SQLite

** This module contains C code that generates VDBE code used to process
** the WHERE clause of SQL statements.  This module is reponsible for
** generating the code that loops through a table looking for applicable
** rows.  Indices are selected and used to speed the search when doing
** so is applicable.  Because this module is responsible for selecting
** indices, you might also think of this module as the "query optimizer".
**
** $Id: where.c,v 1.243 2007/03/30 09:13:14 danielk1977 Exp $
*/
#include "sqliteInt.h"

/*
** The number of bits in a Bitmask.  "BMS" means "BitMask Size".
*/
#define BMS  (sizeof(Bitmask)*8)

  }
  pLeft = pList->a[1].pExpr;
  if( pLeft->op!=TK_COLUMN ){
    return 0;
  }
  pColl = pLeft->pColl;
  if( pColl==0 ){
    /* TODO: Coverage testing doesn't get this case. Is it actually possible
    ** for an expression of type TK_COLUMN to not have an assigned collation 
    ** sequence at this point?
    */
    pColl = db->pDfltColl;
  }
  if( (pColl->type!=SQLITE_COLL_BINARY || noCase) &&
      (pColl->type!=SQLITE_COLL_NOCASE || !noCase) ){
    return 0;
  }
  sqlite3DequoteExpr(pRight);

  /* At this point, the sqlite3_index_info structure that pIdxInfo points
  ** to will have been initialized, either during the current invocation or
  ** during some prior invocation.  Now we just have to customize the
  ** details of pIdxInfo for the current invocation and pass it to
  ** xBestIndex.
  */

  /* The module name must be defined. Also, by this point there must
  ** be a pointer to an sqlite3_vtab structure. Otherwise
  ** sqlite3ViewGetColumnNames() would have picked up the error. 
  */
  assert( pTab->azModuleArg && pTab->azModuleArg[0] );
  assert( pTab->pVtab );
#if 0
  if( pTab->pVtab==0 ){
    sqlite3ErrorMsg(pParse, "undefined module %s for table %s",
        pTab->azModuleArg[0], pTab->zName);
    return 0.0;
  }
#endif

  /* Set the aConstraint[].usable fields and initialize all 
  ** output variables to zero.
  **
  ** aConstraint[].usable is true for constraints where the right-hand
  ** side contains only references to tables to the left of the current
  ** table.  In other words, if the constraint is of the form:

# 2006 September 4
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.
#
# $Id: misc7.test,v 1.4 2007/03/30 09:13:14 danielk1977 Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl

do_test misc7-1 {
  c_misuse_test
} {}

} {1}
db2 close

#--------------------------------------------------------------------
# Test that nothing goes horribly wrong when attaching a database
# after the omit_readlock pragma has been exercised.
#
do_test misc7-7.1 {
  file delete -force test2.db
  file delete -force test2.db-journal
  execsql {
    PRAGMA omit_readlock = 1;
    ATTACH 'test2.db' AS aux;
    CREATE TABLE aux.hello(world);
    SELECT name FROM aux.sqlite_master;
  }
} {hello}
do_test misc7-7.2 {
  execsql {
    DETACH aux;
  }
} {}

# Test malloc failure whilst installing a foriegn key.
#
ifcapable utf16 {
  do_test misc7-8 {
    encoding convertfrom unicode [sqlite3_errmsg16 0x00000000]
  } {out of memory}
}

do_test misc7-9 {
  execsql {
    SELECT * 
    FROM (SELECT name+1 AS one FROM sqlite_master LIMIT 1 OFFSET 1) 
    WHERE one LIKE 'hello%';
  }
} {}

#--------------------------------------------------------------------
# Improve reported coverage by running some debugging code:
#
ifcapable vtab {
  do_test misc7-10 {
    register_echo_module [sqlite3_connection_pointer db]
    set sqlite_where_trace 1
    execsql {
      CREATE VIRTUAL TABLE t1 USING echo(abc);
      SELECT a FROM t1 WHERE a = 1 ORDER BY b;
    }
  } {1}
}

finish_test