the number of bytes actually freed, which might be more or less 4612** than the amount requested. 4613** 4614** INVARIANTS: 4615** 4616** {F17341} The [sqlite3_release_memory(N)] interface attempts to 4617** free N bytes of heap memory by deallocating non-essential 4618** memory allocations held by the database labrary. 4619** 4620** {F16342} The [sqlite3_release_memory(N)] returns the number 4621** of bytes actually freed, which might be more or less 4622** than the amount requested. 4623*/ 4624int sqlite3_release_memory(int); 4625 4626/* 4627** CAPI3REF: Impose A Limit On Heap Size {F17350} 4628** 4629** The sqlite3_soft_heap_limit() interface 4630** places a "soft" limit on the amount of heap memory that may be allocated 4631** by SQLite. If an internal allocation is requested 4632** that would exceed the soft heap limit, [sqlite3_release_memory()] is 4633** invoked one or more times to free up some space before the allocation 4634** is made. 4635** 4636** The limit is called "soft", because if 4637** [sqlite3_release_memory()] cannot 4638** free sufficient memory to prevent the limit from being exceeded, 4639** the memory is allocated anyway and the current operation proceeds. 4640** 4641** A negative or zero value for N means that there is no soft heap limit and 4642** [sqlite3_release_memory()] will only be called when memory is exhausted. 4643** The default value for the soft heap limit is zero. 4644** 4645** SQLite makes a best effort to honor the soft heap limit. 4646** But if the soft heap limit cannot honored, execution will 4647** continue without error or notification. This is why the limit is 4648** called a "soft" limit. It is advisory only. 4649** 4650** Prior to SQLite version 3.5.0, this routine only constrained the memory 4651** allocated by a single thread - the same thread in which this routine 4652** runs. Beginning with SQLite version 3.5.0, the soft heap limit is 4653** applied to all threads. The value specified for the soft heap limit 4654** is an upper bound on the total memory allocation for all threads. In 4655** version 3.5.0 there is no mechanism for limiting the heap usage for 4656** individual threads. 4657** 4658** INVARIANTS: 4659** 4660** {F16351} The [sqlite3_soft_heap_limit(N)] interface places a soft limit 4661** of N bytes on the amount of heap memory that may be allocated 4662** using [sqlite3_malloc()] or [sqlite3_realloc()] at any point 4663** in time. 4664** 4665** {F16352} If a call to [sqlite3_malloc()] or [sqlite3_realloc()] would 4666** cause the total amount of allocated memory to exceed the 4667** soft heap limit, then [sqlite3_release_memory()] is invoked 4668** in an attempt to reduce the memory usage prior to proceeding 4669** with the memory allocation attempt. 4670** 4671** {F16353} Calls to [sqlite3_malloc()] or [sqlite3_realloc()] that trigger 4672** attempts to reduce memory usage through the soft heap limit 4673** mechanism continue even if the attempt to reduce memory 4674** usage is unsuccessful. 4675** 4676** {F16354} A negative or zero value for N in a call to 4677** [sqlite3_soft_heap_limit(N)] means that there is no soft 4678** heap limit and [sqlite3_release_memory()] will only be 4679** called when memory is completely exhausted. 4680** 4681** {F16355} The default value for the soft heap limit is zero. 4682** 4683** {F16358} Each call to [sqlite3_soft_heap_limit(N)] overrides the 4684** values set by all prior calls. 4685*/ 4686void sqlite3_soft_heap_limit(int); 4687 4688/* 4689** CAPI3REF: Extract Metadata About A Column Of A Table {F12850} 4690** 4691** This routine 4692** returns meta-data about a specific column of a specific database 4693** table accessible using the connection handle passed as the first function 4694** argument. 4695** 4696** The column is identified by the second, third and fourth parameters to 4697** this function. The second parameter is either the name of the database 4698** (i.e. "main", "temp" or an attached database) containing the specified 4699** table or NULL. If it is NULL, then all attached databases are searched 4700** for the table using the same algorithm as the database engine uses to 4701** resolve unqualified table references. 4702** 4703** The third and fourth parameters to this function are the table and column 4704** name of the desired column, respectively. Neither of these parameters 4705** may be NULL. 4706** 4707** Meta information is returned by writing to the memory locations passed as 4708** the 5th and subsequent parameters to this function. Any of these 4709** arguments may be NULL, in which case the corresponding element of meta 4710** information is ommitted. 4711** 4712** <pre> 4713** Parameter Output Type Description 4714** ----------------------------------- 4715** 4716** 5th const char* Data type 4717** 6th const char* Name of the default collation sequence 4718** 7th int True if the column has a NOT NULL constraint 4719** 8th int True if the column is part of the PRIMARY KEY 4720** 9th int True if the column is AUTOINCREMENT 4721** </pre> 4722** 4723** 4724** The memory pointed to by the character pointers returned for the 4725** declaration type and collation sequence is valid only until the next 4726** call to any sqlite API function. 4727** 4728** If the specified table is actually a view, then an error is returned. 4729** 4730** If the specified column is "rowid", "oid" or "_rowid_" and an 4731** INTEGER PRIMARY KEY column has been explicitly declared, then the output 4732** parameters are set for the explicitly declared column. If there is no 4733** explicitly declared IPK column, then the output parameters are set as 4734** follows: 4735** 4736** <pre> 4737** data type: "INTEGER" 4738** collation sequence: "BINARY" 4739** not null: 0 4740** primary key: 1 4741** auto increment: 0 4742** </pre> 4743** 4744** This function may load one or more schemas from database files. If an 4745** error occurs during this process, or if the requested table or column 4746** cannot be found, an SQLITE error code is returned and an error message 4747** left in the database handle (to be retrieved using sqlite3_errmsg()). 