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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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22
manifest
View File

@ -1,5 +1,5 @@
C Improvements\sto\scomments.\s\sNo\scode\schanges.\s(CVS\s618)
D 2002-06-14T20:58:45
C Make\sthe\sLIMIT\sclause\swork\seven\sif\sthe\sdestination\sof\sthe\sSELECT\sis\nsomething\sother\sthan\sa\scallback.\s\s(Ticket\s#66)\s(CVS\s619)
D 2002-06-14T22:38:42
F Makefile.in 6291a33b87d2a395aafd7646ee1ed562c6f2c28c
F Makefile.template 4e11752e0b5c7a043ca50af4296ec562857ba495
F README a4c0ba11354ef6ba0776b400d057c59da47a4cc0
@ -37,7 +37,7 @@ F src/pager.h 6fddfddd3b73aa8abc081b973886320e3c614f0e
F src/parse.y 42920305d49666419358b469e4ec522ac867a39f
F src/printf.c d8032ee18b860c812eeff596c9bebfdacb7930fd
F src/random.c 19e8e00fe0df32a742f115773f57651be327cabe
F src/select.c 1d5cb1ae0bb3376bedfde7ae22e6e927e4d0b5e2
F src/select.c 6c3a92d7a0bdf3448265d530cc0e6f6e5a764997
F src/shell.c 1d22fe870ee852cfb975fd000dbe3973713d0a15
F src/shell.tcl 27ecbd63dd88396ad16d81ab44f73e6c0ea9d20e
F src/sqlite.h.in 0038faa6d642de06b91143ee65a131bd831d020b
@ -52,9 +52,9 @@ F src/tokenize.c 890ca022d45f1798dadc300a798951597428853e
F src/trigger.c 21342af6ac031fece39c8fc6eabd1739ca5327c1
F src/update.c 05431e23a9c83502fd7911e771c8366fc2b90b4c
F src/util.c 876b259f9186e84b944b72e793dd3dad50e63e95
F src/vdbe.c 836f2c4f823c94c3c3454125d9ba9283e8b22dda
F src/vdbe.h 1742d6f8b40f40879475b4c41cf4f9980ceb0e21
F src/where.c bd25559800ba1fbe1fd596eaec14c417aa1e1b46
F src/vdbe.c 7d9bb3701ea00576c5d5fb3f3de63af7b7304241
F src/vdbe.h fba15f3280688f6f32f11d1042078e3c557bac43
F src/where.c aa5d9d83abf0f7dda06fdd4235020f2b72d58dec
F test/all.test e4d3821eeba751829b419cd47814bd20af4286d1
F test/bigrow.test 8ab252dba108f12ad64e337b0f2ff31a807ac578
F test/btree.test bf326f546a666617367a7033fa2c07451bd4f8e1
@ -72,7 +72,7 @@ F test/insert2.test eb8481878a7f52ccb4e3346f87550f5afdd77f76
F test/intpkey.test 31b5f28b2c44273e6695cf36ab2e4133aee7753c
F test/ioerr.test 57d9bffaca18b34f9e976f786eadc2591d6efc6a
F test/join.test ea6a4097e4fcebbb16eac7ec819569e759336a74
F test/limit.test 6f98bcefc92209103bb3764c81975a6ec21d6702
F test/limit.test 96b33e108e134b5cc674a660064229d15fa278b9
F test/lock.test 3fcfd46a73119f6a18094673328a32c7b3047a8f
F test/main.test c66b564554b770ee7fdbf6a66c0cd90329bc2c85
F test/malloc.test 7ba32a9ebd3aeed52ae4aaa6d42ca37e444536fd
@ -108,7 +108,7 @@ F test/unique.test 572aa791327c1e8d797932263e9d67f176cfdb44
F test/update.test a0aa0bf83e6fad8407d0e4ad25ebb09b513f5bf4
F test/vacuum.test 059871b312eb910bbe49dafde1d01490cc2c6bbe
F test/view.test b9851e9142de5e5831fdf18f125cbe1256cb550a
F test/where.test fe33c2f92de1da8192abf763a2852a4ba270fefe
F test/where.test 367d7911ee0522f1bb8a2daf17fb985e06cfe8bb
F tool/lemon.c 459cb2bb3738a1ad5cb0ad8b805587a88a885d95
F tool/lempar.c 73a991cc3017fb34804250fa901488b5147b3717
F tool/memleak.awk 296dfbce7a9ca499b95ce04e30334e64a50052e0
@ -137,7 +137,7 @@ F www/speed.tcl da8afcc1d3ccc5696cfb388a68982bc3d9f7f00f
F www/sqlite.tcl 8b5884354cb615049aed83039f8dfe1552a44279
F www/tclsqlite.tcl 1db15abeb446aad0caf0b95b8b9579720e4ea331
F www/vdbe.tcl 2013852c27a02a091d39a766bc87cff329f21218
P e67ac0fec51788aca0429d04310f86c9c1cf9d13
R c5c72185b42e3894c8a67dc4dc44e497
P 7e10e60bb78b680bb822908a0b7763f8f5e3ee5a
R 93cd20298bab2e582d79237e05fbb947
U drh
Z ec1b6ad2227bde141b128cfba4f6e91b
Z 34cf64c3405f1f55004d8bc22fcb2d56

