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Overview
Comment:Fix for ticket #147: Honor the ORDER BY and LIMIT clauses in a SELECT even if the destination of that SELECT is a subroutine call. (CVS 747)
Downloads: Tarball | ZIP archive | SQL archive
Timelines: family | ancestors | descendants | both | trunk
Files: files | file ages | folders
SHA1:23fe36c7e88282f6d1b7547ab892ea88f0e65262
User & Date: drh 2002-09-08 17:23:42
Context
2002-09-12
14:08
Update the SQL language documentation to talk about SELECT DISTINCT. (CVS 748) check-in: ef711675 user: drh tags: trunk
2002-09-08
17:23
Fix for ticket #147: Honor the ORDER BY and LIMIT clauses in a SELECT even if the destination of that SELECT is a subroutine call. (CVS 747) check-in: 23fe36c7 user: drh tags: trunk
00:04
Modify the build process so that the VDBE opcode numbers and the table that contains the opcode names are both automatically generated. This makes it much easier to create new VDBE opcodes. (CVS 1727) check-in: c4f0bb02 user: drh tags: trunk
Changes
Hide Diffs Unified Diffs Ignore Whitespace Patch

Changes to main.mk.

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# This target creates a directory named "tsrc" and fills it with
# copies of all of the C source code and header files needed to
# build on the target system.  Some of the C source code and header
# files are automatically generated.  This target takes care of
# all that automatic generation.
#
target_source:	$(SRC) $(HDR) 
	rm -rf tsrc
	mkdir tsrc
	cp $(SRC) $(HDR) tsrc
	rm tsrc/sqlite.h.in tsrc/parse.y
	cp parse.c tsrc

# Rules to build the LEMON compiler generator
#
lemon:	$(TOP)/tool/lemon.c $(TOP)/tool/lempar.c
	$(BCC) -o lemon $(TOP)/tool/lemon.c
	cp $(TOP)/tool/lempar.c .








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# This target creates a directory named "tsrc" and fills it with
# copies of all of the C source code and header files needed to
# build on the target system.  Some of the C source code and header
# files are automatically generated.  This target takes care of
# all that automatic generation.
#
target_source:	$(SRC) $(HDR) opcodes.c
	rm -rf tsrc
	mkdir tsrc
	cp $(SRC) $(HDR) tsrc
	rm tsrc/sqlite.h.in tsrc/parse.y
	cp parse.c opcodes.c tsrc

# Rules to build the LEMON compiler generator
#
lemon:	$(TOP)/tool/lemon.c $(TOP)/tool/lempar.c
	$(BCC) -o lemon $(TOP)/tool/lemon.c
	cp $(TOP)/tool/lempar.c .

Changes to src/select.c.

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**    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 1.111 2002/08/28 03:00:59 drh Exp $
*/
#include "sqliteInt.h"

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

    /* Invoke a subroutine to handle the results.  The subroutine itself
    ** is responsible for popping the results off of the stack.
    */
    case SRT_Subroutine: {




      sqliteVdbeAddOp(v, OP_Gosub, 0, iParm);

      break;
    }

    /* Discard the results.  This is used for SELECT statements inside
    ** the body of a TRIGGER.  The purpose of such selects is to call
    ** user-defined functions that have side effects.  We do not care
    ** about the actual results of the select.
................................................................................
      break;
    }
    case SRT_Mem: {
      assert( nColumn==1 );
      sqliteVdbeAddOp(v, OP_MemStore, iParm, 1);
      sqliteVdbeAddOp(v, OP_Goto, 0, end);
      break;









    }
    default: {
      /* Do nothing */
      break;
    }
  }
  sqliteVdbeAddOp(v, OP_Goto, 0, addr);







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**    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 1.112 2002/09/08 17:23:43 drh Exp $
*/
#include "sqliteInt.h"