4748** 4749** This API is only available if the library was compiled with the 4750** SQLITE_ENABLE_COLUMN_METADATA preprocessor symbol defined. 4751*/ 4752int sqlite3_table_column_metadata( 4753 sqlite3 *db, /* Connection handle */ 4754 const char *zDbName, /* Database name or NULL */ 4755 const char *zTableName, /* Table name */ 4756 const char *zColumnName, /* Column name */ 4757 char const **pzDataType, /* OUTPUT: Declared data type */ 4758 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 4759 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 4760 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 4761 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 4762); 4763 4764/* 4765** CAPI3REF: Load An Extension {F12600} 4766** 4767** {F12601} The sqlite3_load_extension() interface 4768** attempts to load an SQLite extension library contained in the file 4769** zFile. {F12602} The entry point is zProc. {F12603} zProc may be 0 4770** in which case the name of the entry point defaults 4771** to "sqlite3_extension_init". 4772** 4773** {F12604} The sqlite3_load_extension() interface shall 4774** return [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 4775** 4776** {F12605} 4777** If an error occurs and pzErrMsg is not 0, then the 4778** sqlite3_load_extension() interface shall attempt to fill *pzErrMsg with 4779** error message text stored in memory obtained from [sqlite3_malloc()]. 4780** {END} The calling function should free this memory 4781** by calling [sqlite3_free()]. 4782** 4783** {F12606} 4784** Extension loading must be enabled using [sqlite3_enable_load_extension()] 4785** prior to calling this API or an error will be returned. 4786*/ 4787int sqlite3_load_extension( 4788 sqlite3 *db, /* Load the extension into this database connection */ 4789 const char *zFile, /* Name of the shared library containing extension */ 4790 const char *zProc, /* Entry point. Derived from zFile if 0 */ 4791 char **pzErrMsg /* Put error message here if not 0 */ 4792); 4793 4794/* 4795** CAPI3REF: Enable Or Disable Extension Loading {F12620} 4796** 4797** So as not to open security holes in older applications that are 4798** unprepared to deal with extension loading, and as a means of disabling 4799** extension loading while evaluating user-entered SQL, the following 4800** API is provided to turn the [sqlite3_load_extension()] mechanism on and 4801** off. {F12622} It is off by default. {END} See ticket #1863. 4802** 4803** {F12621} Call the sqlite3_enable_load_extension() routine 4804** with onoff==1 to turn extension loading on 4805** and call it with onoff==0 to turn it back off again. {END} 4806*/ 4807int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 4808 4809/* 4810** CAPI3REF: Make Arrangements To Automatically Load An Extension {F12640} 4811** 4812** {F12641} This function 4813** registers an extension entry point that is automatically invoked 4814** whenever a new database connection is opened using 4815** [sqlite3_open()], [sqlite3_open16()], or [sqlite3_open_v2()]. {END} 4816** 4817** This API can be invoked at program startup in order to register 4818** one or more statically linked extensions that will be available 4819** to all new database connections. 4820** 4821** {F12642} Duplicate extensions are detected so calling this routine multiple 4822** times with the same extension is harmless. 4823** 4824** {F12643} This routine stores a pointer to the extension in an array 4825** that is obtained from sqlite_malloc(). {END} If you run a memory leak 4826** checker on your program and it reports a leak because of this 4827** array, then invoke [sqlite3_reset_auto_extension()] prior 4828** to shutdown to free the memory. 4829** 4830** {F12644} Automatic extensions apply across all threads. {END} 4831** 4832** This interface is experimental and is subject to change or 4833** removal in future releases of SQLite. 4834*/ 4835int sqlite3_auto_extension(void *xEntryPoint); 4836 4837 4838/* 4839** CAPI3REF: Reset Automatic Extension Loading {F12660} 4840** 4841** {F12661} This function disables all previously registered 4842** automatic extensions. {END} This 4843** routine undoes the effect of all prior [sqlite3_auto_extension()] 4844** calls. 4845** 4846** {F12662} This call disabled automatic extensions in all threads. {END} 4847** 4848** This interface is experimental and is subject to change or 4849** removal in future releases of SQLite. 4850*/ 4851void sqlite3_reset_auto_extension(void); 4852 4853 4854/* 4855****** EXPERIMENTAL - subject to change without notice ************** 4856** 4857** The interface to the virtual-table mechanism is currently considered 4858** to be experimental. The interface might change in incompatible ways. 4859** If this is a problem for you, do not use the interface at this time. 4860** 4861** When the virtual-table mechanism stablizes, we will declare the 4862** interface fixed, support it indefinitely, and remove this comment. 4863*/ 4864 4865/* 4866** Structures used by the virtual table interface 4867*/ 4868typedef struct sqlite3_vtab sqlite3_vtab; 4869typedef struct sqlite3_index_info sqlite3_index_info; 4870typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 4871typedef struct sqlite3_module sqlite3_module; 4872 4873/* 4874** CAPI3REF: Virtual Table Object {F18000} 4875** KEYWORDS: sqlite3_module 4876** 4877** A module is a class of virtual tables. Each module is defined 4878** by an instance of the following structure. This structure consists 4879** mostly of methods for the module. 