mirrors/sqlite
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Propagate COLLATE operators upward through function calls and CASE operations.

Browse Source 
And do not flatten an aggregate subquery into a query that uses other
subqueries.  Fixes for tickets [ca0d20b6cdddec5] and
[2f7170d73bf9], respectively.

FossilOrigin-Name: 24e78b8d65734a6a8ae21a20542cd1839e756fb1
This commit is contained in:
drh 2015-02-09 18:28:03 +00:00
commit 6728cd9180
9 changed files with 193 additions and 40 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

27
manifest
View File

@ -1,5 +1,5 @@
C Fix\sWITHOUT\sROWID\stable\shanding\sin\ssqlite3_analyzer.
D 2015-02-09T17:46:11.315
C Propagate\sCOLLATE\soperators\supward\sthrough\sfunction\scalls\sand\sCASE\soperations.\nAnd\sdo\snot\sflatten\san\saggregate\ssubquery\sinto\sa\squery\sthat\suses\sother\nsubqueries.\s\sFixes\sfor\stickets\s[ca0d20b6cdddec5]\sand\n[2f7170d73bf9],\srespectively.
D 2015-02-09T18:28:03.590
F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
F Makefile.in 6b9e7677829aa94b9f30949656e27312aefb9a46
F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@ -181,8 +181,8 @@ F src/callback.c 7b44ce59674338ad48b0e84e7b72f935ea4f68b0
F src/complete.c 198a0066ba60ab06fc00fba1998d870a4d575463
F src/ctime.c 98f89724adc891a1a4c655bee04e33e716e05887
F src/date.c e4d50b3283696836ec1036b695ead9a19e37a5ac
F src/delete.c bd1a91ddd247ce13004075251e0b7fe2bf9925ef
F src/expr.c d66424535d3155eca7f2d8820d26b96870dfcb2d
F src/delete.c 37964e6c1d73ff49cbea9ff690c9605fb15f600e
F src/expr.c 3ef111b88ae2941b84b6b6ea4be8d501ba1af0cb
F src/fault.c 160a0c015b6c2629d3899ed2daf63d75754a32bb
F src/fkey.c e0444b61bed271a76840cbe6182df93a9baa3f12
F src/func.c 6d3c4ebd72aa7923ce9b110a7dc15f9b8c548430
@ -219,7 +219,7 @@ F src/os_win.c 8223e7db5b7c4a81d8b161098ac3959400434cdb
F src/os_win.h eb7a47aa17b26b77eb97e4823f20a00b8bda12ca
F src/pager.c 4120a49ecd37697e28f5ed807f470b9c0b88410c
F src/pager.h c3476e7c89cdf1c6914e50a11f3714e30b4e0a77
F src/parse.y c5d0d964f9ac023e8154cad512e54b0b6058e086
F src/parse.y 0f8e7d60f0ab3cb53d270adef69259ac307d83a8
F src/pcache.c d210cf90d04365a74f85d21374dded65af67b0cb
F src/pcache.h b44658c9c932d203510279439d891a2a83e12ba8
F src/pcache1.c 1e77432b40b7d3288327d9cdf399dcdfd2b6d3bf
@ -230,12 +230,12 @@ F src/printf.c 05edc41450d0eb2c05ef7db113bf32742ae65325
F src/random.c ba2679f80ec82c4190062d756f22d0c358180696
F src/resolve.c f4d79e31ffa5820c2e3d1740baa5e9b190425f2b
