SQLite

**   drh@hwaci.com
**   http://www.hwaci.com/drh/
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle SELECT statements.
**
** $Id: select.c,v 1.18 2000/06/08 00:28:52 drh Exp $
*/
#include "sqliteInt.h"

/*
** Allocate a new Select structure and return a pointer to that
** structure.
*/

      /* Convert the data in the temporary table into whatever form
      ** it is that we currently need.
      */      
      if( eDest!=priorOp ){
        int iCont, iBreak;
        assert( p->pEList );
        generateColumnNames(pParse, 0, p->pEList);
        if( p->pOrderBy ){
          sqliteVdbeAddOp(v, OP_SortOpen, 0, 0, 0, 0);
        }
        iBreak = sqliteVdbeMakeLabel(v);
        iCont = sqliteVdbeAddOp(v, OP_Next, unionTab, iBreak, 0, 0);
        rc = selectInnerLoop(pParse, 0, unionTab, p->pEList->nExpr,
                             p->pOrderBy, -1, eDest, iParm, 
                             iCont, iBreak);
        if( rc ) return 1;
        sqliteVdbeAddOp(v, OP_Goto, 0, iCont, 0, 0);

      if( rc ) return rc;

      /* Generate code to take the intersection of the two temporary
      ** tables.
      */
      assert( p->pEList );
      generateColumnNames(pParse, 0, p->pEList);
      if( p->pOrderBy ){
        sqliteVdbeAddOp(v, OP_SortOpen, 0, 0, 0, 0);
      }
      iBreak = sqliteVdbeMakeLabel(v);
      iCont = sqliteVdbeAddOp(v, OP_Next, tab1, iBreak, 0, 0);
      sqliteVdbeAddOp(v, OP_Key, tab1, 0, 0, 0);
      sqliteVdbeAddOp(v, OP_NotFound, tab2, iCont, 0, 0);
      rc = selectInnerLoop(pParse, 0, tab1, p->pEList->nExpr,
                             p->pOrderBy, -1, eDest, iParm, 
                             iCont, iBreak);

# Copyright (c) 1999, 2000 D. Richard Hipp
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public
# License as published by the Free Software Foundation; either
# version 2 of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# General Public License for more details.
# 
# You should have received a copy of the GNU General Public
# License along with this library; if not, write to the
# Free Software Foundation, Inc., 59 Temple Place - Suite 330,
# Boston, MA  02111-1307, USA.
#
# Author contact information:
#   drh@hwaci.com
#   http://www.hwaci.com/drh/
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is testing UNION, INTERSECT and EXCEPT operators
# in SELECT statements.
#
# $Id: select4.test,v 1.1 2000/06/08 00:28:52 drh Exp $

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

# Build some test data
#
do_test select4-1.0 {
  set fd [open data1.txt w]
  for {set i 1} {$i<32} {incr i} {
    for {set j 0} {pow(2,$j)<$i} {incr j} {}
    puts $fd "$i\t$j"
  }
  close $fd
  execsql {
    CREATE TABLE t1(n int, log int);
    COPY t1 FROM 'data1.txt'
  }
  file delete data1.txt
  execsql {SELECT DISTINCT log FROM t1 ORDER BY log}
} {0 1 2 3 4 5}

# Union All operator
#
do_test select4-1.1a {
  lsort [execsql {SELECT DISTINCT log FROM t1}]
} {0 1 2 3 4 5}
do_test select4-1.1b {
  lsort [execsql {SELECT n FROM t1 WHERE log=3}]
} {5 6 7 8}
do_test select4-1.1c {
  execsql {
    SELECT DISTINCT log FROM t1
    UNION ALL
    SELECT n FROM t1 WHERE log=3
    ORDER BY log;
  }
} {0 1 2 3 4 5 5 6 7 8}
do_test select4-1.2 {
  execsql {
    SELECT log FROM t1 WHERE n IN 
      (SELECT DISTINCT log FROM t1 UNION ALL
       SELECT n FROM t1 WHERE log=3)
    ORDER BY log;
  }
} {0 1 2 2 3 3 3 3}

# Union operator
#
do_test select4-2.1 {
  execsql {
    SELECT DISTINCT log FROM t1
    UNION
    SELECT n FROM t1 WHERE log=3
    ORDER BY log;
  }
} {0 1 2 3 4 5 6 7 8}
do_test select4-2.2 {
  execsql {
    SELECT log FROM t1 WHERE n IN 
      (SELECT DISTINCT log FROM t1 UNION
       SELECT n FROM t1 WHERE log=3)
    ORDER BY log;
  }
} {0 1 2 2 3 3 3 3}

# Except operator
#
do_test select4-3.1 {
  execsql {
    SELECT DISTINCT log FROM t1
    EXCEPT
    SELECT n FROM t1 WHERE log=3
    ORDER BY log;
  }
} {0 1 2 3 4}
do_test select4-3.2 {
  execsql {
    SELECT log FROM t1 WHERE n IN 
      (SELECT DISTINCT log FROM t1 EXCEPT
       SELECT n FROM t1 WHERE log=3)
    ORDER BY log;
  }
} {0 1 2 2}

# Intersect operator
#
do_test select4-4.1 {
  execsql {
    SELECT DISTINCT log FROM t1
    INTERSECT
    SELECT n FROM t1 WHERE log=3
    ORDER BY log;
  }
} {5}
do_test select4-4.2 {
  execsql {
    SELECT log FROM t1 WHERE n IN 
      (SELECT DISTINCT log FROM t1 INTERSECT
       SELECT n FROM t1 WHERE log=3)
    ORDER BY log;
  }
} {3}

finish_test