SUM returns NULL when it has no inputs. Ticket #1413. (CVS 2678)

FossilOrigin-Name: 6281859425d39c11d82875301fefafad1f08416d

diff --git a/manifest b/manifest
index e4574786d9a325a09da6590270308edf0401d86b..71b2dc340db6a12cb13cbf5e64657077b76e96db 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C A\sSUM()\sof\sall\sNULLs\sreturns\sNULL.\s\sA\sSUM()\sof\snothing\sreturn\s0.\nA\sSUM()\sof\sa\smixture\sof\sNULLs\sand\snumbers\sreturns\sthe\ssum\sof\sthe\nnumbers.\s\sTicket\s#1413.\s(CVS\s2677)
-D 2005-09-08T19:45:58
+C SUM\sreturns\sNULL\swhen\sit\shas\sno\sinputs.\s\sTicket\s#1413.\s(CVS\s2678)
+D 2005-09-08T20:37:43
 F Makefile.in 12784cdce5ffc8dfb707300c34e4f1eb3b8a14f1
 F Makefile.linux-gcc 06be33b2a9ad4f005a5f42b22c4a19dab3cbb5c7
 F README 9c4e2d6706bdcc3efdd773ce752a8cdab4f90028
@@ -41,7 +41,7 @@ F src/date.c 7444b0900a28da77e57e3337a636873cff0ae940
 F src/delete.c 16a0e19460b14d219f39ff5c7a9eef808aa1969c
 F src/experimental.c 50c1e3b34f752f4ac10c36f287db095c2b61766d
 F src/expr.c 38f1e135aa80dfc62e253c1e22dd6e194efd2d61
-F src/func.c ebf56befdbecb6570f3fbf42e6e414baf5e2049a
+F src/func.c f63d417248808ff2632a3b576536abffcc21d858
 F src/hash.c 2b1b13f7400e179631c83a1be0c664608c8f021f
 F src/hash.h 1b0c445e1c89ff2aaad9b4605ba61375af001e84
 F src/insert.c 484c73bc1309f283a31baa0e114f3ee980536397
@@ -145,7 +145,7 @@ F test/enc2.test 76c13b8c00beaf95b15c152e95dab51292eb1f0d
 F test/enc3.test f6a5f0b7b7f3a88f030d3143729b87cd5c86d837
 F test/expr.test 71b8cba7fe5c228147c93e530e098144565aaa46
 F test/fkey1.test 153004438d51e6769fb1ce165f6313972d6263ce
-F test/func.test e1f9489e76a1add3ffeecd02038edca130ba759b
+F test/func.test 431f8e07a30aadf2a2a0c8c32f918a497bc4331d
 F test/hook.test f8605cde4c77b2c6a4a73723bf6c507796a64dda
 F test/in.test cead6165aebbe0d451bb2263a307173acfeb6240
 F test/index.test 51e01a0928b4b61228917ddd8c6c0e2466547f6f
@@ -199,9 +199,9 @@ F test/safety.test 907b64fee719554a3622853812af3886fddbbb4f
 F test/schema.test 21cbe7dac652f6d7eb058f3dec369bdbf46bbde6
 F test/select1.test 480233d4f5a81d7d59a55e40d05084d97e57ecdf
 F test/select2.test f3c2678c3a9f3cf08ec4988a3845bda64be6d9e3
-F test/select3.test 551e25e97baf4ed3ec1d3d99776f936517938e60
+F test/select3.test 576df1a5cc5e01dadae9176384e2d506315afdcf
 F test/select4.test c239f516aa31f42f2ef7c6d7cd01105f08f934ca
-F test/select5.test 2dcd382d1d416bf984cd3030ca9f386488a51ab1
+F test/select5.test cf5c42137d915b5e866c99d018be67dad9ebed75
 F test/select6.test 21b72c56e7cbcefd063fdf9bc6c89342aedabccf
 F test/select7.test 1bf795b948c133a15a2a5e99d3270e652ec58ce6
 F test/sort.test 0c33a8ae1c238377ad197387c3872175f40d3843
@@ -219,7 +219,7 @@ F test/threadtest2.c 97a830d53c24c42290501fdfba4a6e5bdd34748b
 F test/trace.test 9fd28695c463b90c2d32c387a432e01eb26e8ccf
 F test/trans.test 10506dc30305cfb8c4098359f7f6f64786f69c5e
 F test/trigger1.test 152aed5a1fa90709fe171f2ca501a6b7f7901479
-F test/trigger2.test f85ee0db543c6303a23f7037cd48534dbb2d1796
+F test/trigger2.test dea71f4b05e22896e72527278bc8ef71b7475bf2
 F test/trigger3.test 9102fd3933db294dc654b5aee9edfe9e94f2b9e2
 F test/trigger4.test 9615207f3746b1f3965113007869e45a895d2497
 F test/trigger5.test 619391a3e9fc194081d22cefd830d811e7badf83
@@ -286,7 +286,7 @@ F www/fullscanb.gif f7c94cb227f060511f8909e10f570157263e9a25
 F www/index-ex1-x-b.gif f9b1d85c3fa2435cf38b15970c7e3aa1edae23a3
 F www/index.tcl 853525c11fb519dac801bcbbe0488c447e526e7b
 F www/indirect1b1.gif adfca361d2df59e34f9c5cac52a670c2bfc303a1
-F www/lang.tcl 422b21b899f6d84dd3fdd2d4b204061b6912efd2
+F www/lang.tcl 7fd48a2d1866a58bca4d43808aed991616bf198d
 F www/lockingv3.tcl f59b19d6c8920a931f096699d6faaf61c05db55f
 F www/mingw.tcl d96b451568c5d28545fefe0c80bee3431c73f69c
 F www/nulls.tcl ec35193f92485b87b90a994a01d0171b58823fcf
@@ -306,7 +306,7 @@ F www/tclsqlite.tcl 3df553505b6efcad08f91e9b975deb2e6c9bb955
 F www/vdbe.tcl 87a31ace769f20d3627a64fa1fade7fed47b90d0
 F www/version3.tcl a99cf5f6d8bd4d5537584a2b342f0fb9fa601d8b
 F www/whentouse.tcl 97e2b5cd296f7d8057e11f44427dea8a4c2db513
-P 48f6a331efea419fe948cd366f9c60ae41edddfd
-R 37364513cd59bb3038c4f5a7cd9fbfba
+P 2e6230edfd651b40481ebad8aa01a22ac92ce80c
+R a88a293bb05baabbecb6ecb073a9f526
 U drh
-Z 7b39a84184f0dd170c44b611c8879606
+Z d9f9df11ed266877677e4103d7412fad

