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 1.264 2007/10/01 13:50:32 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++.

** The sqlite3_errcode() interface returns the numeric
** [SQLITE_OK | result code] or [SQLITE_IOERR_READ | extended result code]
** for the most recent failed sqlite3_* API call associated
** with [sqlite3] handle 'db'.  If a prior API call failed but the
** most recent API call succeeded, the return value from sqlite3_errcode()
** is undefined. 
**
** The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
** text that describes the error, as either UTF8 or UTF16 respectively.
** Memory to hold the error message string is managed internally.  The 
** string may be overwritten or deallocated by subsequent calls to SQLite
** interface functions.
**
** Calls to many sqlite3_* functions set the error code and string returned
** by [sqlite3_errcode()], [sqlite3_errmsg()], and [sqlite3_errmsg16()]

  const char *zDbName,        /* Database name or NULL */
  const char *zTableName,     /* Table name */
  const char *zColumnName,    /* Column name */
  char const **pzDataType,    /* OUTPUT: Declared data type */
  char const **pzCollSeq,     /* OUTPUT: Collation sequence name */
  int *pNotNull,              /* OUTPUT: True if NOT NULL constraint exists */
  int *pPrimaryKey,           /* OUTPUT: True if column part of PK */
  int *pAutoinc               /* OUTPUT: True if column is auto-increment */
);

/*
** CAPI3REF: Load An Extension
**
** Attempt to load an SQLite extension library contained in the file
** zFile.  The entry point is zProc.  zProc may be 0 in which case the

** Where OP is =, <, <=, >, or >=.  The particular operator is stored
** in aConstraint[].op.  The index of the column is stored in 
** aConstraint[].iColumn.  aConstraint[].usable is TRUE if the
** expr on the right-hand side can be evaluated (and thus the constraint
** is usable) and false if it cannot.
**
** The optimizer automatically inverts terms of the form "expr OP column"
** and makes other simplifications to the WHERE clause in an attempt to
** get as many WHERE clause terms into the form shown above as possible.
** The aConstraint[] array only reports WHERE clause terms in the correct
** form that refer to the particular virtual table being queried.
**
** Information about the ORDER BY clause is stored in aOrderBy[].
** Each term of aOrderBy records a column of the ORDER BY clause.
**

  void *,                    /* Client data for xCreate/xConnect */
  void(*xDestroy)(void*)     /* Module destructor function */
);

/*
** Every module implementation uses a subclass of the following structure
** to describe a particular instance of the module.  Each subclass will
** be tailored to the specific needs of the module implementation.   The
** purpose of this superclass is to define certain fields that are common
** to all module implementations.
**
** Virtual tables methods can set an error message by assigning a
** string obtained from sqlite3_mprintf() to zErrMsg.  The method should
** take care that any prior string is freed by a call to sqlite3_free()
** prior to assigning a new string to zErrMsg.  After the error message

/*
** The interface to the virtual-table mechanism defined above (back up
** to a comment remarkably similar to this one) is currently considered
** to be experimental.  The interface might change in incompatible ways.
** If this is a problem for you, do not use the interface at this time.
**
** When the virtual-table mechanism stabilizes, we will declare the
** interface fixed, support it indefinitely, and remove this comment.
**
****** EXPERIMENTAL - subject to change without notice **************
*/

/*
** CAPI3REF: A Handle To An Open BLOB