sqlite3.h

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**
** The SQLITE_OK result code will never be extended.  It will always
** be exactly zero.
*/
#define SQLITE_IOERR_READ          (SQLITE_IOERR | (1<<8))
#define SQLITE_IOERR_SHORT_READ    (SQLITE_IOERR | (2<<8))
#define SQLITE_IOERR_WRITE         (SQLITE_IOERR | (3<<8))
#define SQLITE_IOERR_FSYNC         (SQLITE_IOERR | (4<<8))
#define SQLITE_IOERR_DIR_FSYNC     (SQLITE_IOERR | (5<<8))
#define SQLITE_IOERR_TRUNCATE      (SQLITE_IOERR | (6<<8))
#define SQLITE_IOERR_FSTAT         (SQLITE_IOERR | (7<<8))
#define SQLITE_IOERR_UNLOCK        (SQLITE_IOERR | (8<<8))
#define SQLITE_IOERR_RDLOCK        (SQLITE_IOERR | (9<<8))
#define SQLITE_IOERR_DELETE        (SQLITE_IOERR | (10<<8))
#define SQLITE_IOERR_BLOCKED       (SQLITE_IOERR | (11<<8))

/*
** CAPI3REF: Enable Or Disable Extended Result Codes
**
** This routine enables or disables the
** [SQLITE_IOERR_READ | extended result codes] feature.
** By default, SQLite API routines return one of only 26 integer
** [SQLITE_OK | result codes].  When extended result codes
** are enabled by this routine, the repetoire of result codes can be
** much larger and can (hopefully) provide more detailed information
** about the cause of an error.
**
** The second argument is a boolean value that turns extended result
** codes on and off.  Extended result codes are off by default for
** backwards compatibility with older versions of SQLite.
*/
int sqlite3_extended_result_codes(sqlite3*, int onoff);

/*
** CAPI3REF: Last Insert Rowid
**
** Each entry in an SQLite table has a unique 64-bit signed integer key
** called the "rowid". The rowid is always available as an undeclared
** column named ROWID, OID, or _ROWID_.  If the table has a column of
** type INTEGER PRIMARY KEY then that column is another an alias for the
** rowid.
**
** This routine returns the rowid of the most recent INSERT into
** the database from the database connection given in the first 
** argument.  If no inserts have ever occurred on this database
** connection, zero is returned.
**
** If an INSERT occurs within a trigger, then the rowid of the
** inserted row is returned by this routine as long as the trigger
** is running.  But once the trigger terminates, the value returned
** by this routine reverts to the last value inserted before the
** trigger fired.
*/
sqlite_int64 sqlite3_last_insert_rowid(sqlite3*);

/*
** CAPI3REF: Count The Number Of Rows Modified
**
** This function returns the number of database rows that were changed
** (or inserted or deleted) by the most recent SQL statement.  Only
** changes that are directly specified by the INSERT, UPDATE, or
** DELETE statement are counted.  Auxiliary changes caused by
** triggers are not counted.  Use the [sqlite3_total_changes()] function
** to find the total number of changes including changes caused by triggers.
**
** Within the body of a trigger, the sqlite3_changes() interface can be
** called to find the number of
** changes in the most recently completed INSERT, UPDATE, or DELETE
** statement within the body of the trigger.
**
** All changes are counted, even if they were later undone by a
** ROLLBACK or ABORT.  Except, changes associated with creating and
** dropping tables are not counted.
**
** If a callback invokes [sqlite3_exec()] or [sqlite3_step()] recursively,
** then the changes in the inner, recursive call are counted together
** with the changes in the outer call.
**
** SQLite implements the command "DELETE FROM table" without a WHERE clause
** by dropping and recreating the table.  (This is much faster than going
** through and deleting individual elements form the table.)  Because of
** this optimization, the change count for "DELETE FROM table" will be
** zero regardless of the number of elements that were originally in the
** table. To get an accurate count of the number of rows deleted, use
** "DELETE FROM table WHERE 1" instead.
*/
int sqlite3_changes(sqlite3*);

