-C New\stest\scases\sadded.
-D 2022-04-11T18:54:23.445
+C The\squery\sflattener\smust\sadd\sTK_IF_NULL_ROW\sopcodes\son\ssubstituted\svalues\nthat\sland\son\sthe\sleft\soperand\sof\sa\sRIGHT\sJOIN,\sjust\sas\sit\salready\sdoes\sfor\nthe\sright\soperand\sof\sa\sLEFT\sJOIN.
+D 2022-04-11T20:15:52.179
F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
F src/random.c 097dc8b31b8fba5a9aca1697aeb9fd82078ec91be734c16bffda620ced7ab83c
F src/resolve.c 7110fc3b5a4dec5d11559141c1906c4a125349fb602f541b05db3a3d448d4b95
F src/rowset.c ba9515a922af32abe1f7d39406b9d35730ed65efab9443dc5702693b60854c92
-F src/select.c 67d793d9d3008699bc67a079de9eafc0c07d84c12fb867e5b735a79a456a77cb
+F src/select.c fdec126045cf441883836756d6d949367e8a2945c53fa6e98d6c51a08d7efc81
F src/shell.c.in eb7f10d5e2c47bd014d92ec5db1def21fcc1ed56ffaaa4ee715b6c37c370b47f
F src/sqlite.h.in 2a35f62185eb5e7ecc64a2f68442b538ce9be74f80f28a00abc24837edcf1c17
F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P b6e773a26c2c6ee76ea61acb059b4e676d07ea62f6db9c513638f8986557cf04
-R ea6a6206ccd15b1ede34fe0a185bc5f1
+P bdd1499c0fa4f8aadf4857a0ccc0d839c250369f29766ebef80330964905e63b
+R 1528160c8ffde5ccc7d4edc8311e6b3e
U drh
-Z 7ac11620004b739208f6ff19e0608f85
+Z 0a6599330cad92a7a73b62ce77e2586b
# Remove this line to create a well-formed Fossil manifest.
**
** All references to columns in table iTable are to be replaced by corresponding
** expressions in pEList.
+**
+** ## About "isOuterJoin":
+**
+** The isOuterJoin column indicates that the replacement will occur into a
+** position in the parent that NULL-able due to an OUTER JOIN. Either the
+** target slot in the parent is the right operand of a LEFT JOIN, or one of
+** the left operands of a RIGHT JOIN. In either case, we need to potentially
+** bypass the substituted expression with OP_IfNullRow.
+**
+** Suppose the original expression integer constant. Even though the table
+** has the nullRow flag set, because the expression is an integer constant,
+** it will not be NULLed out. So instead, we insert an OP_IfNullRow opcode
+** that checks to see if the nullRow flag is set on the table. If the nullRow
+** flag is set, then the value in the register is set to NULL and the original
+** expression is bypassed. If the nullRow flag is not set, then the original
+** expression runs to populate the register.
+**
+** Example where this is needed:
+**
+** CREATE TABLE t1(a INTEGER PRIMARY KEY, b INT);
+** CREATE TABLE t2(x INT UNIQUE);
+**
+** SELECT a,b,m,x FROM t1 LEFT JOIN (SELECT 59 AS m,x FROM t2) ON b=x;
+**
+** When the subquery on the right side of the LEFT JOIN is flattened, we
+** have to add OP_IfNullRow in front of the OP_Integer that implements the
+** "m" value of the subquery so that a NULL will be loaded instead of 59
+** when processing a non-matched row of the left.
*/
typedef struct SubstContext {
Parse *pParse; /* The parsing context */
int iTable; /* Replace references to this table */
int iNewTable; /* New table number */
- int isLeftJoin; /* Add TK_IF_NULL_ROW opcodes on each replacement */
+ int isOuterJoin; /* Add TK_IF_NULL_ROW opcodes on each replacement */
ExprList *pEList; /* Replacement expressions */
} SubstContext;
sqlite3VectorErrorMsg(pSubst->pParse, pCopy);
}else{
sqlite3 *db = pSubst->pParse->db;
- if( pSubst->isLeftJoin && pCopy->op!=TK_COLUMN ){
+ if( pSubst->isOuterJoin && pCopy->op!=TK_COLUMN ){
memset(&ifNullRow, 0, sizeof(ifNullRow));
ifNullRow.op = TK_IF_NULL_ROW;
ifNullRow.pLeft = pCopy;
sqlite3ExprDelete(db, pNew);
return pExpr;
}
- if( pSubst->isLeftJoin ){
+ if( pSubst->isOuterJoin ){
ExprSetProperty(pNew, EP_CanBeNull);
}
if( ExprHasProperty(pExpr,EP_FromJoin|EP_InnerJoin) ){
SrcList *pSubSrc; /* The FROM clause of the subquery */
int iParent; /* VDBE cursor number of the pSub result set temp table */
int iNewParent = -1;/* Replacement table for iParent */
- int isLeftJoin = 0; /* True if pSub is the right side of a LEFT JOIN */
+ int isOuterJoin = 0; /* True if pSub is the right side of a LEFT JOIN */
int i; /* Loop counter */
Expr *pWhere; /* The WHERE clause */
SrcItem *pSubitem; /* The subquery */
**
** See also tickets #306, #350, and #3300.
*/
- if( (pSubitem->fg.jointype & JT_OUTER)!=0 ){
+ if( (pSubitem->fg.jointype & (JT_OUTER|JT_LTORJ))!=0 ){
if( pSubSrc->nSrc>1 /* (3a) */
|| isAgg /* (3b) */
|| IsVirtual(pSubSrc->a[0].pTab) /* (3c) */
){
return 0;
}
- isLeftJoin = 1;
+ isOuterJoin = 1;
}
#ifdef SQLITE_EXTRA_IFNULLROW
else if( iFrom>0 && !isAgg ){
- /* Setting isLeftJoin to -1 causes OP_IfNullRow opcodes to be generated for
+ /* Setting isOuterJoin to -1 causes OP_IfNullRow opcodes to be generated for
** every reference to any result column from subquery in a join, even
** though they are not necessary. This will stress-test the OP_IfNullRow
** opcode. */
- isLeftJoin = -1;
+ isOuterJoin = -1;
}
#endif
if( pSub->pOrderBy ){
return 0; /* Restriction (20) */
}
- if( isAgg || (p->selFlags & SF_Distinct)!=0 || isLeftJoin>0 ){
+ if( isAgg || (p->selFlags & SF_Distinct)!=0 || isOuterJoin>0 ){
return 0; /* (17d1), (17d2), or (17f) */
}
for(pSub1=pSub; pSub1; pSub1=pSub1->pPrior){
}
pWhere = pSub->pWhere;
pSub->pWhere = 0;
- if( isLeftJoin>0 ){
+ if( isOuterJoin>0 ){
sqlite3SetJoinExpr(pWhere, iNewParent, EP_FromJoin);
}
if( pWhere ){
x.pParse = pParse;
x.iTable = iParent;
x.iNewTable = iNewParent;
- x.isLeftJoin = isLeftJoin;
+ x.isOuterJoin = isOuterJoin;
x.pEList = pSub->pEList;
substSelect(&x, pParent, 0);
}
x.pParse = pParse;
x.iTable = iCursor;
x.iNewTable = iCursor;
- x.isLeftJoin = 0;
+ x.isOuterJoin = 0;
x.pEList = pSubq->pEList;
pNew = substExpr(&x, pNew);
#ifndef SQLITE_OMIT_WINDOWFUNC
projects / thirdparty / sqlite.git / commitdiff