F src/rowset.c eccf6af6d620aaa4579bd3b72c1b6395d9e9fa1e
F src/select.c edcf8ba8163526f2340f10f19b0a71547c6f97ba
F src/select.c e46cef4c224549b439384c88fc7f57ba064dad54
F src/shell.c 82c25508dac802b32198af6f5256ca1597c6a1af
F src/sqlite.h.in 54678c21401909f72b221344dd560d285a1ba5eb
F src/sqlite3.rc 992c9f5fb8285ae285d6be28240a7e8d3a7f2bad
F src/sqlite3ext.h 17d487c3c91b0b8c584a32fbeb393f6f795eea7d
F src/sqliteInt.h 436c02d0877b9b9a1c3351717c2c93bd248000e9
F src/sqliteInt.h 57a405ae6d2ed10fff52de376d18f21e04d96609
F src/sqliteLimit.h 164b0e6749d31e0daa1a4589a169d31c0dec7b3d
F src/status.c 81712116e826b0089bb221b018929536b2b5406f
F src/table.c e7a09215315a978057fb42c640f890160dbcc45e
@ -403,7 +403,7 @@ F test/collate4.test f04d5168685f2eef637ecfa2d4ddf8ec0d600177
F test/collate5.test 65d928034d30d2d263a80f6359f7549ee1598ec6
F test/collate6.test 8be65a182abaac8011a622131486dafb8076e907
F test/collate7.test 8ec29d98f3ee4ccebce6e16ce3863fb6b8c7b868
F test/collate8.test df26649cfcbddf109c04122b340301616d3a88f6
F test/collate8.test cd9b3d3f999b8520ffaa7cc1647061fc5bab1334
F test/collate9.test 3adcc799229545940df2f25308dd1ad65869145a
F test/collateA.test b8218ab90d1fa5c59dcf156efabb1b2599c580d6
F test/colmeta.test 2c765ea61ee37bc43bbe6d6047f89004e6508eb1
@ -834,7 +834,7 @@ F test/select2.test 352480e0e9c66eda9c3044e412abdf5be0215b56
F test/select3.test 2ce595f8fb8e2ac10071d3b4e424cadd4634a054
F test/select4.test 8c5a60d439e2df824aed56223566877a883c5c84
F test/select5.test e758b8ef94f69b111df4cb819008856655dcd535
F test/select6.test e76bd10a56988f15726c097a5d5a7966fe82d3b2
F test/select6.test 39eac4a5c03650b2b473c532882273283ee8b7a0
F test/select7.test 7fd2ef598cfabb6b9ff6ac13973b91d0527df49d
F test/select8.test 391de11bdd52339c30580dabbbbe97e3e9a3c79d
F test/select9.test aebc2bb0c3bc44606125033cbcaac2c8d1f33a95
@ -1239,7 +1239,8 @@ F tool/vdbe_profile.tcl 67746953071a9f8f2f668b73fe899074e2c6d8c1
F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
F tool/warnings.sh 0abfd78ceb09b7f7c27c688c8e3fe93268a13b32
F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
P 4ef7ceced2b0000d21f7f8014384c04a0e4661d3
R 3dfd2d57b7936b7d1030a6a9083d3a68
U dan
Z 936b36142dcc1fcccff0b983a2ef7c1f
P 937e0fe7008c0f76b6a584180df9a9457166a0b1 dd8f7f7511639a1baa41a6ff2e359dc6f1e66943
R eaedb0adeed807300663dae355946d49
T +closed dd8f7f7511639a1baa41a6ff2e359dc6f1e66943
U drh
Z 20be3d681a1333c92b781a8eb61382fe

