Add the TK_IF_NULL_ROW opcode to deal with non-NULL result columns in the

result set of a view or subquery on the RHS of a LEFT JOIN that gets flattened.

FossilOrigin-Name: 3a5860d86fadcf924316707918bf283d26c53b1473e5e67f5cff59d18c2a7742

diff --git a/manifest b/manifest
index a7b73eecdf358458fbda52165c2f438de5c64fc0..155f797a319f4d45c1dc2311b789d74fb4b24e95 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C An\sinitial\sattempt\sto\soptimize\sVIEWs\sthat\soccur\sas\sthe\sright\soperand\sof\sa\nLEFT\sJOIN.\s\sThis\sparticular\scheck-in\sdoes\snot\swork\scorrectly\sbecause\sit\sdoes\nnot\sdeal\swith\sthe\scase\sof\scolumns\sin\sthe\sVIEW\sthat\sreturn\snon-NULL\seven\swhen\nall\scolumns\sin\sthe\stable\sof\sthe\sVIEW\sare\sNULL\sbecause\sof\sthe\sLEFT\sJOIN.
-D 2017-04-14T17:18:45.647
+C Add\sthe\sTK_IF_NULL_ROW\sopcode\sto\sdeal\swith\snon-NULL\sresult\scolumns\sin\sthe\nresult\sset\sof\sa\sview\sor\ssubquery\son\sthe\sRHS\sof\sa\sLEFT\sJOIN\sthat\sgets\sflattened.
+D 2017-04-14T19:03:10.224
 F Makefile.in 1cc758ce3374a32425e4d130c2fe7b026b20de5b8843243de75f087c0a2661fb
 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 F Makefile.msc 6a8c838220f7c00820e1fc0ac1bccaaa8e5676067e1dbfa1bafa7a4ffecf8ae6
@@ -354,7 +354,7 @@ F src/ctime.c 47d91a25ad8f199a71a5b1b7b169d6dd0d6e98c5719eca801568798743d1161c
 F src/date.c ee676e7694dfadbdd2fde1a258a71be8360ba5ae
 F src/dbstat.c 19ee7a4e89979d4df8e44cfac7a8f905ec89b77d
 F src/delete.c 0d9d5549d42e79ce4d82ff1db1e6c81e36d2f67c
-F src/expr.c f6914d6d06c9a1e488f49cd51a0ef12d8073231e9c1a25c4c821262686cadcbf
+F src/expr.c f10e35dc50be4c8f82eb99bf5d8530229d1d60957cc3c9473ffe584d0444087c
 F src/fault.c 460f3e55994363812d9d60844b2a6de88826e007
 F src/fkey.c db65492ae549c3b548c9ef1f279ce1684f1c473b116e1c56a90878cd5dcf968d
 F src/func.c 9d52522cc8ae7f5cdadfe14594262f1618bc1f86083c4cd6da861b4cf5af6174
@@ -390,7 +390,7 @@ F src/os_win.c 2a6c73eef01c51a048cc4ddccd57f981afbec18a
 F src/os_win.h 7b073010f1451abe501be30d12f6bc599824944a
 F src/pager.c ff1232b3088a39806035ecfac4fffeb22717d80b
 F src/pager.h f2a99646c5533ffe11afa43e9e0bea74054e4efa
-F src/parse.y 48b03113704ee8bd78ee6996d81de7fbee22e105
+F src/parse.y 0513387ce02fea97897d8caef82d45f347818593f24f1bdc48e0c530a8af122d
 F src/pcache.c 62835bed959e2914edd26afadfecce29ece0e870
 F src/pcache.h 2cedcd8407eb23017d92790b112186886e179490
 F src/pcache1.c 1195a21fe28e223e024f900b2011e80df53793f0356a24caace4188b098540dc
@@ -401,7 +401,7 @@ F src/printf.c 8757834f1b54dae512fb25eb1acc8e94a0d15dd2290b58f2563f65973265adb2
 F src/random.c 80f5d666f23feb3e6665a6ce04c7197212a88384
 F src/resolve.c 3e518b962d932a997fae373366880fc028c75706
 F src/rowset.c 7b7e7e479212e65b723bf40128c7b36dc5afdfac
-F src/select.c 52b29bdeaa4cf317a981b6e8d0a15ec9c16372a738ede51c2a285c03fc69d036
+F src/select.c bf8ab605e49717c222136380453cfb7eda564f8e500d5ff6a01341ea59fefe80
 F src/shell.c 70f4957b988572315e97c56941fdc81fd35907fee36b7b2e7be5ec4c7e9d065d
