**    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 1.173 2004/05/21 02:14:25 drh Exp $
*/
#include "sqliteInt.h"


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

    /* Send the data to the callback function.
    */
    case SRT_Callback:
    case SRT_Sorter: {
      if( pOrderBy ){
        sqlite3VdbeAddOp(v, OP_SortMakeRec, nColumn, 0);
        pushOntoSorter(pParse, v, pOrderBy);
      }else{
        assert( eDest==SRT_Callback );
        sqlite3VdbeAddOp(v, OP_Callback, nColumn, 0);
      }
      break;
    }
................................................................................
    sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
    sqlite3VdbeAddOp(v, OP_Goto, 0, addr);
  }
  if( p->iLimit>=0 ){
    sqlite3VdbeAddOp(v, OP_MemIncr, p->iLimit, end2);
  }
  switch( eDest ){
    case SRT_Callback: {
      sqlite3VdbeAddOp(v, OP_SortCallback, nColumn, 0);
      break;
    }
    case SRT_Table:
    case SRT_TempTable: {
      sqlite3VdbeAddOp(v, OP_NewRecno, iParm, 0);
      sqlite3VdbeAddOp(v, OP_Pull, 1, 0);
      sqlite3VdbeAddOp(v, OP_PutIntKey, iParm, 0);
      break;
    }
................................................................................
    }
    case SRT_Mem: {
      assert( nColumn==1 );
      sqlite3VdbeAddOp(v, OP_MemStore, iParm, 1);
      sqlite3VdbeAddOp(v, OP_Goto, 0, end1);
      break;
    }

    case SRT_Subroutine: {
      int i;
      sqlite3VdbeAddOp(v, OP_Integer, p->pEList->nExpr, 0);
      sqlite3VdbeAddOp(v, OP_Pull, 1, 0);
      for(i=0; i<nColumn; i++){
        sqlite3VdbeAddOp(v, OP_Column, -1-i, i);
      }



      sqlite3VdbeAddOp(v, OP_Gosub, 0, iParm);

      sqlite3VdbeAddOp(v, OP_Pop, 2, 0);
      break;
    }
    default: {
      /* Do nothing */
      break;
    }

**    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 1.174 2004/05/21 03:01:59 drh Exp $
*/
#include "sqliteInt.h"


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

    /* Send the data to the callback function.
    */
    case SRT_Callback:
    case SRT_Sorter: {
      if( pOrderBy ){
        sqlite3VdbeAddOp(v, OP_MakeRecord, nColumn, 0);
        pushOntoSorter(pParse, v, pOrderBy);
      }else{
        assert( eDest==SRT_Callback );
        sqlite3VdbeAddOp(v, OP_Callback, nColumn, 0);
      }
      break;
    }
................................................................................
    sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
    sqlite3VdbeAddOp(v, OP_Goto, 0, addr);
  }
  if( p->iLimit>=0 ){
    sqlite3VdbeAddOp(v, OP_MemIncr, p->iLimit, end2);
  }
  switch( eDest ){




    case SRT_Table:
    case SRT_TempTable: {
      sqlite3VdbeAddOp(v, OP_NewRecno, iParm, 0);
      sqlite3VdbeAddOp(v, OP_Pull, 1, 0);
      sqlite3VdbeAddOp(v, OP_PutIntKey, iParm, 0);
      break;
    }
................................................................................
    }
    case SRT_Mem: {
      assert( nColumn==1 );
      sqlite3VdbeAddOp(v, OP_MemStore, iParm, 1);
      sqlite3VdbeAddOp(v, OP_Goto, 0, end1);
      break;
    }
    case SRT_Callback:
    case SRT_Subroutine: {
      int i;
      sqlite3VdbeAddOp(v, OP_Integer, p->pEList->nExpr, 0);
      sqlite3VdbeAddOp(v, OP_Pull, 1, 0);
      for(i=0; i<nColumn; i++){
        sqlite3VdbeAddOp(v, OP_Column, -1-i, i);
      }
      if( eDest==SRT_Callback ){
        sqlite3VdbeAddOp(v, OP_Callback, nColumn, 0);
      }else{
        sqlite3VdbeAddOp(v, OP_Gosub, 0, iParm);
      }
      sqlite3VdbeAddOp(v, OP_Pop, 2, 0);
      break;
    }
    default: {
      /* Do nothing */
      break;
    }

**
** Various scripts scan this source file in order to generate HTML
** documentation, headers files, or other derived files.  The formatting
** of the code in this file is, therefore, important.  See other comments
** in this file for details.  If in doubt, do not deviate from existing
** commenting and indentation practices when changing or adding code.
**
** $Id: vdbe.c,v 1.311 2004/05/21 02:14:25 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>
#include "vdbeInt.h"

/*
................................................................................
  assert( pNos->flags & MEM_Dyn );
  pSorter->nData = pNos->n;
  pSorter->pData = pNos->z;
  pTos -= 2;
  break;
}