2
manifest.uuid
View File

@ -1 +1 @@
937e0fe7008c0f76b6a584180df9a9457166a0b1
24e78b8d65734a6a8ae21a20542cd1839e756fb1

2
src/delete.c
View File

@ -189,7 +189,7 @@ Expr *sqlite3LimitWhere(
pInClause->x.pSelect = pSelect;
pInClause->flags |= EP_xIsSelect;
sqlite3ExprSetHeight(pParse, pInClause);
sqlite3ExprSetHeightAndFlags(pParse, pInClause);
return pInClause;
/* something went wrong. clean up anything allocated. */

64
src/expr.c
View File

@ -146,10 +146,25 @@ CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr){
break;
}
if( p->flags & EP_Collate ){
if( ALWAYS(p->pLeft) && (p->pLeft->flags & EP_Collate)!=0 ){
if( p->pLeft && (p->pLeft->flags & EP_Collate)!=0 ){
p = p->pLeft;
}else{
p = p->pRight;
Expr *pNext = p->pRight;
/* The Expr.x union is never used at the same time as Expr.pRight */
assert( p->x.pList==0 || p->pRight==0 );
/* p->flags holds EP_Collate and p->pLeft->flags does not. And
** p->x.pSelect cannot. So if p->x.pLeft exists, it must hold at
** least one EP_Collate. Thus the following two ALWAYS. */
if( p->x.pList!=0 && ALWAYS(!ExprHasProperty(p, EP_xIsSelect)) ){
int i;
for(i=0; ALWAYS(i<p->x.pList->nExpr); i++){
if( ExprHasProperty(p->x.pList->a[i].pExpr, EP_Collate) ){
pNext = p->x.pList->a[i].pExpr;
break;
}
}
}
p = pNext;
}
}else{
break;
@ -355,6 +370,9 @@ static void heightOfSelect(Select *p, int *pnHeight){
** Expr.pSelect member has a height of 1. Any other expression
** has a height equal to the maximum height of any other
** referenced Expr plus one.
**
** Also propagate EP_Propagate flags up from Expr.x.pList to Expr.flags,
** if appropriate.
*/
static void exprSetHeight(Expr *p){
int nHeight = 0;
@ -362,8 +380,9 @@ static void exprSetHeight(Expr *p){
heightOfExpr(p->pRight, &nHeight);
if( ExprHasProperty(p, EP_xIsSelect) ){
heightOfSelect(p->x.pSelect, &nHeight);
}else{
}else if( p->x.pList ){
heightOfExprList(p->x.pList, &nHeight);
p->flags |= EP_Propagate & sqlite3ExprListFlags(p->x.pList);
}
p->nHeight = nHeight + 1;
}
@ -372,8 +391,11 @@ static void exprSetHeight(Expr *p){
** Set the Expr.nHeight variable using the exprSetHeight() function. If
** the height is greater than the maximum allowed expression depth,
** leave an error in pParse.
**
** Also propagate all EP_Propagate flags from the Expr.x.pList into
** Expr.flags.
*/
void sqlite3ExprSetHeight(Parse *pParse, Expr *p){
void sqlite3ExprSetHeightAndFlags(Parse *pParse, Expr *p){
exprSetHeight(p);
sqlite3ExprCheckHeight(pParse, p->nHeight);
}
@ -387,8 +409,17 @@ int sqlite3SelectExprHeight(Select *p){
heightOfSelect(p, &nHeight);
return nHeight;
}
#else
#define exprSetHeight(y)
#else /* ABOVE: Height enforcement enabled. BELOW: Height enforcement off */
/*
** Propagate all EP_Propagate flags from the Expr.x.pList into
** Expr.flags.
*/
void sqlite3ExprSetHeightAndFlags(Parse *pParse, Expr *p){
if( p && p->x.pList && !ExprHasProperty(p, EP_xIsSelect) ){
p->flags |= EP_Propagate & sqlite3ExprListFlags(p->x.pList);
}
}
#define exprSetHeight(y)
#endif /* SQLITE_MAX_EXPR_DEPTH>0 */
/*
@ -490,11 +521,11 @@ void sqlite3ExprAttachSubtrees(
}else{
if( pRight ){
pRoot->pRight = pRight;
pRoot->flags |= EP_Collate & pRight->flags;
pRoot->flags |= EP_Propagate & pRight->flags;
}
if( pLeft ){
pRoot->pLeft = pLeft;
pRoot->flags |= EP_Collate & pLeft->flags;
pRoot->flags |= EP_Propagate & pLeft->flags;
}
exprSetHeight(pRoot);
}
@ -594,7 +625,7 @@ Expr *sqlite3ExprFunction(Parse *pParse, ExprList *pList, Token *pToken){
}
pNew->x.pList = pList;
assert( !ExprHasProperty(pNew, EP_xIsSelect) );
sqlite3ExprSetHeight(pParse, pNew);
sqlite3ExprSetHeightAndFlags(pParse, pNew);
return pNew;
}
@ -1209,6 +1240,21 @@ void sqlite3ExprListDelete(sqlite3 *db, ExprList *pList){
sqlite3DbFree(db, pList);
}
/*
** Return the bitwise-OR of all Expr.flags fields in the given
** ExprList.
*/
u32 sqlite3ExprListFlags(const ExprList *pList){
int i;
u32 m = 0;
if( pList ){
for(i=0; i<pList->nExpr; i++){
m |= pList->a[i].pExpr->flags;
}
}
return m;
}
/*
** These routines are Walker callbacks used to check expressions to
** see if they are "constant" for some definition of constant. The