 F src/sqlite.h.in 40233103e3e4e10f8a63523498d0259d232e42aba478e2d3fb914799185aced6
 F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
@@ -462,13 +462,13 @@ F src/test_windirent.h 5d67483a55442e31e1bde0f4a230e6e932ad5906
 F src/test_wsd.c 41cadfd9d97fe8e3e4e44f61a4a8ccd6f7ca8fe9
 F src/threads.c 4ae07fa022a3dc7c5beb373cf744a85d3c5c6c3c
 F src/tokenize.c 1003d6d90c6783206c711f0a9397656fa5b055209f4d092caa43bb3bf5215db5
-F src/treeview.c b92d57c1ac59f4a3f6b189506921a2b48098f6f4d6afd0b715bc2815ef6af092
+F src/treeview.c 6cf8d7fe9e63fae57dad1bb57f6615e14eac0c527e43d868e805042cae8ed1f7
 F src/trigger.c c9f0810043b265724fdb1bdd466894f984dfc182
 F src/update.c c443935c652af9365e033f756550b5032d02e1b06eb2cb890ed7511ae0c051dc
 F src/utf.c 699001c79f28e48e9bcdf8a463da029ea660540c
 F src/util.c ca8440ede81e155d15cff7c101654f60b55a9ae6
 F src/vacuum.c 1fe4555cd8c9b263afb85b5b4ee3a4a4181ad569
-F src/vdbe.c 808fda3d50f544120d27c731449b524b4ec8f8b0f734b228831078f0ba53ecb9
+F src/vdbe.c ef0fd44a2b4f70e006d050a98c6f563e19293d683975a95287668340764f99f1
 F src/vdbe.h f7d1456e28875c2dcb964056589b5b7149ab7edf39edeca801596a39bb3d3848
 F src/vdbeInt.h c070bc5c8b913bda0ceaa995cd4d939ded5e4fc96cf7c3c1c602d41b871f8ade
 F src/vdbeapi.c 5b08d82592bcff4470601fe78aaabebd50837860
@@ -482,7 +482,7 @@ F src/vxworks.h d2988f4e5a61a4dfe82c6524dd3d6e4f2ce3cdb9
 F src/wal.c 40c543f0a2195d1b0dc88ef12142bea690009344
 F src/wal.h 06b2a0b599cc0f53ea97f497cf8c6b758c999f71
 F src/walker.c b71a992b413b3a022572eccf29ef4b4890223791
-F src/where.c 1d14e18f32231fa7969e718e7b60ef749b0065e2a7e1b6b00883b20732d280f1
+F src/where.c e02cbd8a830d36e48b1640d0c7b49526322e35fa800c729c17c5d63712a01275
 F src/whereInt.h 7a21ef633e26acbf46df04add2eba6e0a2100c78dc5879049e93f981fc3344df
 F src/wherecode.c 943e32e9dccd0af802e0683ae11071c8bd808364e5908a5fb66758bd404c8681
 F src/whereexpr.c e913aaa7b73ffcce66abcea5f197e2c538d48b5df78d0b7bba8ff4d73cc2e745
@@ -1483,7 +1483,7 @@ F test/zerodamage.test e59a56443d6298ecf7435f618f0b27654f0c849e
 F tool/GetFile.cs a15e08acb5dd7539b75ba23501581d7c2b462cb5
 F tool/GetTclKit.bat 6afa640edc7810725aec61c3076ac617c4aaf0b7
 F tool/Replace.cs 02c67258801c2fb5f63231e0ac0f220b4b36ba91
-F tool/addopcodes.tcl 10c889c4a65ec6c5604e4a47306fa77ff57ae189
+F tool/addopcodes.tcl edbd53806bf20e25af2373ad0c091be4385081c1aa1813b916bf093f94ed8380
 F tool/build-all-msvc.bat c12328d06c45fec8baada5949e3d5af54bf8c887 x
 F tool/build-shell.sh 950f47c6174f1eea171319438b93ba67ff5bf367
 F tool/cg_anno.tcl f95b0006c52cf7f0496b506343415b6ee3cdcdd3 x
@@ -1571,10 +1571,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 6bf673767b8e5cedef1acff795cbe524fab8db2525c06424db4e038934a33936
-R 8dfa3ca7454fc6936bedb04ccf47ee12
-T *branch * left-join-view
-T *sym-left-join-view *
-T -sym-trunk *
+P 1838a59c8a1c151bd6fc822b0ffef661803cf0e4704c917e74a04567b81740b9
+R c4158b7e84d910d8bf443bd31845d425
 U drh
-Z 5ef873863ca7134987a034a627c04882
+Z 30ed19e82c986c3025ce3aa1a6102ed4