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

    /* Invoke a subroutine to handle the results.  The subroutine itself
    ** is responsible for popping the results off of the stack.
    */
    case SRT_Subroutine: {
      if( pOrderBy ){
        sqliteVdbeAddOp(v, OP_MakeRecord, nColumn, 0);
        pushOntoSorter(pParse, v, pOrderBy);
      }else{
        sqliteVdbeAddOp(v, OP_Gosub, 0, iParm);
      }
      break;
    }

    /* Discard the results.  This is used for SELECT statements inside
    ** the body of a TRIGGER.  The purpose of such selects is to call
    ** user-defined functions that have side effects.  We do not care
    ** about the actual results of the select.
................................................................................
      break;
    }
    case SRT_Mem: {
      assert( nColumn==1 );
      sqliteVdbeAddOp(v, OP_MemStore, iParm, 1);
      sqliteVdbeAddOp(v, OP_Goto, 0, end);
      break;
    }
    case SRT_Subroutine: {
      int i;
      for(i=0; i<nColumn; i++){
        sqliteVdbeAddOp(v, OP_Column, -1-i, i);
      }
      sqliteVdbeAddOp(v, OP_Gosub, 0, iParm);
      sqliteVdbeAddOp(v, OP_Pop, 1, 0);
      break;
    }
    default: {
      /* Do nothing */
      break;
    }
  }
  sqliteVdbeAddOp(v, OP_Goto, 0, addr);

Changes to src/vdbe.c.

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** 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 1.176 2002/09/08 00:04:52 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** The makefile scans this source file and creates the following
** array of string constants which are the names of all VDBE opcodes.
................................................................................
*/
extern char *sqliteOpcodeNames[];

/*
** The following global variable is incremented every time a cursor
** moves, either by the OP_MoveTo or the OP_Next opcode.  The test
** procedures use this information to make sure that indices are
** working correctly.

*/
int sqlite_search_count = 0;

/*
** SQL is translated into a sequence of instructions to be
** executed by a virtual machine.  Each instruction is an instance
** of the following structure.
................................................................................
  Set *aSet;          /* An array of sets */
  int nCallback;      /* Number of callbacks invoked so far */
  int keylistStackDepth;  /* The size of the "keylist" stack */
  Keylist **keylistStack; /* The stack used by opcodes ListPush & ListPop */
};

/*
** When debugging the code generator in a symbolic debugger, on can
** set the sqlite_vdbe_addop_trace to 1 and all opcodes will be printed
** as they are added to the instruction stream.
*/
#ifndef NDEBUG
int sqlite_vdbe_addop_trace = 0;
static void vdbePrintOp(FILE*, int, Op*);
#endif
................................................................................
  }
  p->aLabel[i] = -1;
  return -1-i;
}

/*
** Resolve label "x" to be the address of the next instruction to
** be inserted.

*/
void sqliteVdbeResolveLabel(Vdbe *p, int x){
  int j;
  if( x<0 && (-x)<=p->nLabel && p->aOp ){
    if( p->aLabel[-1-x]==p->nOp ) return;
    assert( p->aLabel[-1-x]<0 );
    p->aLabel[-1-x] = p->nOp;
................................................................................
/*
** The following group or routines are employed by installable functions
** to return their results.
**
** The sqlite_set_result_string() routine can be used to return a string
** value or to return a NULL.  To return a NULL, pass in NULL for zResult.
** A copy is made of the string before this routine returns so it is safe
** to pass in a ephemeral string.
**
** sqlite_set_result_error() works like sqlite_set_result_string() except
** that it signals a fatal error.  The string argument, if any, is the
** error message.  If the argument is NULL a generic substitute error message
** is used.
**
** The sqlite_set_result_int() and sqlite_set_result_double() set the return
** value of the user function to an integer or a double.
**
** These routines are defined here in vdbe.c because they depend on knowing
** the internals of the sqlite_func structure which is only defined in that
** one source file.
*/
char *sqlite_set_result_string(sqlite_func *p, const char *zResult, int n){
  assert( !p->isStep );
  if( p->s.flags & STK_Dyn ){
    sqliteFree(p->z);
  }
  if( zResult==0 ){
................................................................................
}

