Do not flatten aggregate subqueries that contain min() or max() functions

so that if the min()/max() are discarded by the outer query, they still
function and cause non-aggregate expression to be evaluated on the minimal
or maximal row.

FossilOrigin-Name: 0bdf1a086b3946722f4d4b328e25917f61c14713

manifest

@@ -1,5 +1,5 @@
-C Adjust\scomments\sto\sshow\sthat\ssubquery\sflattening\srestriction\s(10)\swas\nremoved\sfrom\sthe\scode\sback\sin\s2005.\s\sThis\sis\sa\scomment\schange\sonly.
+C Do\snot\sflatten\saggregate\ssubqueries\sthat\scontain\smin()\sor\smax()\sfunctions\nso\sthat\sif\sthe\smin()/max()\sare\sdiscarded\sby\sthe\souter\squery,\sthey\sstill\nfunction\sand\scause\snon-aggregate\sexpression\sto\sbe\sevaluated\son\sthe\sminimal\nor\smaximal\srow.
-D 2014-09-15T11:14:50.871
+D 2014-09-15T14:46:02.082
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in cf57f673d77606ab0f2d9627ca52a9ba1464146a
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -183,7 +183,7 @@ F src/delete.c fae81cc2eb14b75267d4f47d3cfc9ae02aae726f
 F src/expr.c 19392d98e089640c3336e65b4254cc337efef7d1
 F src/fault.c 160a0c015b6c2629d3899ed2daf63d75754a32bb
 F src/fkey.c da985ae673efef2c712caef825a5d2edb087ead7
-F src/func.c d4d218704b13bc1814b7d76874e405743c903773
+F src/func.c 5d498933f6168dff80941c873805fe04dc2b766d
 F src/global.c 5110fa12e09729b84eee0191c984ec4008e21937
 F src/hash.c 4263fbc955f26c2e8cdc0cf214bc42435aa4e4f5
 F src/hash.h c8f3c31722cf3277d03713909761e152a5b81094
@@ -224,14 +224,14 @@ F src/pragma.c 3f3e959390a10c0131676f0e307acce372777e0f
 F src/prepare.c 6ef0cf2f9274982988ed6b7cab1be23147e94196
 F src/printf.c e74925089a85e3c9f0e315595f41c139d3d118c2
 F src/random.c d10c1f85b6709ca97278428fd5db5bbb9c74eece
-F src/resolve.c 0d1621e45fffe4b4396477cf46e41a84b0145ffb
+F src/resolve.c a3466128b52a86c466e47ac1a19e2174f7b5cf89
 F src/rowset.c eccf6af6d620aaa4579bd3b72c1b6395d9e9fa1e
-F src/select.c 70312b18bf56f741556ed494c398afa0ca3c0e1a
+F src/select.c 0cd6706fd52ae5db229e9041094db6ec27195335
 F src/shell.c c00220cdd7f2027780bc25b78376c16dc24e4b7d
 F src/sqlite.h.in 8b018219ce988913e5977d5de9ab4beb33be23b6
 F src/sqlite3.rc 992c9f5fb8285ae285d6be28240a7e8d3a7f2bad
 F src/sqlite3ext.h 17d487c3c91b0b8c584a32fbeb393f6f795eea7d
-F src/sqliteInt.h e9030816d5ee6fe2063553b40359096f994664ee
+F src/sqliteInt.h 0803e900eb1882f7dd88e86ddcddd2d1b27c8d86
 F src/sqliteLimit.h 164b0e6749d31e0daa1a4589a169d31c0dec7b3d
 F src/status.c 7ac05a5c7017d0b9f0b4bcd701228b784f987158
 F src/table.c 218ae2ba022881846741dfc8351aefdf129e0377
@@ -305,7 +305,7 @@ F src/where.c 839b5e1db2507e221ad1c308f148a8519ed750be
 F src/whereInt.h 124d970450955a6982e174b07c320ae6d62a595c
 F test/8_3_names.test ebbb5cd36741350040fd28b432ceadf495be25b2
 F test/aggerror.test a867e273ef9e3d7919f03ef4f0e8c0d2767944f2
-F test/aggnested.test 45c0201e28045ad38a530b5a144b73cd4aa2cfd6
+F test/aggnested.test b35b4cd69fc913f90d39a575e171e1116c3a4bb7
 F test/alias.test 4529fbc152f190268a15f9384a5651bbbabc9d87
 F test/all.test 6ff7b43c2b4b905c74dc4a813d201d0fa64c5783
 F test/alter.test 547dc2d292644301ac9a7dda22b319b74f9c08d2
@@ -712,7 +712,7 @@ F test/memsubsys2.test 3a1c1a9de48e5726faa85108b02459fae8cb9ee9
 F test/minmax.test 42fbad0e81afaa6e0de41c960329f2b2c3526efd
 F test/minmax2.test b44bae787fc7b227597b01b0ca5575c7cb54d3bc
 F test/minmax3.test cc1e8b010136db0d01a6f2a29ba5a9f321034354
-F test/minmax4.test 536a3360470633a177e42fbc19660d146b51daef
+F test/minmax4.test 936941484ebdceb8adec7c86b6cd9b6e5e897c1f
 F test/misc1.test 1201a037c24f982cc0e956cdaa34fcaf6439c417
 F test/misc2.test 00d7de54eda90e237fc9a38b9e5ccc769ebf6d4d
 F test/misc3.test cf3dda47d5dda3e53fc5804a100d3c82be736c9d
@@ -1197,7 +1197,7 @@ F tool/vdbe_profile.tcl 67746953071a9f8f2f668b73fe899074e2c6d8c1
 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh 0abfd78ceb09b7f7c27c688c8e3fe93268a13b32
 F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
-P b332a84d5154f70f3197537df4af243eaebbb011
+P 4ff0eb96bc364baed2d8005c69291ca9240b99dd
-R 4fde0e674c64eada90bf3beabe45d5b4
+R d83c0c27bf862a8b9f30cb2ccec5fde3
 U drh
-Z 7e796116236157f7f97effb3ae76fb8a
+Z 5049f8c8dea35bd8f91ea699f6fd9960

