SQLite

** This module contains C code that generates VDBE code used to process
** the WHERE clause of SQL statements.  This module is responsible 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 1.310 2008/06/25 02:47:57 drh Exp $
*/
#include "sqliteInt.h"

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

    if( pExpr->iColumn!=iColumn || sqlite3StrICmp(pColl->zName, zColl) ){
      /* Term j of the ORDER BY clause does not match column i of the index */
      if( i<nEqCol ){
        /* If an index column that is constrained by == fails to match an
        ** ORDER BY term, that is OK.  Just ignore that column of the index
        */
        continue;
      }else if( i==pIdx->nColumn ){
        /* Index column i is the rowid.  All other terms match. */
        break;
      }else{
        /* If an index column fails to match and is not constrained by ==
        ** then the index cannot satisfy the ORDER BY constraint.
        */
        return 0;
      }
    }

#
#***********************************************************************
# This file implements regression tests for SQLite library.
#
# This file implements tests for miscellanous features that were
# left out of other test files.
#
# $Id: misc3.test,v 1.19 2008/06/25 02:47:57 drh Exp $

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

ifcapable {integrityck} {
  # Ticket #529.  Make sure an ABORT does not damage the in-memory cache
  # that will be used by subsequent statements in the same transaction.

      CREATE UNIQUE INDEX ex1i1 ON ex1(a);
      EXPLAIN REINDEX;
    }]
    regexp { IsUnique \d+ \d+ \d+ \d+ } $x
  } {1}
  do_test misc3-6.11 {
    set x [execsql {
      EXPLAIN SELECT a+123456789012, b*4.5678, c FROM ex1 ORDER BY +a, b DESC
    }]
    set y [regexp { 123456789012 } $x]
    lappend y [regexp { 4.5678 } $x]
    lappend y [regexp { hello } $x]
    lappend y [regexp {,-BINARY} $x]
  } {1 1 1 1}

# The focus of this file is testing the compound-SELECT merge
# optimization.  Or, in other words, making sure that all
# possible combinations of UNION, UNION ALL, EXCEPT, and
# INTERSECT work together with an ORDER BY clause (with or w/o
# explicit sort order and explicit collating secquites) and
# with and without optional LIMIT and OFFSET clauses.
#
# $Id: selectA.test,v 1.2 2008/06/25 02:47:57 drh Exp $

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

do_test selectA-1.0 {
  execsql {
    CREATE TABLE t1(a,b,c COLLATE NOCASE);