4880*/ 4881struct sqlite3_module { 4882 int iVersion; 4883 int (*xCreate)(sqlite3*, void *pAux, 4884 int argc, const char *const*argv, 4885 sqlite3_vtab **ppVTab, char**); 4886 int (*xConnect)(sqlite3*, void *pAux, 4887 int argc, const char *const*argv, 4888 sqlite3_vtab **ppVTab, char**); 4889 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 4890 int (*xDisconnect)(sqlite3_vtab *pVTab); 4891 int (*xDestroy)(sqlite3_vtab *pVTab); 4892 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 4893 int (*xClose)(sqlite3_vtab_cursor*); 4894 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 4895 int argc, sqlite3_value **argv); 4896 int (*xNext)(sqlite3_vtab_cursor*); 4897 int (*xEof)(sqlite3_vtab_cursor*); 4898 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 4899 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 4900 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 4901 int (*xBegin)(sqlite3_vtab *pVTab); 4902 int (*xSync)(sqlite3_vtab *pVTab); 4903 int (*xCommit)(sqlite3_vtab *pVTab); 4904 int (*xRollback)(sqlite3_vtab *pVTab); 4905 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 4906 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 4907 void **ppArg); 4908 4909 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 4910}; 4911 4912/* 4913** CAPI3REF: Virtual Table Indexing Information {F18100} 4914** KEYWORDS: sqlite3_index_info 4915** 4916** The sqlite3_index_info structure and its substructures is used to 4917** pass information into and receive the reply from the xBestIndex 4918** method of an sqlite3_module. The fields under **Inputs** are the 4919** inputs to xBestIndex and are read-only. xBestIndex inserts its 4920** results into the **Outputs** fields. 4921** 4922** The aConstraint[] array records WHERE clause constraints of the 4923** form: 4924** 4925** column OP expr 4926** 4927** Where OP is =, <, <=, >, or >=. 4928** The particular operator is stored 4929** in aConstraint[].op. The index of the column is stored in 4930** aConstraint[].iColumn. aConstraint[].usable is TRUE if the 4931** expr on the right-hand side can be evaluated (and thus the constraint 4932** is usable) and false if it cannot. 4933** 4934** The optimizer automatically inverts terms of the form "expr OP column" 4935** and makes other simplifications to the WHERE clause in an attempt to 4936** get as many WHERE clause terms into the form shown above as possible. 4937** The aConstraint[] array only reports WHERE clause terms in the correct 4938** form that refer to the particular virtual table being queried. 4939** 4940** Information about the ORDER BY clause is stored in aOrderBy[]. 4941** Each term of aOrderBy records a column of the ORDER BY clause. 4942** 4943** The xBestIndex method must fill aConstraintUsage[] with information 4944** about what parameters to pass to xFilter. If argvIndex>0 then 4945** the right-hand side of the corresponding aConstraint[] is evaluated 4946** and becomes the argvIndex-th entry in argv. If aConstraintUsage[].omit 4947** is true, then the constraint is assumed to be fully handled by the 4948** virtual table and is not checked again by SQLite. 4949** 4950** The idxNum and idxPtr values are recorded and passed into xFilter. 4951** sqlite3_free() is used to free idxPtr if needToFreeIdxPtr is true. 4952** 4953** The orderByConsumed means that output from xFilter will occur in 4954** the correct order to satisfy the ORDER BY clause so that no separate 4955** sorting step is required. 4956** 4957** The estimatedCost value is an estimate of the cost of doing the 4958** particular lookup. A full scan of a table with N entries should have 4959** a cost of N. A binary search of a table of N entries should have a 4960** cost of approximately log(N). 4961*/ 4962struct sqlite3_index_info { 4963 /* Inputs */ 4964 int nConstraint; /* Number of entries in aConstraint */ 4965 struct sqlite3_index_constraint { 4966 int iColumn; /* Column on left-hand side of constraint */ 4967 unsigned char op; /* Constraint operator */ 4968 unsigned char usable; /* True if this constraint is usable */ 4969 int iTermOffset; /* Used internally - xBestIndex should ignore */ 4970 } *aConstraint; /* Table of WHERE clause constraints */ 4971 int nOrderBy; /* Number of terms in the ORDER BY clause */ 4972 struct sqlite3_index_orderby { 4973 int iColumn; /* Column number */ 4974 unsigned char desc; /* True for DESC. False for ASC. */ 4975 } *aOrderBy; /* The ORDER BY clause */ 4976 4977 /* Outputs */ 4978 struct sqlite3_index_constraint_usage { 4979 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 4980 unsigned char omit; /* Do not code a test for this constraint */ 4981 } *aConstraintUsage; 4982 int idxNum; /* Number used to identify the index */ 4983 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 4984 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 4985 int orderByConsumed; /* True if output is already ordered */ 4986 double estimatedCost; /* Estimated cost of using this index */ 4987}; 4988#define SQLITE_INDEX_CONSTRAINT_EQ 2 4989#define SQLITE_INDEX_CONSTRAINT_GT 4 4990#define SQLITE_INDEX_CONSTRAINT_LE 8 4991#define SQLITE_INDEX_CONSTRAINT_LT 16 4992#define SQLITE_INDEX_CONSTRAINT_GE 32 4993#define SQLITE_INDEX_CONSTRAINT_MATCH 64 4994 4995/* 4996** CAPI3REF: Register A Virtual Table Implementation {F18200} 4997** 4998** This routine is used to register a new module name with an SQLite 4999** connection. Module names must be registered before creating new 5000** virtual tables on the module, or before using preexisting virtual 5001** tables of the module. 