2
manifest.uuid
View File

@ -1 +1 @@
7e10e60bb78b680bb822908a0b7763f8f5e3ee5a
699cf362083043615eb88635a228bfa46a315c9c

71
src/select.c
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@ -12,7 +12,7 @@
** This file contains C code routines that are called by the parser
** to handle SELECT statements in SQLite.
**
** $Id: select.c,v 1.92 2002/06/06 23:42:28 drh Exp $
** $Id: select.c,v 1.93 2002/06/14 22:38:42 drh Exp $
*/
#include "sqliteInt.h"
@ -294,6 +294,7 @@ static void sqliteAggregateInfoReset(Parse *pParse){
*/
static int selectInnerLoop(
Parse *pParse, /* The parser context */
Select *p, /* The complete select statement being coded */
ExprList *pEList, /* List of values being extracted */
int srcTab, /* Pull data from this table */
int nColumn, /* Number of columns in the source table */
@ -308,6 +309,18 @@ static int selectInnerLoop(
int i;
if( v==0 ) return 0;
/* If there was a LIMIT clause on the SELECT statement, then do the check
** to see if this row should be output.
*/
if( pOrderBy==0 ){
if( p->nOffset>0 ){
sqliteVdbeAddOp(v, OP_LimitCk, 1, iContinue);
}
if( p->nLimit>0 ){
sqliteVdbeAddOp(v, OP_LimitCk, 0, iBreak);
}
}
/* Pull the requested columns.
*/
if( pEList ){
@ -419,7 +432,8 @@ static int selectInnerLoop(
/* If none of the above, send the data to the callback function.
*/
{
sqliteVdbeAddOp(v, OP_Callback, nColumn, iBreak);
assert( eDest==SRT_Callback );
sqliteVdbeAddOp(v, OP_Callback, nColumn, 0);
}
return 0;
}
@ -430,12 +444,18 @@ static int selectInnerLoop(
** we need to run the sorter and output the results. The following
** routine generates the code needed to do that.
*/
static void generateSortTail(Vdbe *v, int nColumn){
static void generateSortTail(Select *p, Vdbe *v, int nColumn){
int end = sqliteVdbeMakeLabel(v);
int addr;
sqliteVdbeAddOp(v, OP_Sort, 0, 0);
addr = sqliteVdbeAddOp(v, OP_SortNext, 0, end);
sqliteVdbeAddOp(v, OP_SortCallback, nColumn, end);
if( p->nOffset>0 ){
sqliteVdbeAddOp(v, OP_LimitCk, 1, addr);
}
if( p->nLimit>0 ){
sqliteVdbeAddOp(v, OP_LimitCk, 0, end);
}
sqliteVdbeAddOp(v, OP_SortCallback, nColumn, 0);
sqliteVdbeAddOp(v, OP_Goto, 0, addr);
sqliteVdbeResolveLabel(v, end);
sqliteVdbeAddOp(v, OP_SortReset, 0, 0);
@ -975,7 +995,7 @@ static int multiSelect(Parse *pParse, Select *p, int eDest, int iParm){
iCont = sqliteVdbeMakeLabel(v);
sqliteVdbeAddOp(v, OP_Rewind, unionTab, iBreak);
iStart = sqliteVdbeCurrentAddr(v);
rc = selectInnerLoop(pParse, 0, unionTab, p->pEList->nExpr,
rc = selectInnerLoop(pParse, p, 0, unionTab, p->pEList->nExpr,
p->pOrderBy, -1, eDest, iParm,
iCont, iBreak);
if( rc ) return 1;
@ -984,7 +1004,7 @@ static int multiSelect(Parse *pParse, Select *p, int eDest, int iParm){
sqliteVdbeResolveLabel(v, iBreak);
sqliteVdbeAddOp(v, OP_Close, unionTab, 0);
if( p->pOrderBy ){
generateSortTail(v, p->pEList->nExpr);
generateSortTail(p, v, p->pEList->nExpr);
}
}
break;
@ -1031,7 +1051,7 @@ static int multiSelect(Parse *pParse, Select *p, int eDest, int iParm){
sqliteVdbeAddOp(v, OP_Rewind, tab1, iBreak);
iStart = sqliteVdbeAddOp(v, OP_FullKey, tab1, 0);
sqliteVdbeAddOp(v, OP_NotFound, tab2, iCont);
rc = selectInnerLoop(pParse, 0, tab1, p->pEList->nExpr,
rc = selectInnerLoop(pParse, p, 0, tab1, p->pEList->nExpr,
p->pOrderBy, -1, eDest, iParm,