manifest.uuid

@@ -1 +1 @@
-4ff0eb96bc364baed2d8005c69291ca9240b99dd
+0bdf1a086b3946722f4d4b328e25917f61c14713

src/func.c

@@ -1663,10 +1663,12 @@ void sqlite3RegisterGlobalFunctions(void){
     FUNCTION(trim,               2, 3, 0, trimFunc         ),
     FUNCTION(min,               -1, 0, 1, minmaxFunc       ),
     FUNCTION(min,                0, 0, 1, 0                ),
-    AGGREGATE(min,               1, 0, 1, minmaxStep,      minMaxFinalize ),
+    AGGREGATE2(min,              1, 0, 1, minmaxStep,      minMaxFinalize,
+                                          SQLITE_FUNC_MINMAX ),
     FUNCTION(max,               -1, 1, 1, minmaxFunc       ),
     FUNCTION(max,                0, 1, 1, 0                ),
-    AGGREGATE(max,               1, 1, 1, minmaxStep,      minMaxFinalize ),
+    AGGREGATE2(max,              1, 1, 1, minmaxStep,      minMaxFinalize,
+                                          SQLITE_FUNC_MINMAX ),
     FUNCTION2(typeof,            1, 0, 0, typeofFunc,  SQLITE_FUNC_TYPEOF),
     FUNCTION2(length,            1, 0, 0, lengthFunc,  SQLITE_FUNC_LENGTH),
     FUNCTION(instr,              2, 0, 0, instrFunc        ),
@@ -1719,8 +1721,8 @@ void sqlite3RegisterGlobalFunctions(void){
     AGGREGATE(sum,               1, 0, 0, sumStep,         sumFinalize    ),
     AGGREGATE(total,             1, 0, 0, sumStep,         totalFinalize    ),
     AGGREGATE(avg,               1, 0, 0, sumStep,         avgFinalize    ),
- /* AGGREGATE(count,             0, 0, 0, countStep,       countFinalize  ), */
+    AGGREGATE2(count,            0, 0, 0, countStep,       countFinalize,
-    {0,SQLITE_UTF8|SQLITE_FUNC_COUNT,0,0,0,countStep,countFinalize,"count",0,0},
+               SQLITE_FUNC_COUNT  ),
     AGGREGATE(count,             1, 0, 0, countStep,       countFinalize  ),
     AGGREGATE(group_concat,      1, 0, 0, groupConcatStep, groupConcatFinalize),
     AGGREGATE(group_concat,      2, 0, 0, groupConcatStep, groupConcatFinalize),