/*
** CAPI3REF: Total Number Of Rows Modified
***
** This function returns the number of database rows that have been
** modified by INSERT, UPDATE or DELETE statements since the database handle
** was opened. This includes UPDATE, INSERT and DELETE statements executed
** as part of trigger programs. All changes are counted as soon as the
** statement that makes them is completed (when the statement handle is
** passed to [sqlite3_reset()] or [sqlite_finalise()]).
**
** See also the [sqlite3_change()] interface.
**
** SQLite implements the command "DELETE FROM table" without a WHERE clause
** by dropping and recreating the table.  (This is much faster than going
** through and deleting individual elements form the table.)  Because of
** this optimization, the change count for "DELETE FROM table" will be
** zero regardless of the number of elements that were originally in the
** table. To get an accurate count of the number of rows deleted, use
** "DELETE FROM table WHERE 1" instead.
*/
int sqlite3_total_changes(sqlite3*);

/*
** CAPI3REF: Interrupt A Long-Running Query
**
** This function causes any pending database operation to abort and
** return at its earliest opportunity.  This routine is typically
** called in response to a user action such as pressing "Cancel"
** or Ctrl-C where the user wants a long query operation to halt
** immediately.
**
** It is safe to call this routine from a thread different from the
** thread that is currently running the database operation.
**
** The SQL operation that is interrupted will return [SQLITE_INTERRUPT].
** If an interrupted operation was an update that is inside an
** explicit transaction, then the entire transaction will be rolled
** back automatically.
*/
void sqlite3_interrupt(sqlite3*);

/*
** CAPI3REF: Determine If An SQL Statement Is Complete
**
** These functions return true if the given input string comprises
** one or more complete SQL statements. For the sqlite3_complete() call,
** the parameter must be a nul-terminated UTF-8 string. For
** sqlite3_complete16(), a nul-terminated machine byte order UTF-16 string
** is required.
**
** These routines are useful for command-line input to determine if the
** currently entered text forms one or more complete SQL statements or
** if additional input is needed before sending the statements into
** SQLite for parsing. The algorithm is simple.  If the 
** last token other than spaces and comments is a semicolon, then return 
** true.  Actually, the algorithm is a little more complicated than that
** in order to deal with triggers, but the basic idea is the same:  the
** statement is not complete unless it ends in a semicolon.
*/
int sqlite3_complete(const char *sql);
int sqlite3_complete16(const void *sql);

/*
** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
**
** This routine identifies a callback function that might be invoked
** whenever an attempt is made to open a database table 
** that another thread or process has locked.
** If the busy callback is NULL, then [SQLITE_BUSY]
** (or sometimes [SQLITE_IOERR_BLOCKED])
** is returned immediately upon encountering the lock.
** If the busy callback is not NULL, then the
** callback will be invoked with two arguments.  The
** first argument to the handler is a copy of the void* pointer which
** is the third argument to this routine.  The second argument to
** the handler is the number of times that the busy handler has
** been invoked for this locking event. If the
** busy callback returns 0, then no additional attempts are made to
** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned.
** If the callback returns non-zero, then another attempt is made to open the
** database for reading and the cycle repeats.
**
** The presence of a busy handler does not guarantee that
** it will be invoked when there is lock contention.
** If SQLite determines that invoking the busy handler could result in
** a deadlock, it will return [SQLITE_BUSY] instead.
** Consider a scenario where one process is holding a read lock that
** it is trying to promote to a reserved lock and
** a second process is holding a reserved lock that it is trying
** to promote to an exclusive lock.  The first process cannot proceed
** because it is blocked by the second and the second process cannot
** proceed because it is blocked by the first.  If both processes
** invoke the busy handlers, neither will make any progress.  Therefore,
** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
** will induce the first process to release its read lock and allow
** the second process to proceed.
**
** The default busy callback is NULL.
**
** The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED] when
** SQLite is in the middle of a large transaction where all the
** changes will not fit into the in-memory cache.  SQLite will
** already hold a RESERVED lock on the database file, but it needs
** to promote this lock to EXCLUSIVE so that it can spill cache
** pages into the database file without harm to concurrent
** readers.  If it is unable to promote the lock, then the in-memory
** cache will be left in an inconsistent state and so the error
** code is promoted from the relatively benign [SQLITE_BUSY] to
** the more severe [SQLITE_IOERR_BLOCKED].  This error code promotion
** forces an automatic rollback of the changes. See the
** <a href="http://www.sqlite.org/cvstrac/wiki?p=CorruptionFollowingBusyError">
** CorruptionFollowingBusyError</a> wiki page for a discussion of why
** this is important.
**	
** Sqlite is re-entrant, so the busy handler may start a new query. 
** (It is not clear why anyone would every want to do this, but it
** is allowed, in theory.)  But the busy handler may not close the
** database.  Closing the database from a busy handler will delete 
** data structures out from under the executing query and will 
** probably result in a segmentation fault or other runtime error.
**
** There can only be a single busy handler defined for each database
** connection.  Setting a new busy handler clears any previous one.
** Note that calling [sqlite3_busy_timeout()] will also set or clear
** the busy handler.
*/
int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*);

