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Make the LIMIT clause work even if the destination of the SELECT is

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something other than a callback.  (Ticket #66) (CVS 619)

FossilOrigin-Name: 699cf362083043615eb88635a228bfa46a315c9c
This commit is contained in:
drh
2002-06-14 22:38:41 +00:00
parent c27a1ce4bd
commit df199a25bd
8 changed files with 134 additions and 82 deletions
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89
src/vdbe.c
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@@ -30,7 +30,7 @@
** But other routines are also provided to help in building up
** a program instruction by instruction.
**
** $Id: vdbe.c,v 1.155 2002/06/11 02:25:42 danielk1977 Exp $
** $Id: vdbe.c,v 1.156 2002/06/14 22:38:43 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
@@ -1080,6 +1080,7 @@ static char *zOpName[] = { 0,
"Gt", "Ge", "IsNull", "NotNull",
"Negative", "And", "Or", "Not",
"Concat", "Noop", "Function", "Limit",
"LimitCk",
};
/*
@@ -1585,18 +1586,11 @@ case OP_ColumnName: {
break;
}
/* Opcode: Callback P1 P2 *
/* Opcode: Callback P1 * *
**
** Pop P1 values off the stack and form them into an array. Then
** invoke the callback function using the newly formed array as the
** 3rd parameter.
**
** If the offset counter (set by the OP_Limit opcode) is positive,
** then decrement the counter and do not invoke the callback.
**
** If the callback is invoked, then after the callback returns
** decrement the limit counter. When the limit counter reaches
** zero, jump to address P2.
*/
case OP_Callback: {
int i = p->tos - pOp->p1 + 1;
@@ -1612,22 +1606,12 @@ case OP_Callback: {
}
zStack[p->tos+1] = 0;
if( xCallback!=0 ){
if( p->iOffset>0 ){
p->iOffset--;
}else{
if( sqliteSafetyOff(db) ) goto abort_due_to_misuse;
if( xCallback(pArg, pOp->p1, &zStack[i], p->azColName)!=0 ){
rc = SQLITE_ABORT;
}
if( sqliteSafetyOn(db) ) goto abort_due_to_misuse;
p->nCallback++;
if( p->iLimit>0 ){
p->iLimit--;
if( p->iLimit==0 ){
pc = pOp->p2 - 1;
}
}
if( sqliteSafetyOff(db) ) goto abort_due_to_misuse;
if( xCallback(pArg, pOp->p1, &zStack[i], p->azColName)!=0 ){
rc = SQLITE_ABORT;
}
if( sqliteSafetyOn(db) ) goto abort_due_to_misuse;
p->nCallback++;
}
PopStack(p, pOp->p1);
if( sqlite_malloc_failed ) goto no_mem;
@@ -3917,6 +3901,35 @@ case OP_Limit: {
break;
}
/* Opcode: LimitCk P1 P2 *
**
** If P1 is 1, then check to see if the offset counter (set by the
** P2 argument of OP_Limit) is positive. If the offset counter is
** positive then decrement the counter and jump immediately to P2.
** Otherwise fall straight through.
**
** If P1 is 0, then check the value of the limit counter (set by the
** P1 argument of OP_Limit). If the limit counter is negative or
** zero then jump immedately to P2. Otherwise decrement the limit
** counter and fall through.
*/
case OP_LimitCk: {
if( pOp->p1 ){
if( p->iOffset ){
p->iOffset--;
pc = pOp->p2 - 1;
}
}else{
if( p->iLimit>0 ){
p->iLimit--;
}else{
pc = pOp->p2 - 1;
}
}
break;
}
/* Opcode: ListWrite * * *
**
** Write the integer on the top of the stack
@@ -4207,40 +4220,22 @@ case OP_SortNext: {
break;
}
/* Opcode: SortCallback P1 P2 *
/* 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.
**
** If the offset counter (set by the OP_Limit opcode) is positive,
** then decrement the counter and do not invoke the callback.
**
** If the callback is invoked, then after the callback returns
** decrement the limit counter. When the limit counter reaches
** zero, jump to address P2.
*/
case OP_SortCallback: {
int i = p->tos;
VERIFY( if( i<0 ) goto not_enough_stack; )
if( xCallback!=0 ){
if( p->iOffset>0 ){
p->iOffset--;
}else{
if( sqliteSafetyOff(db) ) goto abort_due_to_misuse;
if( xCallback(pArg, pOp->p1, (char**)zStack[i], p->azColName)!=0 ){
rc = SQLITE_ABORT;
}
if( sqliteSafetyOn(db) ) goto abort_due_to_misuse;
p->nCallback++;
if( p->iLimit>0 ){
p->iLimit--;
if( p->iLimit==0 ){
pc = pOp->p2 - 1;
}
}
if( sqliteSafetyOff(db) ) goto abort_due_to_misuse;
if( xCallback(pArg, pOp->p1, (char**)zStack[i], p->azColName)!=0 ){
rc = SQLITE_ABORT;
}
if( sqliteSafetyOn(db) ) goto abort_due_to_misuse;
p->nCallback++;
}
POPSTACK;