20
src/parse.y
View File

@ -1078,7 +1078,7 @@ expr(A) ::= expr(W) between_op(N) expr(X) AND expr(Y). [BETWEEN] {
A.pExpr = sqlite3PExpr(pParse, TK_IN, X.pExpr, 0, 0);
if( A.pExpr ){
A.pExpr->x.pList = Y;
sqlite3ExprSetHeight(pParse, A.pExpr);
sqlite3ExprSetHeightAndFlags(pParse, A.pExpr);
}else{
sqlite3ExprListDelete(pParse->db, Y);
}
@ -1091,8 +1091,8 @@ expr(A) ::= expr(W) between_op(N) expr(X) AND expr(Y). [BETWEEN] {
A.pExpr = sqlite3PExpr(pParse, TK_SELECT, 0, 0, 0);
if( A.pExpr ){
A.pExpr->x.pSelect = X;
ExprSetProperty(A.pExpr, EP_xIsSelect);
sqlite3ExprSetHeight(pParse, A.pExpr);
ExprSetProperty(A.pExpr, EP_xIsSelect|EP_Subquery);
sqlite3ExprSetHeightAndFlags(pParse, A.pExpr);
}else{
sqlite3SelectDelete(pParse->db, X);
}
@ -1103,8 +1103,8 @@ expr(A) ::= expr(W) between_op(N) expr(X) AND expr(Y). [BETWEEN] {
A.pExpr = sqlite3PExpr(pParse, TK_IN, X.pExpr, 0, 0);
if( A.pExpr ){
A.pExpr->x.pSelect = Y;
ExprSetProperty(A.pExpr, EP_xIsSelect);
sqlite3ExprSetHeight(pParse, A.pExpr);
ExprSetProperty(A.pExpr, EP_xIsSelect|EP_Subquery);
sqlite3ExprSetHeightAndFlags(pParse, A.pExpr);
}else{
sqlite3SelectDelete(pParse->db, Y);
}
@ -1117,8 +1117,8 @@ expr(A) ::= expr(W) between_op(N) expr(X) AND expr(Y). [BETWEEN] {
A.pExpr = sqlite3PExpr(pParse, TK_IN, X.pExpr, 0, 0);
if( A.pExpr ){
A.pExpr->x.pSelect = sqlite3SelectNew(pParse, 0,pSrc,0,0,0,0,0,0,0);
ExprSetProperty(A.pExpr, EP_xIsSelect);
sqlite3ExprSetHeight(pParse, A.pExpr);
ExprSetProperty(A.pExpr, EP_xIsSelect|EP_Subquery);
sqlite3ExprSetHeightAndFlags(pParse, A.pExpr);
}else{
sqlite3SrcListDelete(pParse->db, pSrc);
}
@ -1130,8 +1130,8 @@ expr(A) ::= expr(W) between_op(N) expr(X) AND expr(Y). [BETWEEN] {
Expr *p = A.pExpr = sqlite3PExpr(pParse, TK_EXISTS, 0, 0, 0);
if( p ){
p->x.pSelect = Y;
ExprSetProperty(p, EP_xIsSelect);
sqlite3ExprSetHeight(pParse, p);
ExprSetProperty(p, EP_xIsSelect|EP_Subquery);
sqlite3ExprSetHeightAndFlags(pParse, p);
}else{
sqlite3SelectDelete(pParse->db, Y);
}
@ -1145,7 +1145,7 @@ expr(A) ::= CASE(C) case_operand(X) case_exprlist(Y) case_else(Z) END(E). {
A.pExpr = sqlite3PExpr(pParse, TK_CASE, X, 0, 0);
if( A.pExpr ){
A.pExpr->x.pList = Z ? sqlite3ExprListAppend(pParse,Y,Z) : Y;
sqlite3ExprSetHeight(pParse, A.pExpr);
sqlite3ExprSetHeightAndFlags(pParse, A.pExpr);
}else{
sqlite3ExprListDelete(pParse->db, Y);
sqlite3ExprDelete(pParse->db, Z);

