Restrain the flattener in the presence of outer joins. Ticket #306. (CVS 958)

FossilOrigin-Name: 6d4b6597e560578253960d9876dc8c8657f41fef

manifest

@@ -1,5 +1,5 @@
-C Added\stests\strying\s(unsuccessfully)\sto\sreproduce\sticket\s#304.\s(CVS\s957)
-D 2003-05-04T20:42:56
+C Restrain\sthe\sflattener\sin\sthe\spresence\sof\souter\sjoins.\s\sTicket\s#306.\s(CVS\s958)
+D 2003-05-06T20:35:16
 F Makefile.in 004acec253ecdde985c8ecd5b7c9accdb210378f
 F Makefile.linux-gcc b86a99c493a5bfb402d1d9178dcdc4bd4b32f906
 F README f1de682fbbd94899d50aca13d387d1b3fd3be2dd
@@ -43,7 +43,7 @@ F src/parse.y 39b5240cb78047dc56d6d37c398baed7ba556779
 F src/pragma.c 118fe400d71b7fdcc03580d5eab6bb5aa00772a5
 F src/printf.c fc5fdef6e92ad205005263661fe9716f55a49f3e
 F src/random.c 19e8e00fe0df32a742f115773f57651be327cabe
-F src/select.c 3fe63e3a29df661ba72a67eecd77e8ee82801def
+F src/select.c c06b4605bca03d8237a3fc4098179bf3a7133702
 F src/shell.c 89a14538b40fbfa15b0ad10b3367aab272bd9f15
 F src/shell.tcl 27ecbd63dd88396ad16d81ab44f73e6c0ea9d20e
 F src/sqlite.h.in eec06462cba262c0ee03f38462a18a4bc66dda4e
@@ -87,7 +87,7 @@ F test/insert.test 5697ba098e4d8a6f0151f281b7e39dec9c439e05
 F test/insert2.test c288375a64dad3295044714f0dfed4a193cf067f
 F test/intpkey.test 39f49fd993350f7f3ab255e5cfbf9a09d8f8800e
 F test/ioerr.test 5dbaf09f96b56ee01cf3edd762b96eb4ad2c9ca4
-F test/join.test c97267c19294bf1fa4e81087edad179828bced88
+F test/join.test 16c91ec27170c20e2a10796775e62c5c3dcbda44
 F test/limit.test 9ffb965a0f5bf7152187ef3d8d1249b96e5620bf
 F test/lock.test 388a3a10962d2d571c0c1821cc35bf069ee73473
 F test/main.test 6a851b5992c4881a725a3d9647e629199df8de9d
@@ -165,7 +165,7 @@ F www/speed.tcl cb4c10a722614aea76d2c51f32ee43400d5951be
 F www/sqlite.tcl ffde644361e1d8e2a44a235ff23ad3b43d640df2
 F www/tclsqlite.tcl 1db15abeb446aad0caf0b95b8b9579720e4ea331
 F www/vdbe.tcl 2013852c27a02a091d39a766bc87cff329f21218
-P 5656fe48b192dc84cb5977f826ff99d81684791f
-R cdec87c4eaf662069dea6dbf74494ed5
+P fda637f453d35b74f676997fcf056a948ccd771b
+R ce92f17887cce1b923da966e242b319f
 U drh
-Z 054b394f2a79b867a0d598db2de3f85c
+Z ab57ff50799dad75d8d41943b87540c0

manifest.uuid

@@ -1 +1 @@
-fda637f453d35b74f676997fcf056a948ccd771b
+6d4b6597e560578253960d9876dc8c8657f41fef

src/select.c

@@ -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 1.137 2003/05/02 16:04:17 drh Exp $
+** $Id: select.c,v 1.138 2003/05/06 20:35:16 drh Exp $
 */
 #include "sqliteInt.h"
 