src/resolve.c

@@ -719,9 +719,7 @@ static int resolveExprStep(Walker *pWalker, Expr *pExpr){
             pExpr->iTable = pDef->zName[0]=='u' ? 62 : 938;
           }             
         }
-      }
 #ifndef SQLITE_OMIT_AUTHORIZATION
-      if( pDef ){
         auth = sqlite3AuthCheck(pParse, SQLITE_FUNCTION, 0, pDef->zName, 0);
         if( auth!=SQLITE_OK ){
           if( auth==SQLITE_DENY ){
@@ -732,9 +730,9 @@ static int resolveExprStep(Walker *pWalker, Expr *pExpr){
           pExpr->op = TK_NULL;
           return WRC_Prune;
         }
+#endif
         if( pDef->funcFlags & SQLITE_FUNC_CONSTANT ) ExprSetProperty(pExpr,EP_Constant);
       }
-#endif
       if( is_agg && (pNC->ncFlags & NC_AllowAgg)==0 ){
         sqlite3ErrorMsg(pParse, "misuse of aggregate function %.*s()", nId,zId);
         pNC->nErr++;
@@ -757,7 +755,13 @@ static int resolveExprStep(Walker *pWalker, Expr *pExpr){
           pExpr->op2++;
           pNC2 = pNC2->pNext;
         }
-        if( pNC2 ) pNC2->ncFlags |= NC_HasAgg;
+        assert( pDef!=0 );
+        if( pNC2 ){
+          assert( SQLITE_FUNC_MINMAX==NC_MinMaxAgg );
+          testcase( (pDef->funcFlags & SQLITE_FUNC_MINMAX)!=0 );
+          pNC2->ncFlags |= NC_HasAgg | (pDef->funcFlags & SQLITE_FUNC_MINMAX);
+
+        }
         pNC->ncFlags |= NC_AllowAgg;
       }
       /* FIX ME:  Compute pExpr->affinity based on the expected return
@@ -1222,7 +1226,8 @@ static int resolveSelectStep(Walker *pWalker, Select *p){
     assert( (p->selFlags & SF_Aggregate)==0 );
     pGroupBy = p->pGroupBy;
     if( pGroupBy || (sNC.ncFlags & NC_HasAgg)!=0 ){
-      p->selFlags |= SF_Aggregate;
+      assert( NC_MinMaxAgg==SF_MinMaxAgg );
+      p->selFlags |= SF_Aggregate | (sNC.ncFlags&NC_MinMaxAgg);
     }else{
       sNC.ncFlags &= ~NC_AllowAgg;
     }
@@ -1350,7 +1355,7 @@ int sqlite3ResolveExprNames(
   NameContext *pNC,       /* Namespace to resolve expressions in. */
   Expr *pExpr             /* The expression to be analyzed. */
 ){
-  u8 savedHasAgg;
+  u16 savedHasAgg;
   Walker w;
 