/*
** Extract the user data from a sqlite_func structure and return a
** pointer to it.
**
** This routine is defined here in vdbe.c because it depends on knowing
** the internals of the sqlite_func structure which is only defined in that
** one source file.
*/
void *sqlite_user_data(sqlite_func *p){
  assert( p && p->pFunc );
  return p->pFunc->pUserData;
}

/*
** Allocate or return the aggregate context for a user function.  A new
** context is allocated on the first call.  Subsequent calls return the
** same context that was returned on prior calls.
**
** This routine is defined here in vdbe.c because it depends on knowing
** the internals of the sqlite_func structure which is only defined in that
** one source file.
*/
void *sqlite_aggregate_context(sqlite_func *p, int nByte){
  assert( p && p->pFunc && p->pFunc->xStep );
  if( p->pAgg==0 ){
    if( nByte<=NBFS ){
      p->pAgg = (void*)p->z;
    }else{
................................................................................
}

/*
** Return the number of times the Step function of a aggregate has been 
** called.
**
** This routine is defined here in vdbe.c because it depends on knowing
** the internals of the sqlite_func structure which is only defined in that
** one source file.
*/
int sqlite_aggregate_count(sqlite_func *p){
  assert( p && p->pFunc && p->pFunc->xStep );
  return p->cnt;
}

/*
................................................................................
  pAgg->apFunc = 0;
  pAgg->pCurrent = 0;
  pAgg->pSearch = 0;
  pAgg->nMem = 0;
}

/*
** Insert a new element and make it the current element.  

**
** Return 0 on success and 1 if memory is exhausted.
*/
static int AggInsert(Agg *p, char *zKey, int nKey){
  AggElem *pElem, *pOld;
  int i;
  pElem = sqliteMalloc( sizeof(AggElem) + nKey +
................................................................................
** What follows is a massive switch statement where each case implements a
** separate instruction in the virtual machine.  If we follow the usual
** indentation conventions, each case should be indented by 6 spaces.  But
** that is a lot of wasted space on the left margin.  So the code within
** the switch statement will break with convention and be flush-left. Another
** big comment (similar to this one) will mark the point in the code where
** we transition back to normal indentation.


















*****************************************************************************/

/* Opcode:  Goto * P2 *
**
** An unconditional jump to address P2.
** The next instruction executed will be 
** the one at index P2 from the beginning of
................................................................................
  break;
}

/* Opcode: Push P1 * *
**
** Overwrite the value of the P1-th element down on the
** stack (P1==0 is the top of the stack) with the value
** of the top of the stack.  The pop the top of the stack.
*/
case OP_Push: {
  int from = p->tos;
  int to = p->tos - pOp->p1;

  VERIFY( if( to<0 ) goto not_enough_stack; )
  if( aStack[to].flags & STK_Dyn ){
................................................................................
** the format of the data.)
** Push onto the stack the value of the P2-th column contained
** in the data.
**
** If the KeyAsData opcode has previously executed on this cursor,
** then the field might be extracted from the key rather than the
** data.






*/
case OP_Column: {
  int amt, offset, end, payloadSize;
  int i = pOp->p1;
  int p2 = pOp->p2;
  int tos = p->tos+1;
  Cursor *pC;

  BtCursor *pCrsr;
  int idxWidth;
  unsigned char aHdr[10];
  int (*xRead)(BtCursor*, int, int, char*);

  VERIFY( if( NeedStack(p, tos+1) ) goto no_mem; )





  if( VERIFY( i>=0 && i<p->nCursor && ) (pC = &p->aCsr[i])->pCursor!=0 ){

    /* Use different access functions depending on whether the information
    ** is coming from the key or the data of the record.
    */

    pCrsr = pC->pCursor;
    if( pC->nullRow ){
      payloadSize = 0;
    }else if( pC->keyAsData ){
      sqliteBtreeKeySize(pCrsr, &payloadSize);
      xRead = sqliteBtreeKey;
    }else{
      sqliteBtreeDataSize(pCrsr, &payloadSize);

      xRead = sqliteBtreeData;

