Make sure the min() and max() optimizer works correctly when there

is a LIMIT clause.  Ticket #396. (CVS 1057)

FossilOrigin-Name: c35e50717678703763c696e3e9b265add2ca6454

manifest

@@ -1,5 +1,5 @@
-C In\sthe\ssqlite\sshell,\schange\sthe\sname\sof\sfunction\sgetline()\sto\slocal_getline()\nto\savoid\sa\sclash\swith\sa\slibrary\sfunction.\s\sTicket\s#400.\s(CVS\s1056)
-D 2003-07-18T01:30:59
+C Make\ssure\sthe\smin()\sand\smax()\soptimizer\sworks\scorrectly\swhen\sthere\nis\sa\sLIMIT\sclause.\s\sTicket\s#396.\s(CVS\s1057)
+D 2003-07-19T00:44:14
 F Makefile.in 9ad23ed4ca97f9670c4496432e3fbd4b3760ebde
 F Makefile.linux-gcc b86a99c493a5bfb402d1d9178dcdc4bd4b32f906
 F README f1de682fbbd94899d50aca13d387d1b3fd3be2dd
@@ -43,7 +43,7 @@ F src/parse.y 16aed0e3ed05445fa7f6a4209cc054208c7083c0
 F src/pragma.c 3b4f5a800e7a2145bc1930f323232e297d4eb782
 F src/printf.c 12e45d482ac8abcc6f786fc99e5bed7dd9a51af0
 F src/random.c 19e8e00fe0df32a742f115773f57651be327cabe
-F src/select.c 98385a4f8601aad67fc0532570fe48f9833d912e
+F src/select.c f1f3b2c2f4f30db30d03af2d0ec629ef32cb5a08
 F src/shell.c c2ba26c850874964f5ec1ebf6c43406f28e44c4a
 F src/shell.tcl 27ecbd63dd88396ad16d81ab44f73e6c0ea9d20e
 F src/sqlite.h.in 54619fa5df4c83b22def66bb3d24808fd03dcbae
@@ -95,7 +95,7 @@ F test/main.test 6a851b5992c4881a725a3d9647e629199df8de9d
 F test/malloc.test 7ba32a9ebd3aeed52ae4aaa6d42ca37e444536fd
 F test/memdb.test cd4580f466f34c42354612a375c5adb90447e4c4
 F test/memleak.test a18e6810cae96d2f6f5136920267adbefc8e1e90
-F test/minmax.test b54ac3bc45460a4976b08ef363e05c032418726e
+F test/minmax.test 6d9b6d6ee34f42e2a58dffece1f76d35f446b3af
 F test/misc1.test c7dc2f2bd702d8283e885a64ec0714be26cfb051
 F test/misc2.test 36410e371d3924f7373988935219bda5a52cea4e
 F test/misuse.test a3aa2b18a97e4c409a1fcaff5151a4dd804a0162
@@ -168,7 +168,7 @@ F www/speed.tcl 2f6b1155b99d39adb185f900456d1d592c4832b3
 F www/sqlite.tcl 3c83b08cf9f18aa2d69453ff441a36c40e431604
 F www/tclsqlite.tcl 1db15abeb446aad0caf0b95b8b9579720e4ea331
 F www/vdbe.tcl 9b9095d4495f37697fd1935d10e14c6015e80aa1
-P 93a2c961b17d2459272e2d8654bd4b972f52fbe1
-R cea9e7eb8d5651e94a3de389de60c2cf
+P 558969ee8697180c74308f3f880d3240eb575af1
+R 90dfb91d095ee0113e81156a9aa2c6cc
 U drh
-Z afb3d221554241843a330036de61dbd9
+Z 4035d7869ab09e0fd1a4cac271ac32dd

manifest.uuid

@@ -1 +1 @@
-558969ee8697180c74308f3f880d3240eb575af1
+c35e50717678703763c696e3e9b265add2ca6454