/*
** CAPI3REF: Set A Busy Timeout
**
** This routine sets a busy handler that sleeps for a while when a
** table is locked.  The handler will sleep multiple times until 
** at least "ms" milliseconds of sleeping have been done.  After
** "ms" milliseconds of sleeping, the handler returns 0 which
** causes [sqlite3_step()] to return [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED].
**
** Calling this routine with an argument less than or equal to zero
** turns off all busy handlers.
**
** There can only be a single busy handler for a particular database
** connection.  If another busy handler was defined  
** (using [sqlite3_busy_handler()]) prior to calling
** this routine, that other busy handler is cleared.
*/
int sqlite3_busy_timeout(sqlite3*, int ms);

/*
** CAPI3REF: Convenience Routines For Running Queries
**
** This next routine is a convenience wrapper around [sqlite3_exec()].
** Instead of invoking a user-supplied callback for each row of the
** result, this routine remembers each row of the result in memory
** obtained from [sqlite3_malloc()], then returns all of the result after the
** query has finished. 
**
** As an example, suppose the query result where this table:
**
** <pre>
**        Name        | Age
**        -----------------------
**        Alice       | 43
**        Bob         | 28
**        Cindy       | 21
** </pre>
**
** If the 3rd argument were &azResult then after the function returns
** azResult will contain the following data:
**
** <pre>
**        azResult[0] = "Name";
**        azResult[1] = "Age";
**        azResult[2] = "Alice";
**        azResult[3] = "43";
**        azResult[4] = "Bob";
**        azResult[5] = "28";
**        azResult[6] = "Cindy";
**        azResult[7] = "21";
** </pre>
**
** Notice that there is an extra row of data containing the column
** headers.  But the *nrow return value is still 3.  *ncolumn is
** set to 2.  In general, the number of values inserted into azResult
** will be ((*nrow) + 1)*(*ncolumn).
**
** After the calling function has finished using the result, it should 
** pass the result data pointer to sqlite3_free_table() in order to 
** release the memory that was malloc-ed.  Because of the way the 
** [sqlite3_malloc()] happens, the calling function must not try to call 
** [sqlite3_free()] directly.  Only [sqlite3_free_table()] is able to release 
** the memory properly and safely.
**
** The return value of this routine is the same as from [sqlite3_exec()].
*/
int sqlite3_get_table(
  sqlite3*,              /* An open database */
  const char *sql,       /* SQL to be executed */
  char ***resultp,       /* Result written to a char *[]  that this points to */
  int *nrow,             /* Number of result rows written here */
  int *ncolumn,          /* Number of result columns written here */
  char **errmsg          /* Error msg written here */
);
void sqlite3_free_table(char **result);