    }

    /* Figure out how many bytes in the column data and where the column
    ** data begins.
    */
    if( payloadSize==0 ){
      aStack[tos].flags = STK_Null;
      p->tos = tos;
      break;
    }else if( payloadSize<256 ){
      idxWidth = 1;
    }else if( payloadSize<65536 ){
      idxWidth = 2;
    }else{
      idxWidth = 3;
    }

    /* Figure out where the requested column is stored and how big it is.
    */
    if( payloadSize < idxWidth*(p2+1) ){
      rc = SQLITE_CORRUPT;
      goto abort_due_to_error;
    }



    (*xRead)(pCrsr, idxWidth*p2, idxWidth*2, (char*)aHdr);



    offset = aHdr[0];
    end = aHdr[idxWidth];
    if( idxWidth>1 ){
      offset |= aHdr[1]<<8;
      end |= aHdr[idxWidth+1]<<8;
      if( idxWidth>2 ){
        offset |= aHdr[2]<<16;
        end |= aHdr[idxWidth+2]<<16;
      }
    }
    amt = end - offset;
    if( amt<0 || offset<0 || end>payloadSize ){
      rc = SQLITE_CORRUPT;
      goto abort_due_to_error;
    }

    /* amt and offset now hold the offset to the start of data and the
    ** amount of data.  Go get the data and put it on the stack.
    */
    if( amt==0 ){
      aStack[tos].flags = STK_Null;
    }else if( amt<=NBFS ){

      (*xRead)(pCrsr, offset, amt, aStack[tos].z);



      aStack[tos].flags = STK_Str;
      zStack[tos] = aStack[tos].z;
      aStack[tos].n = amt;
    }else{
      char *z = sqliteMalloc( amt );
      if( z==0 ) goto no_mem;
      (*xRead)(pCrsr, offset, amt, z);
      aStack[tos].flags = STK_Str | STK_Dyn;
      zStack[tos] = z;
      aStack[tos].n = amt;
    }
    p->tos = tos;



  }


  break;
}

/* Opcode: Extract * * *
*/

/* Opcode: Recno P1 * *
**
** Push onto the stack an integer which is the first 4 bytes of the
** the key to the current entry in a sequential scan of the database
** file P1.  The sequential scan should have been started using the 
** Next opcode.
*/







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** 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.
**
** 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 1.177 2002/09/08 17:23:43 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** The makefile scans this source file and creates the following
** array of string constants which are the names of all VDBE opcodes.
................................................................................
*/
extern char *sqliteOpcodeNames[];

/*
** The following global variable is incremented every time a cursor
** moves, either by the OP_MoveTo or the OP_Next opcode.  The test
** procedures use this information to make sure that indices are
** working correctly.  This variable has no function other than to
** help verify the correct operation of the library.
*/
int sqlite_search_count = 0;

/*
** SQL is translated into a sequence of instructions to be
** executed by a virtual machine.  Each instruction is an instance
** of the following structure.
................................................................................
  Set *aSet;          /* An array of sets */
  int nCallback;      /* Number of callbacks invoked so far */
  int keylistStackDepth;  /* The size of the "keylist" stack */
  Keylist **keylistStack; /* The stack used by opcodes ListPush & ListPop */
};

/*
** When debugging the code generator in a symbolic debugger, one can
** set the sqlite_vdbe_addop_trace to 1 and all opcodes will be printed
** as they are added to the instruction stream.
*/
#ifndef NDEBUG
int sqlite_vdbe_addop_trace = 0;
static void vdbePrintOp(FILE*, int, Op*);
#endif
................................................................................
  }
  p->aLabel[i] = -1;
  return -1-i;
}