5002*/ 5003int sqlite3_create_module( 5004 sqlite3 *db, /* SQLite connection to register module with */ 5005 const char *zName, /* Name of the module */ 5006 const sqlite3_module *, /* Methods for the module */ 5007 void * /* Client data for xCreate/xConnect */ 5008); 5009 5010/* 5011** CAPI3REF: Register A Virtual Table Implementation {F18210} 5012** 5013** This routine is identical to the sqlite3_create_module() method above, 5014** except that it allows a destructor function to be specified. It is 5015** even more experimental than the rest of the virtual tables API. 5016*/ 5017int sqlite3_create_module_v2( 5018 sqlite3 *db, /* SQLite connection to register module with */ 5019 const char *zName, /* Name of the module */ 5020 const sqlite3_module *, /* Methods for the module */ 5021 void *, /* Client data for xCreate/xConnect */ 5022 void(*xDestroy)(void*) /* Module destructor function */ 5023); 5024 5025/* 5026** CAPI3REF: Virtual Table Instance Object {F18010} 5027** KEYWORDS: sqlite3_vtab 5028** 5029** Every module implementation uses a subclass of the following structure 5030** to describe a particular instance of the module. Each subclass will 5031** be tailored to the specific needs of the module implementation. The 5032** purpose of this superclass is to define certain fields that are common 5033** to all module implementations. 5034** 5035** Virtual tables methods can set an error message by assigning a 5036** string obtained from sqlite3_mprintf() to zErrMsg. The method should 5037** take care that any prior string is freed by a call to sqlite3_free() 5038** prior to assigning a new string to zErrMsg. After the error message 5039** is delivered up to the client application, the string will be automatically 5040** freed by sqlite3_free() and the zErrMsg field will be zeroed. Note 5041** that sqlite3_mprintf() and sqlite3_free() are used on the zErrMsg field 5042** since virtual tables are commonly implemented in loadable extensions which 5043** do not have access to sqlite3MPrintf() or sqlite3Free(). 5044*/ 5045struct sqlite3_vtab { 5046 const sqlite3_module *pModule; /* The module for this virtual table */ 5047 int nRef; /* Used internally */ 5048 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 5049 /* Virtual table implementations will typically add additional fields */ 5050}; 5051 5052/* 5053** CAPI3REF: Virtual Table Cursor Object {F18020} 5054** KEYWORDS: sqlite3_vtab_cursor 5055** 5056** Every module implementation uses a subclass of the following structure 5057** to describe cursors that point into the virtual table and are used 5058** to loop through the virtual table. Cursors are created using the 5059** xOpen method of the module. Each module implementation will define 5060** the content of a cursor structure to suit its own needs. 5061** 5062** This superclass exists in order to define fields of the cursor that 5063** are common to all implementations. 5064*/ 5065struct sqlite3_vtab_cursor { 5066 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 5067 /* Virtual table implementations will typically add additional fields */ 5068}; 5069 5070/* 5071** CAPI3REF: Declare The Schema Of A Virtual Table {F18280} 5072** 5073** The xCreate and xConnect methods of a module use the following API 5074** to declare the format (the names and datatypes of the columns) of 5075** the virtual tables they implement. 5076*/ 5077int sqlite3_declare_vtab(sqlite3*, const char *zCreateTable); 5078 5079/* 5080** CAPI3REF: Overload A Function For A Virtual Table {F18300} 5081** 5082** Virtual tables can provide alternative implementations of functions 5083** using the xFindFunction method. But global versions of those functions 5084** must exist in order to be overloaded. 5085** 5086** This API makes sure a global version of a function with a particular 5087** name and number of parameters exists. If no such function exists 5088** before this API is called, a new function is created. The implementation 5089** of the new function always causes an exception to be thrown. So 5090** the new function is not good for anything by itself. Its only 5091** purpose is to be a place-holder function that can be overloaded 5092** by virtual tables. 5093** 5094** This API should be considered part of the virtual table interface, 5095** which is experimental and subject to change. 5096*/ 5097int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 5098 5099/* 5100** The interface to the virtual-table mechanism defined above (back up 5101** to a comment remarkably similar to this one) is currently considered 5102** to be experimental. The interface might change in incompatible ways. 5103** If this is a problem for you, do not use the interface at this time. 5104** 5105** When the virtual-table mechanism stabilizes, we will declare the 5106** interface fixed, support it indefinitely, and remove this comment. 5107** 5108****** EXPERIMENTAL - subject to change without notice ************** 5109*/ 5110 5111/* 5112** CAPI3REF: A Handle To An Open BLOB {F17800} 5113** 5114** An instance of this object represents an open BLOB on which 5115** incremental I/O can be preformed. 5116** Objects of this type are created by 5117** [sqlite3_blob_open()] and destroyed by [sqlite3_blob_close()]. 5118** The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 5119** can be used to read or write small subsections of the blob. 5120** The [sqlite3_blob_bytes()] interface returns the size of the 5121** blob in bytes. 5122*/ 5123typedef struct sqlite3_blob sqlite3_blob; 5124 5125/* 5126** CAPI3REF: Open A BLOB For Incremental I/O {F17810} 5127** 5128** This interfaces opens a handle to the blob located 5129** in row iRow, column zColumn, table zTable in database zDb; 5130** in other words, the same blob that would be selected by: 5131** 5132** <pre> 5133** SELECT zColumn FROM zDb.zTable WHERE rowid = iRow; 5134** </pre> {END} 5135** 5136** If the flags parameter is non-zero, the blob is opened for 5137** read and write access. If it is zero, the blob is opened for read 5138** access. 