SQLite

** on how SQLite interfaces are suppose to operate.
**
** The name of this file under configuration management is "sqlite.h.in".
** The makefile makes some minor changes to this file (such as inserting
** the version number) and changes its name to "sqlite3.h" as
** part of the build process.
**
** @(#) $Id: sqlite.h.in,v 1.361 2008/06/27 14:51:53 drh Exp $
*/
#ifndef _SQLITE3_H_
#define _SQLITE3_H_
#include <stdarg.h>     /* Needed for the definition of va_list */

/*
** Make sure we can call this stuff from C++.

** There can only be a single busy handler defined for each
** [database connection].  Setting a new busy handler clears any
** previously set handler.  Note that calling [sqlite3_busy_timeout()]
** will also set or clear the busy handler.
**
** INVARIANTS:
**
** {F12311} The [sqlite3_busy_handler(D,C,A)] function shall replace
**          busy callback in the [database connection] D with a new

**          a new busy handler C and application data pointer A.
**
** {F12312} Newly created [database connections] shall have a busy
**          handler of NULL.
**
** {F12314} When two or more [database connections] share a
**          [sqlite3_enable_shared_cache | common cache],
**          the busy handler for the database connection currently using
**          the cache shall be invoked when the cache encounters a lock.
**
** {F12316} If a busy handler callback returns zero, then the SQLite interface
**          that provoked the locking event shall return [SQLITE_BUSY].
**
** {F12318} SQLite shall invokes the busy handler with two arguments which
**          are a copy of the pointer supplied by the 3rd parameter to
**          [sqlite3_busy_handler()] and a count of the number of prior
**          invocations of the busy handler for the same locking event.
**
** LIMITATIONS:
**
** {A12319} A busy handler must not close the database connection
**          or [prepared statement] that invoked the busy handler.
*/
int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*);

/*
** CAPI3REF: Set A Busy Timeout {F12340}
**

** There can only be a single busy handler for a particular
** [database connection] any any given moment.  If another busy handler
** was defined  (using [sqlite3_busy_handler()]) prior to calling
** this routine, that other busy handler is cleared.
**
** INVARIANTS:
**
** {F12341} The [sqlite3_busy_timeout()] function shall override any prior
**          [sqlite3_busy_timeout()] or [sqlite3_busy_handler()] setting
**          on the same [database connection].
**
** {F12343} If the 2nd parameter to [sqlite3_busy_timeout()] is less than
**          or equal to zero, then the busy handler shall be cleared so that
**          all subsequent locking events immediately return [SQLITE_BUSY].
**
** {F12344} If the 2nd parameter to [sqlite3_busy_timeout()] is a positive
**          number N, then a busy handler shall be set that repeatedly calls
**          the xSleep() method in the [sqlite3_vfs | VFS interface] until
**          either the lock clears or until the cumulative sleep time
**          reported back by xSleep() exceeds N milliseconds.
*/
int sqlite3_busy_timeout(sqlite3*, int ms);

/*
** CAPI3REF: Convenience Routines For Running Queries {F12370}
**
** Definition: A <b>result table</b> is memory data structure created by the

** interface defined here.  As a consequence, errors that occur in the
** wrapper layer outside of the internal [sqlite3_exec()] call are not
** reflected in subsequent calls to [sqlite3_errcode()] or [sqlite3_errmsg()].
**
** INVARIANTS:
**
** {F12371} If a [sqlite3_get_table()] fails a memory allocation, then
**          it shall free the result table under construction, abort the
**          query in process, skip any subsequent queries, set the
**          *pazResult output pointer to NULL and return [SQLITE_NOMEM].
**
** {F12373} If the pnColumn parameter to [sqlite3_get_table()] is not NULL
**          then a successful invocation of [sqlite3_get_table()] shall
**          write the number of columns in the
**          result set of the query into *pnColumn.

**
** {F12374} If the pnRow parameter to [sqlite3_get_table()] is not NULL
**          then a successful invocation of [sqlite3_get_table()] shall
**          writes the number of rows in the
**          result set of the query into *pnRow.
**
** {F12376} A successful invocation of [sqlite3_get_table()] that computes
**          N rows of result with C columns per row shall make *pazResult
**          point to an array of pointers to (N+1)*C strings where the first
**          C strings are column names as obtained from
**          [sqlite3_column_name()] and the rest are column result values
**          obtained from [sqlite3_column_text()].
**
** {F12379} The values in the pazResult array returned by [sqlite3_get_table()]
**          shall remain valid until cleared by [sqlite3_free_table()].
**
** {F12382} When an error occurs during evaluation of [sqlite3_get_table()]
**          the function shall set *pazResult to NULL, write an error message
**          into memory obtained from [sqlite3_malloc()], make
**          **pzErrmsg point to that error message, and return a
**          appropriate [error code].
*/
int sqlite3_get_table(
  sqlite3 *db,          /* An open database */
  const char *zSql,     /* SQL to be evaluated */
  char ***pazResult,    /* Results of the query */
  int *pnRow,           /* Number of result rows written here */
  int *pnColumn,        /* Number of result columns written here */
  char **pzErrmsg       /* Error msg written here */
);
void sqlite3_free_table(char **result);

/*
** CAPI3REF: Formatted String Printing Functions {F17400}
**
** These routines are workalikes of the "printf()" family of functions