Make LIMIT 0 return no rows. LIMIT -1 still returns all rows. Ticket #346. (CVS 1053)

FossilOrigin-Name: a31d0bd90af7cc95f8e36ca8ece21515f872235e

manifest

@@ -1,5 +1,5 @@
-C Allow\snegative\svalues\sfor\sLIMIT\sand\sOFFSET.\s\sAdd\stests\sfor\snegative\sLIMITs\nand\sOFFSETs.\s\sMake\sthe\sOFFSET\swork\seven\sif\sLIMIT\sis\s0\sor\snegative.\s(CVS\s1052)
+C Make\sLIMIT\s0\sreturn\sno\srows.\s\sLIMIT\s-1\sstill\sreturns\sall\srows.\s\sTicket\s#346.\s(CVS\s1053)
-D 2003-07-16T02:19:38
+D 2003-07-16T11:51:36
 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 20a38bc2a63cc2676651013421cdb6a796c017af
+F src/select.c 98385a4f8601aad67fc0532570fe48f9833d912e
 F src/shell.c 3ed268908fd69c8fd4b28dbe415075cbf0e3991a
 F src/shell.tcl 27ecbd63dd88396ad16d81ab44f73e6c0ea9d20e
 F src/sqlite.h.in 54619fa5df4c83b22def66bb3d24808fd03dcbae
@@ -89,7 +89,7 @@ F test/insert2.test c288375a64dad3295044714f0dfed4a193cf067f
 F test/intpkey.test 9320af48415c594afd4e15f8ef0daa272e05502e
 F test/ioerr.test 5dbaf09f96b56ee01cf3edd762b96eb4ad2c9ca4
 F test/join.test 54e770b74fc8cfc7769d5d0bb05657085641b3c4
-F test/limit.test 10991f3f33159a58b42859df3c731cfaf412c76e
+F test/limit.test 87ca391044ae5387cf697f5e3b21acabb03771a3
 F test/lock.test 388a3a10962d2d571c0c1821cc35bf069ee73473
 F test/main.test 6a851b5992c4881a725a3d9647e629199df8de9d
 F test/malloc.test 7ba32a9ebd3aeed52ae4aaa6d42ca37e444536fd
@@ -158,7 +158,7 @@ F www/faq.tcl 88d3b95d9cd8e374772daa3a646c4d107e7f3e9b
 F www/fileformat.tcl ae6ccf3ffddb180a5af173cd6ee102169629762b
 F www/formatchng.tcl ca6cc1cb1bef9bc36f0619049d3c95e749bc6983
 F www/index.tcl a34315cada875af0b098b4c45981da8ab33fe7b6
-F www/lang.tcl 2890eb85809c8fca20c1d81fa30fbdbceecc2a43
+F www/lang.tcl 06b825c1e88266866da3a915d0e039249ea2e4e0
 F www/mingw.tcl d96b451568c5d28545fefe0c80bee3431c73f69c
 F www/nulls.tcl 4ac1c9bbb8a20a76500d18d63b383f51bb7d8be7
 F www/omitted.tcl fe59eaa9c1459cbf08fa7daa83421bfc814331bb
@@ -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 96e3c539586bf86c4fe8de0ac25de6655f704035
+P e6a752bfef24f773973c151c6262ff331a9dc57a
-R d3b2a0cf306874e50accca7303d95b51
+R 829f52d48453c3f975be5c03ffb2dee3
 U drh
-Z 6453ea102fcd7011423a94e154aded18
+Z bb5153e89cd8d80bdacd0e5c10fcf77d

manifest.uuid

@@ -1 +1 @@
-e6a752bfef24f773973c151c6262ff331a9dc57a
+a31d0bd90af7cc95f8e36ca8ece21515f872235e

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 1.142 2003/07/16 02:19:38 drh Exp $
+** $Id: select.c,v 1.143 2003/07/16 11:51:36 drh Exp $
 */
 #include "sqliteInt.h"
 
@@ -2148,8 +2148,14 @@ int sqliteSelect(
   ** p->nLimit<0 then "LIMIT 0" show no rows at all.
   ** "LIMIT -1" always shows all rows.  There is some
   ** contraversy about what the correct behavior should be.
+  **
+  ** Note that up until this point, the nLimit and nOffset hold
+  ** the numeric values of the limit and offset that appeared in
+  ** the original SQL.  After this code, the nLimit and nOffset hold
+  ** the register number of counters used to track the limit and
+  ** offset.
   */
-  if( p->nLimit<=0 ){
+  if( p->nLimit<0 ){
     p->nLimit = -1;
   }else{
     int iMem = pParse->nMem++;

test/limit.test

@@ -12,7 +12,7 @@
 # focus of this file is testing the LIMIT ... OFFSET ... clause
 #  of SELECT statements.
 #
-# $Id: limit.test,v 1.8 2003/07/16 02:19:38 drh Exp $
+# $Id: limit.test,v 1.9 2003/07/16 11:51:36 drh Exp $
 
 set testdir [file dirname $argv0]
 source $testdir/tester.tcl
@@ -194,13 +194,23 @@ do_test limit-6.4 {
 } {3 4}
 do_test limit-6.5 {
   execsql {
-    SELECT * FROM t6 LIMIT 0
+    SELECT * FROM t6 LIMIT -1
   }
 } {1 2 3 4}
 do_test limit-6.6 {
   execsql {
-    SELECT * FROM t6 LIMIT 0 OFFSET 1
+    SELECT * FROM t6 LIMIT -1 OFFSET 1
   }
 } {2 3 4}
+do_test limit-6.7 {
+  execsql {
+    SELECT * FROM t6 LIMIT 0
+  }
+} {}
+do_test limit-6.8 {
+  execsql {
+    SELECT * FROM t6 LIMIT 0 OFFSET 1
+  }
+} {}
 
 finish_test

www/lang.tcl

@@ -1,7 +1,7 @@
 #
 # Run this Tcl script to generate the sqlite.html file.
 #
-set rcsid {$Id: lang.tcl,v 1.63 2003/06/15 23:49:39 drh Exp $}
+set rcsid {$Id: lang.tcl,v 1.64 2003/07/16 11:51:36 drh Exp $}
 
 puts {<html>
 <head>
@@ -1550,7 +1550,7 @@ sort expression may be optionally followed by ASC or DESC to specify
 the sort order.</p>
 
 <p>The LIMIT clause places an upper bound on the number of rows
-returned in the result.  A LIMIT of 0 indicates no upper bound.
+returned in the result.  A negative LIMIT indicates no upper bound.
 The optional OFFSET following LIMIT specifies how many
 rows to skip at the beginning of the result set.</p>