diff --git a/manifest.uuid b/manifest.uuid
index 8a250969c4243e7c653ea1b7b72fbf6b7b3214e5..85716b801c38d697ced5411715395a3e52292b10 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-2e6230edfd651b40481ebad8aa01a22ac92ce80c
\ No newline at end of file
+6281859425d39c11d82875301fefafad1f08416d
\ No newline at end of file

diff --git a/src/func.c b/src/func.c
index 7d0a73c15a6cf32cd3ecc6ecd613ea7e3733cabe..ed9133c3509edfb9f64b98d358fcf37d696d173c 100644 (file)
--- a/src/func.c
+++ b/src/func.c
@@ -16,7 +16,7 @@
 ** sqliteRegisterBuildinFunctions() found at the bottom of the file.
 ** All other code has file scope.
 **
-** $Id: func.c,v 1.109 2005/09/08 19:45:58 drh Exp $
+** $Id: func.c,v 1.110 2005/09/08 20:37:43 drh Exp $
 */
 #include "sqliteInt.h"
 #include <ctype.h>
@@ -842,12 +842,12 @@ static void sumStep(sqlite3_context *context, int argc, sqlite3_value **argv){
 static void sumFinalize(sqlite3_context *context){
   SumCtx *p;
   p = sqlite3_aggregate_context(context, 0);
-  if( p==0 ){
-    sqlite3_result_int(context, 0);
-  }else if( p->seenFloat ){
-    sqlite3_result_double(context, p->sum);
-  }else if( p->cnt>0 ){
-    sqlite3_result_int64(context, (i64)p->sum);
+  if( p && p->cnt>0 ){
+    if( p->seenFloat ){
+      sqlite3_result_double(context, p->sum);
+    }else{
+      sqlite3_result_int64(context, (i64)p->sum);
+    }
   }
 }
 static void avgFinalize(sqlite3_context *context){