@@ -1555,7 +1555,8 @@ substExprList(ExprList *pList, int iTable, ExprList *pEList){
 **
 **   (2)  The subquery is not an aggregate or the outer query is not a join.
 **
-**   (3)  (No longer a restriction)
+**   (3)  The subquery is not the right operand of a left outer join, or
+**        the subquery is not itself a join.  (Ticket #306)
 **
 **   (4)  The subquery is not DISTINCT or the outer query is not a join.
 **
@@ -1620,6 +1621,22 @@ static int flattenSubquery(
   if( (p->isDistinct || p->nLimit>=0) && subqueryIsAgg ) return 0;
   if( p->pOrderBy && pSub->pOrderBy ) return 0;
 
+  /* Restriction 3:  If the subquery is a join, make sure the subquery is 
+  ** not used as the right operand of an outer join.  Examples of why this
+  ** is not allowed:
+  **
+  **         t1 LEFT OUTER JOIN (t2 JOIN t3)
+  **
+  ** If we flatten the above, we would get
+  **
+  **         (t1 LEFT OUTER JOIN t2) JOIN t3
+  **
+  ** which is not at all the same thing.
+  */
+  if( pSubSrc->nSrc>1 && iFrom>0 && (pSrc->a[iFrom-1].jointype & JT_OUTER)!=0 ){
+    return 0;
+  }
+
   /* If we reach this point, it means flattening is permitted for the
   ** iFrom-th entry of the FROM clause in the outer query.
   */
@@ -1635,6 +1652,7 @@ static int flattenSubquery(
   iParent = pSrc->a[iFrom].iCursor;
   {
     int nSubSrc = pSubSrc->nSrc;
+    int jointype = pSrc->a[iFrom].jointype;
 
     if( pSrc->a[iFrom].pTab && pSrc->a[iFrom].pTab->isTransient ){
       sqliteDeleteTable(0, pSrc->a[iFrom].pTab);
@@ -1655,6 +1673,7 @@ static int flattenSubquery(
       pSrc->a[i+iFrom] = pSubSrc->a[i];
       memset(&pSubSrc->a[i], 0, sizeof(pSubSrc->a[i]));
     }
+    pSrc->a[iFrom+nSubSrc-1].jointype = jointype;
   }
 
   /* Now begin substituting subquery result set expressions for 

test/join.test

@@ -12,7 +12,7 @@
 #
 # This file implements tests for joins, including outer joins.
 #
-# $Id: join.test,v 1.8 2003/02/20 01:48:13 drh Exp $
+# $Id: join.test,v 1.9 2003/05/06 20:35:17 drh Exp $
 
 set testdir [file dirname $argv0]
 source $testdir/tester.tcl
@@ -377,4 +377,30 @@ do_test join-7.1 {
   }
 } {1 999 999 2 131 130 999}
 
+# Make sure a left join where the right table is really a view that
+# is itself a join works right.  Ticket #306.
+#
+do_test join-8.1 {
+  execsql {
+    BEGIN;
+    CREATE TABLE t9(a INTEGER PRIMARY KEY, b);
+    INSERT INTO t9 VALUES(1,11);
+    INSERT INTO t9 VALUES(2,22);
+    CREATE TABLE t10(x INTEGER PRIMARY KEY, y);
+    INSERT INTO t10 VALUES(1,2);
+    INSERT INTO t10 VALUES(3,3);    
+    CREATE TABLE t11(p INTEGER PRIMARY KEY, q);
+    INSERT INTO t11 VALUES(2,111);
+    INSERT INTO t11 VALUES(3,333);    
+    CREATE VIEW v10_11 AS SELECT x, q FROM t10, t11 WHERE t10.y=t11.p;
+    COMMIT;
+    SELECT * FROM t9 LEFT JOIN v10_11 ON( a=x );
+  }
+} {1 11 1 111 2 22 {} {}}
+do_test join-8.2 {
+  execsql {
+    SELECT * FROM v10_11 LEFT JOIN t9 ON( a=x );
+  }
+} {1 111 1 11 3 333 {} {}}
+
 finish_test