iCont, iBreak);
if( rc ) return 1;
@ -1041,7 +1061,7 @@ static int multiSelect(Parse *pParse, Select *p, int eDest, int iParm){
sqliteVdbeAddOp(v, OP_Close, tab2, 0);
sqliteVdbeAddOp(v, OP_Close, tab1, 0);
if( p->pOrderBy ){
generateSortTail(v, p->pEList->nExpr);
generateSortTail(p, v, p->pEList->nExpr);
}
break;
}
@ -1176,6 +1196,14 @@ substExprList(ExprList *pList, int iTable, ExprList *pEList, int iSub){
**
** (7) The subquery has a FROM clause.
**
** (8) The subquery does not use LIMIT or the outer query is not a join.
**
** (9) The subquery does not use LIMIT or the outer query does not use
** aggregates.
**
** (10) The subquery does not use aggregates or the outer query does not
** use LIMIT.
**
** In this routine, the "p" parameter is a pointer to the outer query.
** The subquery is p->pSrc->a[iFrom]. isAgg is true if the outer query
** uses aggregates and subqueryIsAgg is true if the subquery uses aggregates.
@ -1207,9 +1235,10 @@ int flattenSubquery(Select *p, int iFrom, int isAgg, int subqueryIsAgg){
pSubSrc = pSub->pSrc;
assert( pSubSrc );
if( pSubSrc->nSrc!=1 ) return 0;
if( pSub->isDistinct && pSrc->nSrc>1 ) return 0;
if( pSub->isDistinct && isAgg ) return 0;
if( p->isDistinct && subqueryIsAgg ) return 0;
if( (pSub->isDistinct || pSub->nLimit>=0) && (pSrc->nSrc>1 || isAgg) ){
return 0;
}
if( (p->isDistinct || p->nLimit) && subqueryIsAgg ) return 0;
/* If we reach this point, it means flattening is permitted for the
** i-th entry of the FROM clause in the outer query.
@ -1267,6 +1296,14 @@ int flattenSubquery(Select *p, int iFrom, int isAgg, int subqueryIsAgg){
}
}
p->isDistinct = p->isDistinct || pSub->isDistinct;
if( pSub->nLimit>=0 ){
if( p->nLimit<0 ){
p->nLimit = pSub->nLimit;
}else if( p->nLimit+p->nOffset > pSub->nLimit+pSub->nOffset ){
p->nLimit = pSub->nLimit + pSub->nOffset - p->nOffset;
}
}
p->nOffset += pSub->nOffset;
if( pSrc->a[iFrom].pTab && pSrc->a[iFrom].pTab->isTransient ){
sqliteDeleteTable(0, pSrc->a[iFrom].pTab);
}
@ -1386,7 +1423,7 @@ static int simpleMinMaxQuery(Parse *pParse, Select *p, int eDest, int iParm){
eList.a = &eListItem;
eList.a[0].pExpr = pExpr;
cont = sqliteVdbeMakeLabel(v);
selectInnerLoop(pParse, &eList, base, 1, 0, -1, eDest, iParm, cont, cont);
selectInnerLoop(pParse, p, &eList, base, 1, 0, -1, eDest, iParm, cont, cont);
sqliteVdbeResolveLabel(v, cont);
sqliteVdbeAddOp(v, OP_Close, base, 0);
return 1;
@ -1720,8 +1757,8 @@ int sqliteSelect(
** aggregates
*/
if( !isAgg ){
if( selectInnerLoop(pParse, pEList, 0, 0, pOrderBy, distinct, eDest, iParm,
pWInfo->iContinue, pWInfo->iBreak) ){
if( selectInnerLoop(pParse, p, pEList, 0, 0, pOrderBy, distinct, eDest,
iParm, pWInfo->iContinue, pWInfo->iBreak) ){
goto select_end;
}
}
@ -1779,8 +1816,8 @@ int sqliteSelect(
if( pHaving ){
sqliteExprIfFalse(pParse, pHaving, startagg, 1);
}
if( selectInnerLoop(pParse, pEList, 0, 0, pOrderBy, distinct, eDest, iParm,
startagg, endagg) ){
if( selectInnerLoop(pParse, p, pEList, 0, 0, pOrderBy, distinct, eDest,
iParm, startagg, endagg) ){
goto select_end;
}
sqliteVdbeAddOp(v, OP_Goto, 0, startagg);
@ -1793,7 +1830,7 @@ int sqliteSelect(
** and send them to the callback one by one.
*/
if( pOrderBy ){
generateSortTail(v, pEList->nExpr);
generateSortTail(p, v, pEList->nExpr);
}