5139** 5140** Note that the database name is not the filename that contains 5141** the database but rather the symbolic name of the database that 5142** is assigned when the database is connected using [ATTACH]. 5143** For the main database file, the database name is "main". For 5144** TEMP tables, the database name is "temp". 5145** 5146** On success, [SQLITE_OK] is returned and the new 5147** [sqlite3_blob | blob handle] is written to *ppBlob. 5148** Otherwise an error code is returned and 5149** any value written to *ppBlob should not be used by the caller. 5150** This function sets the database-handle error code and message 5151** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()]. 5152** 5153** INVARIANTS: 5154** 5155** {F17813} A successful invocation of the [sqlite3_blob_open(D,B,T,C,R,F,P)] 5156** interface opens an [sqlite3_blob] object P on the blob 5157** in column C of table T in database B on [database connection] D. 5158** 5159** {F17814} A successful invocation of [sqlite3_blob_open(D,...)] starts 5160** a new transaction on [database connection] D if that connection 5161** is not already in a transaction. 5162** 5163** {F17816} The [sqlite3_blob_open(D,B,T,C,R,F,P)] interface opens the blob 5164** for read and write access if and only if the F parameter 5165** is non-zero. 5166** 5167** {F17819} The [sqlite3_blob_open()] interface returns [SQLITE_OK] on 5168** success and an appropriate [error code] on failure. 5169** 5170** {F17821} If an error occurs during evaluation of [sqlite3_blob_open(D,...)] 5171** then subsequent calls to [sqlite3_errcode(D)], 5172** [sqlite3_errmsg(D)], and [sqlite3_errmsg16(D)] will return 5173** information approprate for that error. 5174*/ 5175int sqlite3_blob_open( 5176 sqlite3*, 5177 const char *zDb, 5178 const char *zTable, 5179 const char *zColumn, 5180 sqlite3_int64 iRow, 5181 int flags, 5182 sqlite3_blob **ppBlob 5183); 5184 5185/* 5186** CAPI3REF: Close A BLOB Handle {F17830} 5187** 5188** Close an open [sqlite3_blob | blob handle]. 5189** 5190** Closing a BLOB shall cause the current transaction to commit 5191** if there are no other BLOBs, no pending prepared statements, and the 5192** database connection is in autocommit mode. 5193** If any writes were made to the BLOB, they might be held in cache 5194** until the close operation if they will fit. {END} 5195** Closing the BLOB often forces the changes 5196** out to disk and so if any I/O errors occur, they will likely occur 5197** at the time when the BLOB is closed. {F17833} Any errors that occur during 5198** closing are reported as a non-zero return value. 5199** 5200** The BLOB is closed unconditionally. Even if this routine returns 5201** an error code, the BLOB is still closed. 5202** 5203** INVARIANTS: 5204** 5205** {F17833} The [sqlite3_blob_close(P)] interface closes an 5206** [sqlite3_blob] object P previously opened using 5207** [sqlite3_blob_open()]. 5208** 5209** {F17836} Closing an [sqlite3_blob] object using 5210** [sqlite3_blob_close()] shall cause the current transaction to 5211** commit if there are no other open [sqlite3_blob] objects 5212** or [prepared statements] on the same [database connection] and 5213** the [database connection] is in 5214** [sqlite3_get_autocommit | autocommit mode]. 5215** 5216** {F17839} The [sqlite3_blob_close(P)] interfaces closes the 5217** [sqlite3_blob] object P unconditionally, even if 5218** [sqlite3_blob_close(P)] returns something other than [SQLITE_OK]. 5219** 5220*/ 5221int sqlite3_blob_close(sqlite3_blob *); 5222 5223/* 5224** CAPI3REF: Return The Size Of An Open BLOB {F17840} 5225** 5226** Return the size in bytes of the blob accessible via the open 5227** [sqlite3_blob] object in its only argument. 5228** 5229** INVARIANTS: 5230** 5231** {F17843} The [sqlite3_blob_bytes(P)] interface returns the size 5232** in bytes of the BLOB that the [sqlite3_blob] object P 5233** refers to. 5234*/ 5235int sqlite3_blob_bytes(sqlite3_blob *); 5236 5237/* 5238** CAPI3REF: Read Data From A BLOB Incrementally {F17850} 5239** 5240** This function is used to read data from an open 5241** [sqlite3_blob | blob-handle] into a caller supplied buffer. 5242** N bytes of data are copied into buffer 5243** Z from the open blob, starting at offset iOffset. 5244** 5245** If offset iOffset is less than N bytes from the end of the blob, 5246** [SQLITE_ERROR] is returned and no data is read. If N or iOffset is 5247** less than zero [SQLITE_ERROR] is returned and no data is read. 5248** 5249** On success, SQLITE_OK is returned. Otherwise, an 5250** [error code] or an [extended error code] is returned. 5251** 5252** INVARIANTS: 5253** 5254** {F17853} The [sqlite3_blob_read(P,Z,N,X)] interface reads N bytes 5255** beginning at offset X from 5256** the blob that [sqlite3_blob] object P refers to 5257** and writes those N bytes into buffer Z. 5258** 5259** {F17856} In [sqlite3_blob_read(P,Z,N,X)] if the size of the blob 5260** is less than N+X bytes, then the function returns [SQLITE_ERROR] 5261** and nothing is read from the blob. 5262** 5263** {F17859} In [sqlite3_blob_read(P,Z,N,X)] if X or N is less than zero 5264** then the function returns [SQLITE_ERROR] 5265** and nothing is read from the blob. 5266** 5267** {F17862} The [sqlite3_blob_read(P,Z,N,X)] interface returns [SQLITE_OK] 5268** if N bytes where successfully read into buffer Z. 5269** 5270** {F17865} If the requested read could not be completed, 5271** the [sqlite3_blob_read(P,Z,N,X)] interface returns an 5272** appropriate [error code] or [extended error code]. 5273** 5274** {F17868} If an error occurs during evaluation of [sqlite3_blob_read(P,...)] 