diff --git a/manifest.uuid b/manifest.uuid
index f881b041a7eeeb052a999971344710e61126c565..bf413e2eb0b68d82e5a1ba2675d626b302628846 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-1838a59c8a1c151bd6fc822b0ffef661803cf0e4704c917e74a04567b81740b9
\ No newline at end of file
+3a5860d86fadcf924316707918bf283d26c53b1473e5e67f5cff59d18c2a7742
\ No newline at end of file

diff --git a/src/expr.c b/src/expr.c
index ad17c5f22933cb133773cbfc39fff938d9997427..873911633fdcade01bb82105cdd0a6b295ae546c 100644 (file)
--- a/src/expr.c
+++ b/src/expr.c
@@ -3889,6 +3889,17 @@ int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){
       break;
     }
 
+    case TK_IF_NULL_ROW: {
+      int addrINR;
+      addrINR = sqlite3VdbeAddOp1(v, OP_IfNullRow, pExpr->iTable);
+      sqlite3ExprCachePush(pParse);
+      inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);
+      sqlite3ExprCachePop(pParse);
+      sqlite3VdbeJumpHere(v, addrINR);
+      sqlite3VdbeChangeP3(v, addrINR, inReg);
+      break;
+    }
+
     /*
     ** Form A:
     **   CASE x WHEN e1 THEN r1 WHEN e2 THEN r2 ... WHEN eN THEN rN ELSE y END

diff --git a/src/parse.y b/src/parse.y
index ef9d3dd0ecb0f04cea18dea95206196b426497a2..522c80548255f1b19913c50049ea3e8dfc576d00 100644 (file)
--- a/src/parse.y
+++ b/src/parse.y
@@ -193,6 +193,23 @@ columnlist ::= columnlist COMMA columnname carglist.
 columnlist ::= columnname carglist.
 columnname(A) ::= nm(A) typetoken(Y). {sqlite3AddColumn(pParse,&A,&Y);}
 
+// The following directive causes tokens ABORT, AFTER, ASC, etc. to
+// fallback to ID if they will not parse as their original value.
+// This obviates the need for the "id" nonterminal.
+//
+%fallback ID
+  ABORT ACTION AFTER ANALYZE ASC ATTACH BEFORE BEGIN BY CASCADE CAST COLUMNKW
+  CONFLICT DATABASE DEFERRED DESC DETACH EACH END EXCLUSIVE EXPLAIN FAIL FOR
+  IGNORE IMMEDIATE INITIALLY INSTEAD LIKE_KW MATCH NO PLAN
+  QUERY KEY OF OFFSET PRAGMA RAISE RECURSIVE RELEASE REPLACE RESTRICT ROW
+  ROLLBACK SAVEPOINT TEMP TRIGGER VACUUM VIEW VIRTUAL WITH WITHOUT
+%ifdef SQLITE_OMIT_COMPOUND_SELECT
+  EXCEPT INTERSECT UNION
+%endif SQLITE_OMIT_COMPOUND_SELECT
+  REINDEX RENAME CTIME_KW IF
+  .
+%wildcard ANY.
+
 // Define operator precedence early so that this is the first occurrence
 // of the operator tokens in the grammer.  Keeping the operators together
 // causes them to be assigned integer values that are close together,
@@ -222,23 +239,6 @@ columnname(A) ::= nm(A) typetoken(Y). {sqlite3AddColumn(pParse,&A,&Y);}
 //
 %token_class id  ID|INDEXED.
 
