SQLite

** inplicit conversion from one type to the other occurs as necessary.
** 
** Most of the code in this file is taken up by the sqliteVdbeExec()
** function which does the work of interpreting a VDBE program.
** But other routines are also provided to help in building up
** a program instruction by instruction.
**
** $Id: vdbe.c,v 1.10 2000/06/02 15:05:33 drh Exp $
*/
#include "sqliteInt.h"

/*
** SQL is translated into a sequence of instructions to be
** executed by a virtual machine.  Each instruction is an instance
** of the following structure.

        int j;
        if( i<0 ) goto not_enough_stack;
        if( NeedStack(p, p->tos+2) ) goto no_mem;
        for(j=i; j<=p->tos; j++){
          if( Stringify(p, j) ) goto no_mem;
        }
        p->zStack[p->tos+1] = 0;
        if( xCallback!=0 ){
          if( xCallback(pArg, pOp->p1, &p->zStack[i], p->azColName)!=0 ){
            rc = SQLITE_ABORT;
          }
        }
        PopStack(p, pOp->p1);
        break;
      }

      /* Opcode: Concat * * *
      **

      ** the SortMakeRec operation with the same P1 value as this
      ** instruction.  Pop this record from the stack and invoke the
      ** callback on it.
      */
      case OP_SortCallback: {
        int i = p->tos;
        if( i<0 ) goto not_enough_stack;
        if( xCallback!=0 ){
          if( xCallback(pArg, pOp->p1, (char**)p->zStack[i], p->azColName) ){
            rc = SQLITE_ABORT;
          }
        }
        PopStack(p, 1);
        break;
      }

      /* Opcode: SortClose P1 * *
      **

#   drh@hwaci.com
#   http://www.hwaci.com/drh/
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is testing the SELECT statement.
#
# $Id: select2.test,v 1.4 2000/06/02 15:05:33 drh Exp $

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

# Create a table with some data
#
execsql {CREATE TABLE tbl1(f1 int, f2 int)}
set f [open ./testdata1.txt w]
for {set i 0} {$i<=30} {incr i} {
  puts $f "[expr {$i%9}]\t[expr {$i%10}]"
}
close $f
execsql {COPY tbl1 FROM './testdata1.txt'}
file delete -force ./testdata1.txt

# Do a second query inside a first.
#
do_test select2-1.1 {
  set sql {SELECT DISTINCT f1 FROM tbl1 ORDER BY f1}
  set r {}
  db eval $sql data {
    set f1 $data(f1)
    lappend r $f1:
    set sql2 "SELECT f2 FROM tbl1 WHERE f1=$f1 ORDER BY f2"
    db eval $sql2 d2 {
      lappend r $d2(f2)
    }
  }
  set r
} {0: 0 7 8 9 1: 0 1 8 9 2: 0 1 2 9 3: 0 1 2 3 4: 2 3 4 5: 3 4 5 6: 4 5 6 7: 5 6 7 8: 6 7 8}


do_test select2-1.2 {
  set sql {SELECT DISTINCT f1 FROM tbl1 WHERE f1>3 AND f1<5}
  set r {}
  db eval $sql data {
    set f1 $data(f1)
    lappend r $f1:
    set sql2 "SELECT f2 FROM tbl1 WHERE f1=$f1 ORDER BY f2"
    db eval $sql2 d2 {
      lappend r $d2(f2)
    }
  }
  set r
} {4: 2 3 4}

# Create a largish table
#
execsql {CREATE TABLE tbl2(f1 int, f2 int, f3 int)}
set f [open ./testdata1.txt w]
for {set i 1} {$i<=30000} {incr i} {
  puts $f "$i\t[expr {$i*2}]\t[expr {$i*3}]"
}
close $f
execsql {COPY tbl2 FROM './testdata1.txt'}
file delete -force ./testdata1.txt

do_test select2-2.1 {
  execsql {SELECT count(*) FROM tbl2}
} {30000}
do_test select2-2.2 {
  execsql {SELECT count(*) FROM tbl2 WHERE f2>1000}
} {29500}

do_test select2-3.1 {
  execsql {SELECT f1 FROM tbl2 WHERE f2==1000}
} {500}

execsql {CREATE INDEX idx1 ON tbl2(f2)}

do_test select2-3.2 {
  execsql {SELECT f1 FROM tbl2 WHERE f2==1000}
} {500}

# Make sure queries run faster with an index than without
#
do_test select2-3.3 {
  set t1 [lindex [time {execsql {SELECT f1 from tbl2 WHERE f2==2000}} 1] 0]
  execsql {DROP INDEX idx1}
  set t2 [lindex [time {execsql {SELECT f1 FROM tbl2 WHERE f2==2000}} 1] 0]
  expr {$t1*25 < $t2}
} {1}

finish_test