5275** then subsequent calls to [sqlite3_errcode(D)], 5276** [sqlite3_errmsg(D)], and [sqlite3_errmsg16(D)] will return 5277** information approprate for that error, where D is the 5278** database handle that was used to open blob handle P. 5279*/ 5280int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 5281 5282/* 5283** CAPI3REF: Write Data Into A BLOB Incrementally {F17870} 5284** 5285** This function is used to write data into an open 5286** [sqlite3_blob | blob-handle] from a user supplied buffer. 5287** n bytes of data are copied from the buffer 5288** pointed to by z into the open blob, starting at offset iOffset. 5289** 5290** If the [sqlite3_blob | blob-handle] passed as the first argument 5291** was not opened for writing (the flags parameter to [sqlite3_blob_open()] 5292*** was zero), this function returns [SQLITE_READONLY]. 5293** 5294** This function may only modify the contents of the blob; it is 5295** not possible to increase the size of a blob using this API. 5296** If offset iOffset is less than n bytes from the end of the blob, 5297** [SQLITE_ERROR] is returned and no data is written. If n is 5298** less than zero [SQLITE_ERROR] is returned and no data is written. 5299** 5300** On success, SQLITE_OK is returned. Otherwise, an 5301** [error code] or an [extended error code] is returned. 5302** 5303** INVARIANTS: 5304** 5305** {F17873} The [sqlite3_blob_write(P,Z,N,X)] interface writes N bytes 5306** from buffer Z into 5307** the blob that [sqlite3_blob] object P refers to 5308** beginning at an offset of X into the blob. 5309** 5310** {F17875} The [sqlite3_blob_write(P,Z,N,X)] interface returns 5311** [SQLITE_READONLY] if the [sqlite3_blob] object P was 5312** [sqlite3_blob_open | opened] for reading only. 5313** 5314** {F17876} In [sqlite3_blob_write(P,Z,N,X)] if the size of the blob 5315** is less than N+X bytes, then the function returns [SQLITE_ERROR] 5316** and nothing is written into the blob. 5317** 5318** {F17879} In [sqlite3_blob_write(P,Z,N,X)] if X or N is less than zero 5319** then the function returns [SQLITE_ERROR] 5320** and nothing is written into the blob. 5321** 5322** {F17882} The [sqlite3_blob_write(P,Z,N,X)] interface returns [SQLITE_OK] 5323** if N bytes where successfully written into blob. 5324** 5325** {F17885} If the requested write could not be completed, 5326** the [sqlite3_blob_write(P,Z,N,X)] interface returns an 5327** appropriate [error code] or [extended error code]. 5328** 5329** {F17888} If an error occurs during evaluation of [sqlite3_blob_write(D,...)] 5330** then subsequent calls to [sqlite3_errcode(D)], 5331** [sqlite3_errmsg(D)], and [sqlite3_errmsg16(D)] will return 5332** information approprate for that error. 5333*/ 5334int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 5335 5336/* 5337** CAPI3REF: Virtual File System Objects {F11200} 5338** 5339** A virtual filesystem (VFS) is an [sqlite3_vfs] object 5340** that SQLite uses to interact 5341** with the underlying operating system. Most SQLite builds come with a 5342** single default VFS that is appropriate for the host computer. 5343** New VFSes can be registered and existing VFSes can be unregistered. 5344** The following interfaces are provided. 5345** 5346** The sqlite3_vfs_find() interface returns a pointer to 5347** a VFS given its name. Names are case sensitive. 5348** Names are zero-terminated UTF-8 strings. 5349** If there is no match, a NULL 5350** pointer is returned. If zVfsName is NULL then the default 5351** VFS is returned. 5352** 5353** New VFSes are registered with sqlite3_vfs_register(). 5354** Each new VFS becomes the default VFS if the makeDflt flag is set. 5355** The same VFS can be registered multiple times without injury. 5356** To make an existing VFS into the default VFS, register it again 5357** with the makeDflt flag set. If two different VFSes with the 5358** same name are registered, the behavior is undefined. If a 5359** VFS is registered with a name that is NULL or an empty string, 5360** then the behavior is undefined. 5361** 5362** Unregister a VFS with the sqlite3_vfs_unregister() interface. 5363** If the default VFS is unregistered, another VFS is chosen as 5364** the default. The choice for the new VFS is arbitrary. 5365** 5366** INVARIANTS: 5367** 5368** {F11203} The [sqlite3_vfs_find(N)] interface returns a pointer to the 5369** registered [sqlite3_vfs] object whose name exactly matches 5370** the zero-terminated UTF-8 string N, or it returns NULL if 5371** there is no match. 5372** 5373** {F11206} If the N parameter to [sqlite3_vfs_find(N)] is NULL then 5374** the function returns a pointer to the default [sqlite3_vfs] 5375** object if there is one, or NULL if there is no default 5376** [sqlite3_vfs] object. 5377** 5378** {F11209} The [sqlite3_vfs_register(P,F)] interface registers the 5379** well-formed [sqlite3_vfs] object P using the name given 5380** by the zName field of the object. 5381** 5382** {F11212} Using the [sqlite3_vfs_register(P,F)] interface to register 5383** the same [sqlite3_vfs] object multiple times is a harmless no-op. 5384** 5385** {F11215} The [sqlite3_vfs_register(P,F)] interface makes the 5386** the [sqlite3_vfs] object P the default [sqlite3_vfs] object 5387** if F is non-zero. 5388** 5389** {F11218} The [sqlite3_vfs_unregister(P)] interface unregisters the 5390** [sqlite3_vfs] object P so that it is no longer returned by 5391** subsequent calls to [sqlite3_vfs_find()]. 5392*/ 5393sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 5394int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 5395int sqlite3_vfs_unregister(sqlite3_vfs*); 5396 5397/* 5398** CAPI3REF: Mutexes {F17000} 5399** 5400** The SQLite core uses these routines for thread 5401** synchronization. Though they are intended for internal 5402** use by SQLite, code that links against SQLite is 5403** permitted to use any of these routines. 