-// The following directive causes tokens ABORT, AFTER, ASC, etc. to
-// fallback to ID if they will not parse as their original value.
-// This obviates the need for the "id" nonterminal.
-//
-%fallback ID
-  ABORT ACTION AFTER ANALYZE ASC ATTACH BEFORE BEGIN BY CASCADE CAST COLUMNKW
-  CONFLICT DATABASE DEFERRED DESC DETACH EACH END EXCLUSIVE EXPLAIN FAIL FOR
-  IGNORE IMMEDIATE INITIALLY INSTEAD LIKE_KW MATCH NO PLAN
-  QUERY KEY OF OFFSET PRAGMA RAISE RECURSIVE RELEASE REPLACE RESTRICT ROW
-  ROLLBACK SAVEPOINT TEMP TRIGGER VACUUM VIEW VIRTUAL WITH WITHOUT
-%ifdef SQLITE_OMIT_COMPOUND_SELECT
-  EXCEPT INTERSECT UNION
-%endif SQLITE_OMIT_COMPOUND_SELECT
-  REINDEX RENAME CTIME_KW IF
-  .
-%wildcard ANY.
-
 
 // And "ids" is an identifer-or-string.
 //

diff --git a/src/select.c b/src/select.c
index 8e952d5a8a079a769104e86caf7632c9e7009f69..3def13618e1a9016195cd6901e845eba1032ec98 100644 (file)
--- a/src/select.c
+++ b/src/select.c
@@ -3154,7 +3154,8 @@ static int multiSelectOrderBy(
 typedef struct SubstContext {
   Parse *pParse;            /* The parsing context */
   int iTable;               /* Replace references to this table */
-  int iNewTable;            /* New table number, or -1 */
+  int iNewTable;            /* New table number */
+  int isLeftJoin;           /* Add TK_IF_NULL_ROW opcodes on each replacement */
   ExprList *pEList;         /* Replacement expressions */
 } SubstContext;
 
@@ -3189,12 +3190,20 @@ static Expr *substExpr(
     }else{
       Expr *pNew;
       Expr *pCopy = pSubst->pEList->a[pExpr->iColumn].pExpr;
+      Expr ifNullRow;
       assert( pSubst->pEList!=0 && pExpr->iColumn<pSubst->pEList->nExpr );
       assert( pExpr->pLeft==0 && pExpr->pRight==0 );
       if( sqlite3ExprIsVector(pCopy) ){
         sqlite3VectorErrorMsg(pSubst->pParse, pCopy);
       }else{
         sqlite3 *db = pSubst->pParse->db;
+        if( pSubst->isLeftJoin && pCopy->op!=TK_COLUMN ){
+          memset(&ifNullRow, 0, sizeof(ifNullRow));
+          ifNullRow.op = TK_IF_NULL_ROW;
+          ifNullRow.pLeft = pCopy;
+          ifNullRow.iTable = pSubst->iNewTable;
+          pCopy = &ifNullRow;
+        }
         pNew = sqlite3ExprDup(db, pCopy, 0);
         if( pNew && (pExpr->flags & EP_FromJoin) ){
           pNew->iRightJoinTable = pExpr->iRightJoinTable;
@@ -3288,14 +3297,8 @@ static void substSelect(
 **        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
-**        or (3b) the subquery is not a join and (3c) does not contain any
-**        result-set columns that could be non-NULL even if columns of the
-**        subquery table are NULL.
-**        to be more restrictive - disallowing subquery if it was the
-**        right operand of a left join.  See tickets #306 and #3300. Relaxed
-**        to allow simple subqueries as the right operand of a left join
-**        on 2017-04-14.)
+**   (3)  The subquery is not the right operand of a LEFT JOIN
+**        or the subquery is not itself a join.
 **
 **   (4)  The subquery is not DISTINCT.
 **
@@ -3307,7 +3310,7 @@ static void substSelect(
 **        DISTINCT.
 **
 **   (7)  The subquery has a FROM clause.  TODO:  For subqueries without
-**        A FROM clause, consider adding a FROM close with the special
+**        A FROM clause, consider adding a FROM clause with the special
 **        table sqlite_once that consists of a single row containing a
 **        single NULL.
 **
@@ -3491,15 +3494,13 @@ static int flattenSubquery(
   **
   ** which is not at all the same thing.
   **
-  ** See also tickets #306 and #3300.
+  ** See also tickets #306, #350, and #3300.
   */
   if( (pSubitem->fg.jointype & JT_OUTER)!=0 ){
     isLeftJoin = 1;
     if( pSubSrc->nSrc>1 ){
-      return 0; /* Restriction (3b) */
+      return 0; /* Restriction (3) */
     }
-    /* TBD: Deal with the case of result-set expressions that are non-NULL even
-    ** when the RHS table of a LEFT JOIN is NULL. */
   }
 