/*
** Resolve label "x" to be the address of the next instruction to
** be inserted.  The parameter "x" must have been obtained from
** a prior call to sqliteVdbeMakeLabel().
*/
void sqliteVdbeResolveLabel(Vdbe *p, int x){
  int j;
  if( x<0 && (-x)<=p->nLabel && p->aOp ){
    if( p->aLabel[-1-x]==p->nOp ) return;
    assert( p->aLabel[-1-x]<0 );
    p->aLabel[-1-x] = p->nOp;
................................................................................
/*
** The following group or routines are employed by installable functions
** to return their results.
**
** The sqlite_set_result_string() routine can be used to return a string
** value or to return a NULL.  To return a NULL, pass in NULL for zResult.
** A copy is made of the string before this routine returns so it is safe
** to pass in an ephemeral string.
**
** sqlite_set_result_error() works like sqlite_set_result_string() except
** that it signals a fatal error.  The string argument, if any, is the
** error message.  If the argument is NULL a generic substitute error message
** is used.
**
** The sqlite_set_result_int() and sqlite_set_result_double() set the return
** value of the user function to an integer or a double.
**
** These routines are defined here in vdbe.c because they depend on knowing
** the internals of the sqlite_func structure which is only defined in 
** this source file.
*/
char *sqlite_set_result_string(sqlite_func *p, const char *zResult, int n){
  assert( !p->isStep );
  if( p->s.flags & STK_Dyn ){
    sqliteFree(p->z);
  }
  if( zResult==0 ){
................................................................................
}

/*
** Extract the user data from a sqlite_func structure and return a
** pointer to it.
**
** This routine is defined here in vdbe.c because it depends on knowing
** the internals of the sqlite_func structure which is only defined in 
** this source file.
*/
void *sqlite_user_data(sqlite_func *p){
  assert( p && p->pFunc );
  return p->pFunc->pUserData;
}

/*
** Allocate or return the aggregate context for a user function.  A new
** context is allocated on the first call.  Subsequent calls return the
** same context that was returned on prior calls.
**
** This routine is defined here in vdbe.c because it depends on knowing
** the internals of the sqlite_func structure which is only defined in
** this source file.
*/
void *sqlite_aggregate_context(sqlite_func *p, int nByte){
  assert( p && p->pFunc && p->pFunc->xStep );
  if( p->pAgg==0 ){
    if( nByte<=NBFS ){
      p->pAgg = (void*)p->z;
    }else{
................................................................................
}

/*
** Return the number of times the Step function of a aggregate has been 
** called.
**
** This routine is defined here in vdbe.c because it depends on knowing
** the internals of the sqlite_func structure which is only defined in
** this source file.
*/
int sqlite_aggregate_count(sqlite_func *p){
  assert( p && p->pFunc && p->pFunc->xStep );
  return p->cnt;
}

/*
................................................................................
  pAgg->apFunc = 0;
  pAgg->pCurrent = 0;
  pAgg->pSearch = 0;
  pAgg->nMem = 0;
}

/*
** Insert a new aggregate element and make it the element that
** has focus.
**
** Return 0 on success and 1 if memory is exhausted.
*/
static int AggInsert(Agg *p, char *zKey, int nKey){
  AggElem *pElem, *pOld;
  int i;
  pElem = sqliteMalloc( sizeof(AggElem) + nKey +
................................................................................
** What follows is a massive switch statement where each case implements a
** separate instruction in the virtual machine.  If we follow the usual
** indentation conventions, each case should be indented by 6 spaces.  But
** that is a lot of wasted space on the left margin.  So the code within
** the switch statement will break with convention and be flush-left. Another
** big comment (similar to this one) will mark the point in the code where
** we transition back to normal indentation.
**
** The formatting of each case is important.  The makefile for SQLite
** generates two C files "opcodes.h" and "opcodes.c" by scanning this
** file looking for lines that begin with "case OP_".  The opcodes.h files
** will be filled with #defines that give unique integer values to each
** opcode and the opcodes.c file is filled with an array of strings where
** each string is the symbolic name for the corresponding opcode.
**
** Documentation about VDBE opcodes is generated by scanning this file
** for lines of that contain "Opcode:".  That line and all subsequent
** comment lines are used in the generation of the opcode.html documentation
** file.
**
** SUMMARY:
**
**     Formatting is important to scripts that scan this file.
**     Do not deviate from the formatting style currently in use.
**
*****************************************************************************/