18
src/select.c
View File

@ -3194,7 +3194,10 @@ static void substSelect(
**
** (1) The subquery and the outer query do not both use aggregates.
**
** (2) The subquery is not an aggregate or the outer query is not a join.
** (2) The subquery is not an aggregate or (2a) the outer query is not a join
** and (2b) the outer query does not use subqueries other than the one
** FROM-clause subquery that is a candidate for flattening. (2b is
** due to ticket [2f7170d73bf9abf80] from 2015-02-09.)
**
** (3) The subquery is not the right operand of a left outer join
** (Originally ticket #306. Strengthened by ticket #3300)
@ -3331,8 +3334,17 @@ static int flattenSubquery(
iParent = pSubitem->iCursor;
pSub = pSubitem->pSelect;
assert( pSub!=0 );
if( isAgg && subqueryIsAgg ) return 0; /* Restriction (1) */
if( subqueryIsAgg && pSrc->nSrc>1 ) return 0; /* Restriction (2) */
if( subqueryIsAgg ){
if( isAgg ) return 0; /* Restriction (1) */
if( pSrc->nSrc>1 ) return 0; /* Restriction (2a) */
if( (p->pWhere && ExprHasProperty(p->pWhere,EP_Subquery))
|| (sqlite3ExprListFlags(p->pEList) & EP_Subquery)!=0
|| (sqlite3ExprListFlags(p->pOrderBy) & EP_Subquery)!=0
){
return 0; /* Restriction (2b) */
}
}
pSubSrc = pSub->pSrc;
assert( pSubSrc );
/* Prior to version 3.1.2, when LIMIT and OFFSET had to be simple constants,

10
src/sqliteInt.h
View File

@ -2046,6 +2046,12 @@ struct Expr {
#define EP_Unlikely 0x040000 /* unlikely() or likelihood() function */
#define EP_ConstFunc 0x080000 /* Node is a SQLITE_FUNC_CONSTANT function */
#define EP_CanBeNull 0x100000 /* Can be null despite NOT NULL constraint */
#define EP_Subquery 0x200000 /* Tree contains a TK_SELECT operator */
/*
** Combinations of two or more EP_* flags
*/
#define EP_Propagate (EP_Collate|EP_Subquery) /* Propagate these bits up tree */
/*
** These macros can be used to test, set, or clear bits in the
@ -3153,6 +3159,7 @@ ExprList *sqlite3ExprListAppend(Parse*,ExprList*,Expr*);
void sqlite3ExprListSetName(Parse*,ExprList*,Token*,int);
void sqlite3ExprListSetSpan(Parse*,ExprList*,ExprSpan*);
void sqlite3ExprListDelete(sqlite3*, ExprList*);
u32 sqlite3ExprListFlags(const ExprList*);
int sqlite3Init(sqlite3*, char**);
int sqlite3InitCallback(void*, int, char**, char**);
void sqlite3Pragma(Parse*,Token*,Token*,Token*,int);
@ -3736,12 +3743,11 @@ void sqlite3MemJournalOpen(sqlite3_file *);
int sqlite3MemJournalSize(void);
int sqlite3IsMemJournal(sqlite3_file *);
void sqlite3ExprSetHeightAndFlags(Parse *pParse, Expr *p);
#if SQLITE_MAX_EXPR_DEPTH>0
void sqlite3ExprSetHeight(Parse *pParse, Expr *p);
int sqlite3SelectExprHeight(Select *);
int sqlite3ExprCheckHeight(Parse*, int);
#else
#define sqlite3ExprSetHeight(x,y)
#define sqlite3SelectExprHeight(x) 0
#define sqlite3ExprCheckHeight(x,y)
#endif