/* Opcode: SortMakeRec P1 * *
**
** The top P1 elements are the arguments to a callback.  Form these
** elements into a single data entry that can be stored on a sorter
** using SortPut and later fed to a callback using SortCallback.
*/
case OP_SortMakeRec: {
  char *z;
  char **azArg;
  int nByte;
  int nField;
  int i;
  Mem *pRec;

  nField = pOp->p1;
  pRec = &pTos[1-nField];
  assert( pRec>=p->aStack );
  nByte = 0;
  for(i=0; i<nField; i++, pRec++){
    if( (pRec->flags & MEM_Null)==0 ){
      Stringify(pRec);
      nByte += pRec->n;
    }
  }
  nByte += sizeof(char*)*(nField+1);
  azArg = sqliteMallocRaw( nByte );
  if( azArg==0 ) goto no_mem;
  z = (char*)&azArg[nField+1];
  for(pRec=&pTos[1-nField], i=0; i<nField; i++, pRec++){
    if( pRec->flags & MEM_Null ){
      azArg[i] = 0;
    }else{
      azArg[i] = z;
      memcpy(z, pRec->z, pRec->n);
      z += pRec->n;
    }
  }
  popStack(&pTos, nField);
  pTos++;
  pTos->n = nByte;
  pTos->z = (char*)azArg;
  pTos->flags = MEM_Str | MEM_Dyn;
  break;
}

/* Opcode: Sort * * P3
**
** Sort all elements on the sorter.  The algorithm is a
** mergesort.  The P3 argument is a pointer to a KeyInfo structure
** that describes the keys to be sorted.
*/
case OP_Sort: {
................................................................................
    sqliteFree(pSorter);
  }else{
    pc = pOp->p2 - 1;
  }
  break;
}

/* Opcode: SortCallback P1 * *
**
** The top of the stack contains a callback record built using
** 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: {
  assert( pTos>=p->aStack );
  assert( pTos->flags & MEM_Str );
  p->nCallback++;
  p->pc = pc+1;
  p->azResColumn = (char**)pTos->z;
  assert( p->nResColumn==pOp->p1 );
  p->popStack = 1;
  p->pTos = pTos;
  return SQLITE_ROW;
}

/* Opcode: SortReset * * *
**
** Remove any elements that remain on the sorter.
*/
case OP_SortReset: {
  sqlite3VdbeSorterReset(p);
  break;

**
** Various scripts scan this source file in order to generate HTML
** documentation, headers files, or other derived files.  The formatting
** of the code in this file is, therefore, important.  See other comments
** in this file for details.  If in doubt, do not deviate from existing
** commenting and indentation practices when changing or adding code.
**
** $Id: vdbe.c,v 1.312 2004/05/21 03:01:59 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>
#include "vdbeInt.h"

/*
................................................................................
  assert( pNos->flags & MEM_Dyn );
  pSorter->nData = pNos->n;
  pSorter->pData = pNos->z;
  pTos -= 2;
  break;
}














































/* Opcode: Sort * * P3
**
** Sort all elements on the sorter.  The algorithm is a
** mergesort.  The P3 argument is a pointer to a KeyInfo structure
** that describes the keys to be sorted.
*/
case OP_Sort: {
................................................................................
    sqliteFree(pSorter);
  }else{
    pc = pOp->p2 - 1;
  }
  break;
}




















/* Opcode: SortReset * * *
**
** Remove any elements that remain on the sorter.
*/
case OP_SortReset: {
  sqlite3VdbeSorterReset(p);
  break;

#    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.  The
# focus of this file is testing the use of indices in WHERE clases.
#
# $Id: where.test,v 1.20 2004/05/21 02:14:25 drh Exp $

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

# Build some test data
#
do_test where-1.0 {
................................................................................
# for the SQL and appends a "nosort" to the result if the program contains the
# SortCallback opcode.  If the program does not contain the SortCallback
# opcode it appends "sort"
#
proc cksort {sql} {
  set data [execsql $sql]
  set prog [execsql "EXPLAIN $sql"]
  if {[regexp SortCallback $prog]} {set x sort} {set x nosort}
  lappend data $x
  return $data
}
# Check out the logic that attempts to implement the ORDER BY clause
# using an index rather than by sorting.
#
do_test where-6.1 {

#    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.  The
# focus of this file is testing the use of indices in WHERE clases.
#
# $Id: where.test,v 1.21 2004/05/21 03:01:59 drh Exp $

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

# Build some test data
#
do_test where-1.0 {
................................................................................
# for the SQL and appends a "nosort" to the result if the program contains the
# SortCallback opcode.  If the program does not contain the SortCallback
# opcode it appends "sort"
#
proc cksort {sql} {
  set data [execsql $sql]
  set prog [execsql "EXPLAIN $sql"]
  if {[regexp Sort $prog]} {set x sort} {set x nosort}
  lappend data $x
  return $data
}
# Check out the logic that attempts to implement the ORDER BY clause
# using an index rather than by sorting.
#
do_test where-6.1 {