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 1.143 2003/07/16 11:51:36 drh Exp $
+** $Id: select.c,v 1.144 2003/07/19 00:44:14 drh Exp $
 */
 #include "sqliteInt.h"
 
@@ -1852,13 +1852,13 @@ static int simpleMinMaxQuery(Parse *pParse, Select *p, int eDest, int iParm){
     if( pIdx==0 ) return 0;
   }
 
-  /* Identify column names if we will be using the callback.  This
+  /* Identify column types if we will be using the callback.  This
   ** step is skipped if the output is going to a table or a memory cell.
+  ** The column names have already been generated in the calling function.
   */
   v = sqliteGetVdbe(pParse);
   if( v==0 ) return 0;
   if( eDest==SRT_Callback ){
-    generateColumnNames(pParse, p->pSrc, p->pEList);
     generateColumnTypes(pParse, p->pSrc, p->pEList);
   }
 
@@ -2120,14 +2120,6 @@ int sqliteSelect(
     }
   }
 
-  /* Check for the special case of a min() or max() function by itself
-  ** in the result set.
-  */
-  if( simpleMinMaxQuery(pParse, p, eDest, iParm) ){
-    rc = 0;
-    goto select_end;
-  }
-
   /* Begin generating code.
   */
   v = sqliteGetVdbe(pParse);
@@ -2173,6 +2165,14 @@ int sqliteSelect(
     p->nOffset = iMem;
   }
 
+  /* Check for the special case of a min() or max() function by itself
+  ** in the result set.
+  */
+  if( simpleMinMaxQuery(pParse, p, eDest, iParm) ){
+    rc = 0;
+    goto select_end;
+  }
+
   /* Generate code for all sub-queries in the FROM clause
   */
   for(i=0; i<pTabList->nSrc; i++){
@@ -2214,6 +2214,11 @@ int sqliteSelect(
   /* Identify column types if we will be using a callback.  This
   ** step is skipped if the output is going to a destination other
   ** than a callback.
+  **
+  ** We have to do this separately from the creation of column names
+  ** above because if the pTabList contains views then they will not
+  ** have been resolved and we will not know the column types until
+  ** now.
   */
   if( eDest==SRT_Callback ){
     generateColumnTypes(pParse, pTabList, pEList);

test/minmax.test

@@ -13,7 +13,7 @@
 # aggregate min() and max() functions and which are handled as
 # as a special case.
 #
-# $Id: minmax.test,v 1.5 2003/04/17 12:44:25 drh Exp $
+# $Id: minmax.test,v 1.6 2003/07/19 00:44:15 drh Exp $
 
 set testdir [file dirname $argv0]
 source $testdir/tester.tcl
@@ -173,5 +173,44 @@ do_test minmax-5.5 {
   }
 } {999}
 
+# Make sure the min(x) and max(x) optimizations work when there
+# is a LIMIT clause.  Ticket #396.
+#
+do_test minmax-6.1 {
+  execsql {
+    SELECT min(a) FROM t2 LIMIT 1
+  }
+} {1}
+do_test minmax-6.2 {
+  execsql {
+    SELECT max(a) FROM t2 LIMIT 3
+  }
+} {22}
+do_test minmax-6.3 {
+  execsql {
+    SELECT min(a) FROM t2 LIMIT 0,100
+  }
+} {1}
+do_test minmax-6.4 {
+  execsql {
+    SELECT max(a) FROM t2 LIMIT 1,100
+  }
+} {}
+do_test minmax-6.5 {
+  execsql {
+    SELECT min(x) FROM t3 LIMIT 1
+  }
+} {{}}
+do_test minmax-6.6 {
+  execsql {
+    SELECT max(x) FROM t3 LIMIT 0
+  }
+} {}
+do_test minmax-6.7 {
+  execsql {
+    SELECT max(a) FROM t2 LIMIT 0
+  }
+} {}
+
 
 finish_test