34
test/collate8.test
View File

@ -13,7 +13,9 @@
# focus of this script is making sure collations pass through the
# unary + operator.
#
# $Id: collate8.test,v 1.2 2008/08/25 12:14:09 drh Exp $
# 2015-02-09: Added tests to make sure COLLATE passes through function
# calls. Ticket [ca0d20b6cdddec5e81b8d66f89c46a5583b5f6f6].
#
set testdir [file dirname $argv0]
source $testdir/tester.tcl
@ -122,4 +124,34 @@ do_test collate8-2.8 {
}
} {abc}
# Make sure the COLLATE operator perculates up through function calls
# and other Expr structures that use the Expr.x.pList field.
#
do_execsql_test collate8-3.1 {
SELECT 'abc'==('ABC'||'') COLLATE nocase;
SELECT 'abc'==('ABC'||'' COLLATE nocase);
SELECT 'abc'==('ABC'||('' COLLATE nocase));
SELECT 'abc'==('ABC'||upper('' COLLATE nocase));
} {1 1 1 1}
do_execsql_test collate8-3.2 {
SELECT 'abc'==('ABC'||max('' COLLATE nocase,'' COLLATE binary));
} {1}
# The COLLATE binary is on the left and so takes precedence
do_execsql_test collate8-3.3 {
SELECT 'abc'==('ABC'||max('' COLLATE binary,'' COLLATE nocase));
} {0}
do_execsql_test collate8-3.4 {
SELECT 'abc'==('ABC'||CASE WHEN 1-1=2 THEN '' COLLATE nocase
ELSE '' COLLATE binary END);
SELECT 'abc'==('ABC'||CASE WHEN 1+1=2 THEN '' COLLATE nocase
ELSE '' COLLATE binary END);
} {1 1}
do_execsql_test collate8-3.5 {
SELECT 'abc'==('ABC'||CASE WHEN 1=2 THEN '' COLLATE binary
ELSE '' COLLATE nocase END);
} {0}
finish_test

56
test/select6.test
View File

@ -557,5 +557,61 @@ do_catchsql_test 10.8 {
)
} $err
# 2015-02-09 Ticket [2f7170d73bf9abf80339187aa3677dce3dbcd5ca]
# "misuse of aggregate" error if aggregate column from FROM
# subquery is used in correlated subquery
#
do_execsql_test 11.1 {
DROP TABLE IF EXISTS t1;
CREATE TABLE t1(w INT, x INT);
INSERT INTO t1(w,x)
VALUES(1,10),(2,20),(3,30),
(2,21),(3,31),
(3,32);
CREATE INDEX t1wx ON t1(w,x);
DROP TABLE IF EXISTS t2;
CREATE TABLE t2(w INT, y VARCHAR(8));
INSERT INTO t2(w,y) VALUES(1,'one'),(2,'two'),(3,'three'),(4,'four');
CREATE INDEX t2wy ON t2(w,y);
SELECT cnt, xyz, (SELECT y FROM t2 WHERE w=cnt), '|'
FROM (SELECT count(*) AS cnt, w AS xyz FROM t1 GROUP BY 2)
ORDER BY cnt, xyz;
} {1 1 one | 2 2 two | 3 3 three |}
do_execsql_test 11.2 {
SELECT cnt, xyz, lower((SELECT y FROM t2 WHERE w=cnt)), '|'
FROM (SELECT count(*) AS cnt, w AS xyz FROM t1 GROUP BY 2)
ORDER BY cnt, xyz;
} {1 1 one | 2 2 two | 3 3 three |}
do_execsql_test 11.3 {
SELECT cnt, xyz, '|'
FROM (SELECT count(*) AS cnt, w AS xyz FROM t1 GROUP BY 2)
WHERE (SELECT y FROM t2 WHERE w=cnt)!='two'
ORDER BY cnt, xyz;
} {1 1 | 3 3 |}
do_execsql_test 11.4 {
SELECT cnt, xyz, '|'
FROM (SELECT count(*) AS cnt, w AS xyz FROM t1 GROUP BY 2)
ORDER BY lower((SELECT y FROM t2 WHERE w=cnt));
} {1 1 | 3 3 | 2 2 |}
do_execsql_test 11.5 {
SELECT cnt, xyz,
CASE WHEN (SELECT y FROM t2 WHERE w=cnt)=='two'
THEN 'aaa' ELSE 'bbb'
END, '|'
FROM (SELECT count(*) AS cnt, w AS xyz FROM t1 GROUP BY 2)
ORDER BY +cnt;
} {1 1 bbb | 2 2 aaa | 3 3 bbb |}
do_execsql_test 11.100 {
DROP TABLE t1;
DROP TABLE t2;
CREATE TABLE t1(x);
CREATE TABLE t2(y, z);
SELECT ( SELECT y FROM t2 WHERE z = cnt )
FROM ( SELECT count(*) AS cnt FROM t1 );
} {{}}
finish_test