   if( pExpr==0 ) return 0;
@@ -1363,8 +1368,8 @@ int sqlite3ResolveExprNames(
     pParse->nHeight += pExpr->nHeight;
   }
 #endif
-  savedHasAgg = pNC->ncFlags & NC_HasAgg;
+  savedHasAgg = pNC->ncFlags & (NC_HasAgg|NC_MinMaxAgg);
-  pNC->ncFlags &= ~NC_HasAgg;
+  pNC->ncFlags &= ~(NC_HasAgg|NC_MinMaxAgg);
   memset(&w, 0, sizeof(w));
   w.xExprCallback = resolveExprStep;
   w.xSelectCallback = resolveSelectStep;
@@ -1379,9 +1384,8 @@ int sqlite3ResolveExprNames(
   }
   if( pNC->ncFlags & NC_HasAgg ){
     ExprSetProperty(pExpr, EP_Agg);
-  }else if( savedHasAgg ){
-    pNC->ncFlags |= NC_HasAgg;
   }
+  pNC->ncFlags |= savedHasAgg;
   return ExprHasProperty(pExpr, EP_Error);
 }
 

src/select.c

@@ -3197,6 +3197,11 @@ static void substSelect(
 **        parent to a compound query confuses the code that handles
 **        recursive queries in multiSelect().
 **
+**  (24)  The subquery is not an aggregate that uses the built-in min() or 
+**        or max() functions.  (Without this restriction, a query like:
+**        "SELECT x FROM (SELECT max(y), x FROM t1)" would not necessarily
+**        return the value X for which Y was maximal.)
+**
 **
 ** 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
@@ -3269,8 +3274,14 @@ static int flattenSubquery(
   if( pSub->pLimit && (p->selFlags & SF_Distinct)!=0 ){
      return 0;         /* Restriction (21) */
   }
-  if( pSub->selFlags & SF_Recursive ) return 0;          /* Restriction (22)  */
+  testcase( pSub->selFlags & SF_Recursive );
-  if( (p->selFlags & SF_Recursive) && pSub->pPrior ) return 0;       /* (23)  */
+  testcase( pSub->selFlags & SF_MinMaxAgg );
+  if( pSub->selFlags & (SF_Recursive|SF_MinMaxAgg) ){
+    return 0; /* Restrictions (22) and (24) */
+  }
+  if( (p->selFlags & SF_Recursive) && pSub->pPrior ){
+    return 0; /* Restriction (23) */
+  }
 
   /* OBSOLETE COMMENT 1:
   ** Restriction 3:  If the subquery is a join, make sure the subquery is 

src/sqliteInt.h

@@ -1285,6 +1285,7 @@ struct FuncDestructor {
 #define SQLITE_FUNC_COALESCE 0x200 /* Built-in coalesce() or ifnull() */
 #define SQLITE_FUNC_UNLIKELY 0x400 /* Built-in unlikely() function */
 #define SQLITE_FUNC_CONSTANT 0x800 /* Constant inputs give a constant output */
+#define SQLITE_FUNC_MINMAX  0x1000 /* True for min() and max() aggregates */
 
 /*
 ** The following three macros, FUNCTION(), LIKEFUNC() and AGGREGATE() are
@@ -1332,6 +1333,9 @@ struct FuncDestructor {
 #define AGGREGATE(zName, nArg, arg, nc, xStep, xFinal) \
   {nArg, SQLITE_UTF8|(nc*SQLITE_FUNC_NEEDCOLL), \
    SQLITE_INT_TO_PTR(arg), 0, 0, xStep,xFinal,#zName,0,0}
+#define AGGREGATE2(zName, nArg, arg, nc, xStep, xFinal, extraFlags) \
+  {nArg, SQLITE_UTF8|(nc*SQLITE_FUNC_NEEDCOLL)|extraFlags, \
+   SQLITE_INT_TO_PTR(arg), 0, 0, xStep,xFinal,#zName,0,0}
 
 /*
 ** All current savepoints are stored in a linked list starting at
@@ -2254,17 +2258,22 @@ struct NameContext {
   NameContext *pNext;  /* Next outer name context.  NULL for outermost */
   int nRef;            /* Number of names resolved by this context */
   int nErr;            /* Number of errors encountered while resolving names */
-  u8 ncFlags;          /* Zero or more NC_* flags defined below */
+  u16 ncFlags;         /* Zero or more NC_* flags defined below */
 };
 