/* Opcode:  Goto * P2 *
**
** An unconditional jump to address P2.
** The next instruction executed will be 
** the one at index P2 from the beginning of
................................................................................
  break;
}

/* Opcode: Push P1 * *
**
** Overwrite the value of the P1-th element down on the
** stack (P1==0 is the top of the stack) with the value
** of the top of the stack.  Then pop the top of the stack.
*/
case OP_Push: {
  int from = p->tos;
  int to = p->tos - pOp->p1;

  VERIFY( if( to<0 ) goto not_enough_stack; )
  if( aStack[to].flags & STK_Dyn ){
................................................................................
** the format of the data.)
** Push onto the stack the value of the P2-th column contained
** in the data.
**
** If the KeyAsData opcode has previously executed on this cursor,
** then the field might be extracted from the key rather than the
** data.
**
** If P1 is negative, then the record is stored on the stack rather
** than in a table.  For P1==-1, the top of the stack is used.
** For P1==-2, the next on the stack is used.  And so forth.  The
** value pushed is always just a pointer into the record which is
** stored further down on the stack.  The column value is not copied.
*/
case OP_Column: {
  int amt, offset, end, payloadSize;
  int i = pOp->p1;
  int p2 = pOp->p2;
  int tos = p->tos+1;
  Cursor *pC;
  char *zRec;
  BtCursor *pCrsr;
  int idxWidth;
  unsigned char aHdr[10];


  VERIFY( if( NeedStack(p, tos+1) ) goto no_mem; )
  if( i<0 ){
    VERIFY( if( tos+i<0 ) goto bad_instruction; )
    VERIFY( if( (aStack[tos+i].flags & STK_Str)==0 ) goto bad_instruction; )
    zRec = zStack[tos+i];
    payloadSize = aStack[tos+i].n;
  }else if( VERIFY( i>=0 && i<p->nCursor && ) (pC = &p->aCsr[i])->pCursor!=0 ){




    zRec = 0;
    pCrsr = pC->pCursor;
    if( pC->nullRow ){
      payloadSize = 0;
    }else if( pC->keyAsData ){
      sqliteBtreeKeySize(pCrsr, &payloadSize);

    }else{
      sqliteBtreeDataSize(pCrsr, &payloadSize);
    }
  }else{
    payloadSize = 0;
  }

  /* Figure out how many bytes in the column data and where the column
  ** data begins.
  */
  if( payloadSize==0 ){
    aStack[tos].flags = STK_Null;
    p->tos = tos;
    break;
  }else if( payloadSize<256 ){
    idxWidth = 1;
  }else if( payloadSize<65536 ){
    idxWidth = 2;
  }else{
    idxWidth = 3;
  }

  /* Figure out where the requested column is stored and how big it is.
  */
  if( payloadSize < idxWidth*(p2+1) ){
    rc = SQLITE_CORRUPT;
    goto abort_due_to_error;
  }
  if( zRec ){
    memcpy(aHdr, &zRec[idxWidth*p2], idxWidth*2);
  }else if( pC->keyAsData ){
    sqliteBtreeKey(pCrsr, idxWidth*p2, idxWidth*2, (char*)aHdr);
  }else{
    sqliteBtreeData(pCrsr, idxWidth*p2, idxWidth*2, (char*)aHdr);
  }
  offset = aHdr[0];
  end = aHdr[idxWidth];
  if( idxWidth>1 ){
    offset |= aHdr[1]<<8;
    end |= aHdr[idxWidth+1]<<8;
    if( idxWidth>2 ){
      offset |= aHdr[2]<<16;
      end |= aHdr[idxWidth+2]<<16;
    }
  }
  amt = end - offset;
  if( amt<0 || offset<0 || end>payloadSize ){
    rc = SQLITE_CORRUPT;
    goto abort_due_to_error;
  }