71
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;
}
}
}
}
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
@ -4207,41 +4220,23 @@ 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;
}
}
}
p->nCallback++;
}
POPSTACK;
if( sqlite_malloc_failed ) goto no_mem;

5
src/vdbe.h
View File

@ -15,7 +15,7 @@
** or VDBE. The VDBE implements an abstract machine that runs a
** simple program to access and modify the underlying database.
**
** $Id: vdbe.h,v 1.54 2002/06/08 23:25:09 drh Exp $
** $Id: vdbe.h,v 1.55 2002/06/14 22:38:43 drh Exp $
*/
#ifndef _SQLITE_VDBE_H_
#define _SQLITE_VDBE_H_
@ -204,9 +204,10 @@ typedef struct VdbeOp VdbeOp;
#define OP_Function 119
#define OP_Limit 120
#define OP_LimitCk 121
#define OP_MAX 120
#define OP_MAX 121
/*
** Prototypes for the VDBE interface. See comments on the implementation

3
src/where.c
View File

@ -13,7 +13,7 @@
** the WHERE clause of SQL statements. Also found here are subroutines
** to generate VDBE code to evaluate expressions.
**
** $Id: where.c,v 1.51 2002/06/14 20:58:45 drh Exp $
** $Id: where.c,v 1.52 2002/06/14 22:38:43 drh Exp $
*/
#include "sqliteInt.h"
@ -258,6 +258,7 @@ WhereInfo *sqliteWhereBegin(
*/
if( pWhere && sqliteExprIsConstant(pWhere) ){
sqliteExprIfFalse(pParse, pWhere, pWInfo->iBreak, 1);
pWhere = 0;
}
/* Split the WHERE clause into as many as 32 separate subexpressions

20
test/limit.test
View File

@ -12,7 +12,7 @@
# focus of this file is testing the LIMIT ... OFFSET ... clause
# of SELECT statements.
#
# $Id: limit.test,v 1.2 2002/05/24 16:14:16 drh Exp $
# $Id: limit.test,v 1.3 2002/06/14 22:38:43 drh Exp $
set testdir [file dirname $argv0]
source $testdir/tester.tcl
@ -56,5 +56,23 @@ do_test limit-1.7 {
execsql {SELECT * FROM t1 AS a, t1 AS b ORDER BY a.x, b.x LIMIT 5 OFFSET 32}
} {1 5 0 5 1 5 1 5 1 5 2 5 1 5 3 5 1 5 4 5}
do_test limit-2.1 {
execsql {
CREATE VIEW v1 AS SELECT * FROM t1 LIMIT 2;
SELECT count(*) FROM (SELECT * FROM v1);
}
} 2
do_test limit-2.2 {
execsql {
CREATE TABLE t2 AS SELECT * FROM t1 LIMIT 2;
SELECT count(*) FROM t2;
}
} 2
do_test limit-2.3 {
execsql {
SELECT count(*) FROM t1 WHERE rowid IN (SELECT rowid FROM t1 LIMIT 2);
}
} 2
finish_test

4
test/where.test
View File

@ -11,7 +11,7 @@
# 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 1.7 2002/06/09 01:55:20 drh Exp $
# $Id: where.test,v 1.8 2002/06/14 22:38:43 drh Exp $
set testdir [file dirname $argv0]
source $testdir/tester.tcl
@ -249,7 +249,7 @@ do_test where-4.2 {
count {
SELECT * FROM t1 WHERE 1 LIMIT 1
}
} {1 0 4 0}
} {1 0 4 1}
do_test where-4.3 {
execsql {
SELECT 99 WHERE 0