SQLite

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle SELECT statements in SQLite.
**
** $Id: select.c,v 1.334 2007/04/12 03:54:39 drh Exp $
*/
#include "sqliteInt.h"


/*
** Delete all the content of a Select structure but do not deallocate
** the select structure itself.

      int addr1 = sqlite3VdbeCurrentAddr(v);
      int addr2;

      assert( nColumn==1 );
      sqlite3VdbeAddOp(v, OP_NotNull, -1, addr1+3);
      sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
      addr2 = sqlite3VdbeAddOp(v, OP_Goto, 0, 0);
      p->affinity = sqlite3CompareAffinity(pEList->a[0].pExpr,(iParm>>16)&0xff);
      if( pOrderBy ){
        /* At first glance you would think we could optimize out the
        ** ORDER BY in this case since the order of entries in the set
        ** does not matter.  But there might be a LIMIT clause, in which
        ** case the order does matter */
        pushOntoSorter(pParse, pOrderBy, p);
      }else{


        sqlite3VdbeOp3(v, OP_MakeRecord, 1, 0, &p->affinity, 1);
        sqlite3VdbeAddOp(v, OP_IdxInsert, (iParm&0x0000FFFF), 0);
      }
      sqlite3VdbeJumpHere(v, addr2);
      break;
    }

    /* If any row exist in the result set, record that fact and abort.

    }
#ifndef SQLITE_OMIT_SUBQUERY
    case SRT_Set: {
      assert( nColumn==1 );
      sqlite3VdbeAddOp(v, OP_NotNull, -1, sqlite3VdbeCurrentAddr(v)+3);
      sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
      sqlite3VdbeAddOp(v, OP_Goto, 0, sqlite3VdbeCurrentAddr(v)+3);
      sqlite3VdbeOp3(v, OP_MakeRecord, 1, 0, &p->affinity, 1);
      sqlite3VdbeAddOp(v, OP_IdxInsert, (iParm&0x0000FFFF), 0);
      break;
    }
    case SRT_Mem: {
      assert( nColumn==1 );
      sqlite3VdbeAddOp(v, OP_MemStore, iParm, 1);
      /* The LIMIT clause will terminate the loop for us */

/*
** 2001 September 15
**
** 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.
**
*************************************************************************
** Internal interface definitions for SQLite.
**
** @(#) $Id: sqliteInt.h,v 1.551 2007/04/12 03:54:39 drh Exp $
*/
#ifndef _SQLITEINT_H_
#define _SQLITEINT_H_

#if defined(SQLITE_TCL) || defined(TCLSH)
# include <tcl.h>
#endif

  ExprList *pEList;      /* The fields of the result */
  u8 op;                 /* One of: TK_UNION TK_ALL TK_INTERSECT TK_EXCEPT */
  u8 isDistinct;         /* True if the DISTINCT keyword is present */
  u8 isResolved;         /* True once sqlite3SelectResolve() has run. */
  u8 isAgg;              /* True if this is an aggregate query */
  u8 usesEphm;           /* True if uses an OpenEphemeral opcode */
  u8 disallowOrderBy;    /* Do not allow an ORDER BY to be attached if TRUE */
  char affinity;         /* MakeRecord with this affinity for SRT_Set */
  SrcList *pSrc;         /* The FROM clause */
  Expr *pWhere;          /* The WHERE clause */
  ExprList *pGroupBy;    /* The GROUP BY clause */
  Expr *pHaving;         /* The HAVING clause */
  ExprList *pOrderBy;    /* The ORDER BY clause */
  Select *pPrior;        /* Prior select in a compound select statement */
  Select *pRightmost;    /* Right-most select in a compound select statement */

#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is testing SELECT statements that are part of
# expressions.
#
# $Id: subselect.test,v 1.14 2007/04/12 03:54:39 drh Exp $

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

# Omit this whole file if the library is build without subquery support.
ifcapable !subquery {
  finish_test

} {4}
do_test subselect-3.10 {
  execsql {
    SELECT x FROM t3 WHERE x IN
       (SELECT x FROM t3 ORDER BY x DESC LIMIT 1 OFFSET 2);
  }
} {4}

# Ticket #2295.
# Make sure type affinities work correctly on subqueries with
# an ORDER BY clause.
#
do_test subselect-4.1 {
  execsql {
    CREATE TABLE t4(a TEXT, b TEXT);
    INSERT INTO t4 VALUES('a','1');
    INSERT INTO t4 VALUES('b','2');
    INSERT INTO t4 VALUES('c','3');
    SELECT a FROM t4 WHERE b IN (SELECT b FROM t4 ORDER BY b);
  }
} {a b c}
do_test subselect-4.2 {
  execsql {
    SELECT a FROM t4 WHERE b IN (SELECT b FROM t4 ORDER BY b LIMIT 1);
  }
} {a}
do_test subselect-4.3 {
  execsql {
    SELECT a FROM t4 WHERE b IN (SELECT b FROM t4 ORDER BY b DESC LIMIT 1);
  }
} {c}

finish_test