5404** 5405** The SQLite source code contains multiple implementations 5406** of these mutex routines. An appropriate implementation 5407** is selected automatically at compile-time. The following 5408** implementations are available in the SQLite core: 5409** 5410** <ul> 5411** <li> SQLITE_MUTEX_OS2 5412** <li> SQLITE_MUTEX_PTHREAD 5413** <li> SQLITE_MUTEX_W32 5414** <li> SQLITE_MUTEX_NOOP 5415** </ul> 5416** 5417** The SQLITE_MUTEX_NOOP implementation is a set of routines 5418** that does no real locking and is appropriate for use in 5419** a single-threaded application. The SQLITE_MUTEX_OS2, 5420** SQLITE_MUTEX_PTHREAD, and SQLITE_MUTEX_W32 implementations 5421** are appropriate for use on os/2, unix, and windows. 5422** 5423** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 5424** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 5425** implementation is included with the library. The 5426** mutex interface routines defined here become external 5427** references in the SQLite library for which implementations 5428** must be provided by the application. This facility allows an 5429** application that links against SQLite to provide its own mutex 5430** implementation without having to modify the SQLite core. 5431** 5432** {F17011} The sqlite3_mutex_alloc() routine allocates a new 5433** mutex and returns a pointer to it. {F17012} If it returns NULL 5434** that means that a mutex could not be allocated. {F17013} SQLite 5435** will unwind its stack and return an error. {F17014} The argument 5436** to sqlite3_mutex_alloc() is one of these integer constants: 5437** 5438** <ul> 5439** <li> SQLITE_MUTEX_FAST 5440** <li> SQLITE_MUTEX_RECURSIVE 5441** <li> SQLITE_MUTEX_STATIC_MASTER 5442** <li> SQLITE_MUTEX_STATIC_MEM 5443** <li> SQLITE_MUTEX_STATIC_MEM2 5444** <li> SQLITE_MUTEX_STATIC_PRNG 5445** <li> SQLITE_MUTEX_STATIC_LRU 5446** <li> SQLITE_MUTEX_STATIC_LRU2 5447** </ul> {END} 5448** 5449** {F17015} The first two constants cause sqlite3_mutex_alloc() to create 5450** a new mutex. The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 5451** is used but not necessarily so when SQLITE_MUTEX_FAST is used. {END} 5452** The mutex implementation does not need to make a distinction 5453** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 5454** not want to. {F17016} But SQLite will only request a recursive mutex in 5455** cases where it really needs one. {END} If a faster non-recursive mutex 5456** implementation is available on the host platform, the mutex subsystem 5457** might return such a mutex in response to SQLITE_MUTEX_FAST. 5458** 5459** {F17017} The other allowed parameters to sqlite3_mutex_alloc() each return 5460** a pointer to a static preexisting mutex. {END} Four static mutexes are 5461** used by the current version of SQLite. Future versions of SQLite 5462** may add additional static mutexes. Static mutexes are for internal 5463** use by SQLite only. Applications that use SQLite mutexes should 5464** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 5465** SQLITE_MUTEX_RECURSIVE. 5466** 5467** {F17018} Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 5468** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 5469** returns a different mutex on every call. {F17034} But for the static 5470** mutex types, the same mutex is returned on every call that has 5471** the same type number. {END} 5472** 5473** {F17019} The sqlite3_mutex_free() routine deallocates a previously 5474** allocated dynamic mutex. {F17020} SQLite is careful to deallocate every 5475** dynamic mutex that it allocates. {U17021} The dynamic mutexes must not be in 5476** use when they are deallocated. {U17022} Attempting to deallocate a static 5477** mutex results in undefined behavior. {F17023} SQLite never deallocates 5478** a static mutex. {END} 5479** 5480** The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 5481** to enter a mutex. {F17024} If another thread is already within the mutex, 5482** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 5483** SQLITE_BUSY. {F17025} The sqlite3_mutex_try() interface returns SQLITE_OK 5484** upon successful entry. {F17026} Mutexes created using 5485** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 5486** {F17027} In such cases the, 5487** mutex must be exited an equal number of times before another thread 5488** can enter. {U17028} If the same thread tries to enter any other 5489** kind of mutex more than once, the behavior is undefined. 5490** {F17029} SQLite will never exhibit 5491** such behavior in its own use of mutexes. {END} 5492** 5493** Some systems (ex: windows95) do not the operation implemented by 5494** sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() will 5495** always return SQLITE_BUSY. {F17030} The SQLite core only ever uses 5496** sqlite3_mutex_try() as an optimization so this is acceptable behavior. {END} 5497** 5498** {F17031} The sqlite3_mutex_leave() routine exits a mutex that was 5499** previously entered by the same thread. {U17032} The behavior 5500** is undefined if the mutex is not currently entered by the 5501** calling thread or is not currently allocated. {F17033} SQLite will 5502** never do either. {END} 5503** 5504** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 5505*/ 5506sqlite3_mutex *sqlite3_mutex_alloc(int); 5507void sqlite3_mutex_free(sqlite3_mutex*); 5508void sqlite3_mutex_enter(sqlite3_mutex*); 5509int sqlite3_mutex_try(sqlite3_mutex*); 5510void sqlite3_mutex_leave(sqlite3_mutex*); 5511 5512/* 5513** CAPI3REF: Mutex Verifcation Routines {F17080} 5514** 5515** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 5516** are intended for use inside assert() statements. {F17081} The SQLite core 5517** never uses these routines except inside an assert() and applications 5518** are advised to follow the lead of the core. {F17082} The core only 5519** provides implementations for these routines when it is compiled 5520** with the SQLITE_DEBUG flag. {U17087} External mutex implementations 5521** are only required to provide these routines if SQLITE_DEBUG is 5522** defined and if NDEBUG is not defined. 