 /*
 ** Allowed values for the NameContext, ncFlags field.
+**
+** Note:  NC_MinMaxAgg must have the same value as SF_MinMaxAgg and
+** SQLITE_FUNC_MINMAX.
+** 
 */
-#define NC_AllowAgg  0x01    /* Aggregate functions are allowed here */
+#define NC_AllowAgg  0x0001  /* Aggregate functions are allowed here */
-#define NC_HasAgg    0x02    /* One or more aggregate functions seen */
+#define NC_HasAgg    0x0002  /* One or more aggregate functions seen */
-#define NC_IsCheck   0x04    /* True if resolving names in a CHECK constraint */
+#define NC_IsCheck   0x0004  /* True if resolving names in a CHECK constraint */
-#define NC_InAggFunc 0x08    /* True if analyzing arguments to an agg func */
+#define NC_InAggFunc 0x0008  /* True if analyzing arguments to an agg func */
-#define NC_PartIdx   0x10    /* True if resolving a partial index WHERE */
+#define NC_PartIdx   0x0010  /* True if resolving a partial index WHERE */
+#define NC_MinMaxAgg 0x1000  /* min/max aggregates seen.  See note above */
 
 /*
 ** An instance of the following structure contains all information
@@ -2315,13 +2324,13 @@ struct Select {
 #define SF_UsesEphemeral   0x0008  /* Uses the OpenEphemeral opcode */
 #define SF_Expanded        0x0010  /* sqlite3SelectExpand() called on this */
 #define SF_HasTypeInfo     0x0020  /* FROM subqueries have Table metadata */
-                    /*     0x0040  NOT USED */
+#define SF_Compound        0x0040  /* Part of a compound query */
 #define SF_Values          0x0080  /* Synthesized from VALUES clause */
                     /*     0x0100  NOT USED */
 #define SF_NestedFrom      0x0200  /* Part of a parenthesized FROM clause */
 #define SF_MaybeConvert    0x0400  /* Need convertCompoundSelectToSubquery() */
 #define SF_Recursive       0x0800  /* The recursive part of a recursive CTE */
-#define SF_Compound        0x1000  /* Part of a compound query */
+#define SF_MinMaxAgg       0x1000  /* Aggregate containing min() or max() */
 
 
 /*

test/aggnested.test

@@ -156,8 +156,14 @@ do_test aggnested-3.2 {
      (SELECT value1 as xyz, max(x1) AS pqr
         FROM t1
        GROUP BY id1);
+    SELECT
+     (SELECT sum(value2<>xyz) FROM t2)
+    FROM
+     (SELECT value1 as xyz, max(x1) AS pqr
+        FROM t1
+       GROUP BY id1);
   }
-} {0}
+} {1 0}
 do_test aggnested-3.3 {
   db eval {
     DROP TABLE IF EXISTS t1;

test/minmax4.test

@@ -56,14 +56,16 @@ do_test minmax4-1.5 {
 do_test minmax4-1.6 {
   db eval {
     SELECT p, min(q) FROM t1;
+    SELECT p FROM (SELECT p, min(q) FROM t1);
   }
-} {1 2}
+} {1 2 1}
 do_test minmax4-1.7 {
   db eval {
     INSERT INTO t1 VALUES(5,0);
     SELECT p, max(q) FROM t1;
+    SELECT p FROM (SELECT max(q), p FROM t1);
   }
-} {3 4}
+} {3 4 3}
 do_test minmax4-1.8 {
   db eval {
     SELECT p, min(q) FROM t1;
@@ -73,8 +75,9 @@ do_test minmax4-1.9 {
   db eval {
     INSERT INTO t1 VALUES(6,1);
     SELECT p, max(q) FROM t1;
+    SELECT p FROM (SELECT max(q), p FROM t1);
   }
-} {3 4}
+} {3 4 3}
 do_test minmax4-1.10 {
   db eval {
     SELECT p, min(q) FROM t1;