   /* Restriction 17: If the sub-query is a compound SELECT, then it must
@@ -3774,6 +3775,7 @@ static int flattenSubquery(
       x.pParse = pParse;
       x.iTable = iParent;
       x.iNewTable = iNewParent;
+      x.isLeftJoin = isLeftJoin;
       x.pEList = pSub->pEList;
       substSelect(&x, pParent, 0);
     }
@@ -3883,6 +3885,7 @@ static int pushDownWhereTerms(
       x.pParse = pParse;
       x.iTable = iCursor;
       x.iNewTable = iCursor;
+      x.isLeftJoin = 0;
       x.pEList = pSubq->pEList;
       pNew = substExpr(&x, pNew);
       pSubq->pWhere = sqlite3ExprAnd(pParse->db, pSubq->pWhere, pNew);

diff --git a/src/treeview.c b/src/treeview.c
index e4f3d781ba3ce0640f2e97bacd45315dbaa4bdf5..fc188256f9719fbcc0298f14504bcc1b7c876c1d 100644 (file)
--- a/src/treeview.c
+++ b/src/treeview.c
@@ -470,6 +470,11 @@ void sqlite3TreeViewExpr(TreeView *pView, const Expr *pExpr, u8 moreToFollow){
       sqlite3TreeViewSelect(pView, pExpr->pLeft->x.pSelect, 0);
       break;
     }
+    case TK_IF_NULL_ROW: {
+      sqlite3TreeViewLine(pView, "IF-NULL-ROW %d", pExpr->iTable);
+      sqlite3TreeViewExpr(pView, pExpr->pLeft, 0);
+      break;
+    }
     default: {
       sqlite3TreeViewLine(pView, "op=%d", pExpr->op);
       break;

diff --git a/src/vdbe.c b/src/vdbe.c
index a990afb11d148b6657401923f19d49b991729bad..cd3d08a1404a17bd9dd51d008eee61aadf557e57 100644 (file)
--- a/src/vdbe.c
+++ b/src/vdbe.c
@@ -2429,6 +2429,23 @@ case OP_NotNull: {            /* same as TK_NOTNULL, jump, in1 */
   break;
 }
 
+/* Opcode: IfNullRow P1 P2 P3 * *
+** Synopsis: if P1.nullRow then r[P3]=NULL, goto P2
+**
+** Check the cursor P1 to see if it is currently pointing at a NULL row.
+** If it is, then set register P3 to NULL and jump immediately to P2.
+** If P1 is not on a NULL row, then fall through without making any
+** changes.
+*/
+case OP_IfNullRow: {         /* jump */
+  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
+  if( p->apCsr[pOp->p1]->nullRow ){
+    sqlite3VdbeMemSetNull(aMem + pOp->p3);
+    goto jump_to_p2;
+  }
+  break;
+}
+
 /* Opcode: Column P1 P2 P3 P4 P5
 ** Synopsis: r[P3]=PX
 **

diff --git a/src/where.c b/src/where.c
index 38183d6849008bb01c4e2578e3ebff93f1cfbcc6..5c5652f05846d9b63a21d1ad3cde469c48ba099c 100644 (file)
--- a/src/where.c
+++ b/src/where.c
@@ -4976,6 +4976,8 @@ void sqlite3WhereEnd(WhereInfo *pWInfo){
         }else if( pOp->opcode==OP_Rowid ){
           pOp->p1 = pLevel->iIdxCur;
           pOp->opcode = OP_IdxRowid;
+        }else if( pOp->opcode==OP_IfNullRow ){
+          pOp->p1 = pLevel->iIdxCur;
         }
       }
     }

diff --git a/tool/addopcodes.tcl b/tool/addopcodes.tcl
index a6c58f1a251c83cff9bc343dd1fce681cb17fce5..308ddcb6bdc83ccafa2e4f29316c36c8088bfefb 100644 (file)
--- a/tool/addopcodes.tcl
+++ b/tool/addopcodes.tcl
@@ -39,6 +39,7 @@ set extras {
   REGISTER
   VECTOR
   SELECT_COLUMN
+  IF_NULL_ROW
   ASTERISK
   SPAN
   SPACE