5523** 5524** {F17083} These routines should return true if the mutex in their argument 5525** is held or not held, respectively, by the calling thread. {END} 5526** 5527** {X17084} The implementation is not required to provided versions of these 5528** routines that actually work. 5529** If the implementation does not provide working 5530** versions of these routines, it should at least provide stubs 5531** that always return true so that one does not get spurious 5532** assertion failures. {END} 5533** 5534** {F17085} If the argument to sqlite3_mutex_held() is a NULL pointer then 5535** the routine should return 1. {END} This seems counter-intuitive since 5536** clearly the mutex cannot be held if it does not exist. But the 5537** the reason the mutex does not exist is because the build is not 5538** using mutexes. And we do not want the assert() containing the 5539** call to sqlite3_mutex_held() to fail, so a non-zero return is 5540** the appropriate thing to do. {F17086} The sqlite3_mutex_notheld() 5541** interface should also return 1 when given a NULL pointer. 5542*/ 5543int sqlite3_mutex_held(sqlite3_mutex*); 5544int sqlite3_mutex_notheld(sqlite3_mutex*); 5545 5546/* 5547** CAPI3REF: Mutex Types {F17001} 5548** 5549** {F17002} The [sqlite3_mutex_alloc()] interface takes a single argument 5550** which is one of these integer constants. {END} 5551*/ 5552#define SQLITE_MUTEX_FAST 0 5553#define SQLITE_MUTEX_RECURSIVE 1 5554#define SQLITE_MUTEX_STATIC_MASTER 2 5555#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 5556#define SQLITE_MUTEX_STATIC_MEM2 4 /* sqlite3_release_memory() */ 5557#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ 5558#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 5559#define SQLITE_MUTEX_STATIC_LRU2 7 /* lru page list */ 5560 5561/* 5562** CAPI3REF: Low-Level Control Of Database Files {F11300} 5563** 5564** {F11301} The [sqlite3_file_control()] interface makes a direct call to the 5565** xFileControl method for the [sqlite3_io_methods] object associated 5566** with a particular database identified by the second argument. {F11302} The 5567** name of the database is the name assigned to the database by the 5568** <a href="lang_attach.html">ATTACH</a> SQL command that opened the 5569** database. {F11303} To control the main database file, use the name "main" 5570** or a NULL pointer. {F11304} The third and fourth parameters to this routine 5571** are passed directly through to the second and third parameters of 5572** the xFileControl method. {F11305} The return value of the xFileControl 5573** method becomes the return value of this routine. 5574** 5575** {F11306} If the second parameter (zDbName) does not match the name of any 5576** open database file, then SQLITE_ERROR is returned. {F11307} This error 5577** code is not remembered and will not be recalled by [sqlite3_errcode()] 5578** or [sqlite3_errmsg()]. {U11308} The underlying xFileControl method might 5579** also return SQLITE_ERROR. {U11309} There is no way to distinguish between 5580** an incorrect zDbName and an SQLITE_ERROR return from the underlying 5581** xFileControl method. {END} 5582** 5583** See also: [SQLITE_FCNTL_LOCKSTATE] 5584*/ 5585int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 5586 5587/* 5588** CAPI3REF: Testing Interface {F11400} 5589** 5590** The sqlite3_test_control() interface is used to read out internal 5591** state of SQLite and to inject faults into SQLite for testing 5592** purposes. The first parameter a operation code that determines 5593** the number, meaning, and operation of all subsequent parameters. 5594** 5595** This interface is not for use by applications. It exists solely 5596** for verifying the correct operation of the SQLite library. Depending 5597** on how the SQLite library is compiled, this interface might not exist. 5598** 5599** The details of the operation codes, their meanings, the parameters 5600** they take, and what they do are all subject to change without notice. 5601** Unlike most of the SQLite API, this function is not guaranteed to 5602** operate consistently from one release to the next. 5603*/ 5604int sqlite3_test_control(int op, ...); 5605 5606/* 5607** CAPI3REF: Testing Interface Operation Codes {F11410} 5608** 5609** These constants are the valid operation code parameters used 5610** as the first argument to [sqlite3_test_control()]. 5611** 5612** These parameters and their meansing are subject to change 5613** without notice. These values are for testing purposes only. 5614** Applications should not use any of these parameters or the 5615** [sqlite3_test_control()] interface. 5616*/ 5617#define SQLITE_TESTCTRL_FAULT_CONFIG 1 5618#define SQLITE_TESTCTRL_FAULT_FAILURES 2 5619#define SQLITE_TESTCTRL_FAULT_BENIGN_FAILURES 3 5620#define SQLITE_TESTCTRL_FAULT_PENDING 4 5621#define SQLITE_TESTCTRL_PRNG_SAVE 5 5622#define SQLITE_TESTCTRL_PRNG_RESTORE 6 5623#define SQLITE_TESTCTRL_PRNG_RESET 7 5624#define SQLITE_TESTCTRL_BITVEC_TEST 8 5625 5626// Begin Android add 5627/* 5628** Android additional API. 5629** 5630** This function changes the default behavior of BEGIN to IMMEDIATE if called 5631** with immediate=1. 5632** Calling with immediate=0 will revert to DEFERRED. 5633*/ 5634int sqlite3_set_transaction_default_immediate(sqlite3*, int immediate); 5635// End Android add 5636 5637/* 5638** Undo the hack that converts floating point types to integer for 5639** builds on processors without floating point support. 5640*/ 5641#ifdef SQLITE_OMIT_FLOATING_POINT 5642# undef double 5643#endif 5644 5645#ifdef __cplusplus 5646} /* End of the 'extern "C"' block */ 5647#endif 5648#endif 5649