  /* amt and offset now hold the offset to the start of data and the
  ** amount of data.  Go get the data and put it on the stack.
  */
  if( amt==0 ){
    aStack[tos].flags = STK_Null;
  }else if( zRec ){
    aStack[tos].flags = STK_Str | STK_Static;
    aStack[tos].n = amt;
    zStack[tos] = &zRec[offset];
  }else{
    if( amt<=NBFS ){
      aStack[tos].flags = STK_Str;
      zStack[tos] = aStack[tos].z;
      aStack[tos].n = amt;
    }else{
      char *z = sqliteMalloc( amt );
      if( z==0 ) goto no_mem;

      aStack[tos].flags = STK_Str | STK_Dyn;
      zStack[tos] = z;
      aStack[tos].n = amt;
    }
    if( pC->keyAsData ){
      sqliteBtreeKey(pCrsr, offset, amt, zStack[tos]);
    }else{
      sqliteBtreeData(pCrsr, offset, amt, zStack[tos]);
    }
  }
  p->tos = tos;
  break;
}




/* Opcode: Recno P1 * *
**
** Push onto the stack an integer which is the first 4 bytes of the
** the key to the current entry in a sequential scan of the database
** file P1.  The sequential scan should have been started using the 
** Next opcode.
*/

Changes to test/limit.test.

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#    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 LIMIT ... OFFSET ... clause
#  of SELECT statements.
#
# $Id: limit.test,v 1.5 2002/08/13 23:02:58 drh Exp $

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

# Build some test data
#
set fd [open data1.txt w]
................................................................................
       'abcdefghijklmnopqrstuvwyxz ABCDEFGHIJKLMNOPQRSTUVWYXZ' || x ||
       'abcdefghijklmnopqrstuvwyxz ABCDEFGHIJKLMNOPQRSTUVWYXZ' || x AS y
    FROM t3 LIMIT 1000;
    SELECT x FROM t4 ORDER BY y DESC LIMIT 1 OFFSET 999;
  }
} {1000}






































finish_test







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#    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 LIMIT ... OFFSET ... clause
#  of SELECT statements.
#
# $Id: limit.test,v 1.6 2002/09/08 17:23:45 drh Exp $

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

# Build some test data
#
set fd [open data1.txt w]
................................................................................
       'abcdefghijklmnopqrstuvwyxz ABCDEFGHIJKLMNOPQRSTUVWYXZ' || x ||
       'abcdefghijklmnopqrstuvwyxz ABCDEFGHIJKLMNOPQRSTUVWYXZ' || x AS y
    FROM t3 LIMIT 1000;
    SELECT x FROM t4 ORDER BY y DESC LIMIT 1 OFFSET 999;
  }
} {1000}

do_test limit-5.1 {
  execsql {
    CREATE TABLE t5(x,y);
    INSERT INTO t5 SELECT x-y, x+y FROM t1 WHERE x BETWEEN 10 AND 15
        ORDER BY x LIMIT 2;
    SELECT * FROM t5 ORDER BY x;
  }
} {5 15 6 16}
do_test limit-5.2 {
  execsql {
    DELETE FROM t5;
    INSERT INTO t5 SELECT x-y, x+y FROM t1 WHERE x BETWEEN 10 AND 15
        ORDER BY x DESC LIMIT 2;
    SELECT * FROM t5 ORDER BY x;
  }
} {9 19 10 20}
do_test limit-5.3 {
  execsql {
    DELETE FROM t5;
    INSERT INTO t5 SELECT x-y, x+y FROM t1 WHERE x ORDER BY x DESC LIMIT 31;
    SELECT * FROM t5 ORDER BY x LIMIT 2;
  }
} {-4 6 -3 7}
do_test limit-5.4 {
  execsql {
    SELECT * FROM t5 ORDER BY x DESC, y DESC LIMIT 2;
  }
} {21 41 21 39}
do_test limit-5.5 {
  execsql {
    DELETE FROM t5;
    INSERT INTO t5 SELECT a.x*100+b.x, a.y*100+b.y FROM t1 AS a, t1 AS b
                   ORDER BY 1, 2 LIMIT 1000;
    SELECT count(*), sum(x), sum(y), min(x), max(x), min(y), max(y) FROM t5;
  }
} {1000 1528204 593161 0 3107 505 1005}

finish_test