diff --git a/test/func.test b/test/func.test
index 01e6914ade2c05ca5106a8ebb3c90434af8ceb38..ea11fc30b549b92cc9708fd36f48d63f19c09e91 100644 (file)
--- a/test/func.test
+++ b/test/func.test
@@ -11,7 +11,7 @@
 # This file implements regression tests for SQLite library.  The
 # focus of this file is testing built-in functions.
 #
-# $Id: func.test,v 1.39 2005/09/08 19:45:58 drh Exp $
+# $Id: func.test,v 1.40 2005/09/08 20:37:44 drh Exp $
 
 set testdir [file dirname $argv0]
 source $testdir/tester.tcl
@@ -513,14 +513,14 @@ do_test func-18.2 {
   }
 } {9902.0}
 
-# The sum of nothing is 0.  But the sum of all NULLs is NULL.
+# The sum of nothing is NULL.  But the sum of all NULLs is NULL.
 #
 do_test func-18.3 {
   execsql {
     DELETE FROM t5;
     SELECT sum(x) FROM t5;
   }
-} {0}
+} {{}}
 do_test func-18.4 {
   execsql {
     INSERT INTO t5 VALUES(NULL);

diff --git a/test/select3.test b/test/select3.test
index c9a6a90807e6c894e075ee70d2286b358816e8f4..3aa605a6d2e79a1ceb7a93798077baf27b9537bf 100644 (file)
--- a/test/select3.test
+++ b/test/select3.test
@@ -12,7 +12,7 @@
 # focus of this file is testing aggregate functions and the
 # GROUP BY and HAVING clauses of SELECT statements.
 #
-# $Id: select3.test,v 1.15 2005/09/08 12:57:28 drh Exp $
+# $Id: select3.test,v 1.16 2005/09/08 20:37:44 drh Exp $
 
 set testdir [file dirname $argv0]
 source $testdir/tester.tcl
@@ -233,7 +233,7 @@ do_test select3-7.2 {
   execsql {
     SELECT a, sum(b) FROM t2 WHERE b=5;
   }
-} {{} 0}
+} {{} {}}
 
 
 finish_test

diff --git a/test/select5.test b/test/select5.test
index 01b737857c814849da966b0f8d2c38a41a157123..ee227881b85f59929cc2fb3bcfc7ce7ab4cf3b8f 100644 (file)
--- a/test/select5.test
+++ b/test/select5.test
@@ -12,7 +12,7 @@
 # focus of this file is testing aggregate functions and the
 # GROUP BY and HAVING clauses of SELECT statements.
 #
-# $Id: select5.test,v 1.12 2005/09/08 10:37:01 drh Exp $
+# $Id: select5.test,v 1.13 2005/09/08 20:37:44 drh Exp $
 
 set testdir [file dirname $argv0]
 source $testdir/tester.tcl
@@ -118,7 +118,7 @@ do_test select5-4.5 {
   execsql {
     SELECT sum(x) FROM t1 WHERE x>100
   }
-} {0}
+} {{}}
 
 # Some tests for queries with a GROUP BY clause but no aggregate functions.
 #

diff --git a/test/trigger2.test b/test/trigger2.test
index a15d4cc9e466ce0a60fb4a1edca488980991065d..1a057e3d28e0182f9b7e9dd3b16a040224f723b5 100644 (file)
--- a/test/trigger2.test
+++ b/test/trigger2.test
@@ -93,7 +93,8 @@ ifcapable subquery {
         BEGIN
         INSERT INTO rlog VALUES ( (SELECT coalesce(max(idx),0) + 1 FROM rlog), 
          old.a, old.b, 
-         (SELECT sum(a) FROM tbl), (SELECT sum(b) FROM tbl), 
+         (SELECT coalesce(sum(a),0) FROM tbl),
+          (SELECT coalesce(sum(b),0) FROM tbl), 
          new.a, new.b);
       END;
   
@@ -101,7 +102,8 @@ ifcapable subquery {
         BEGIN
         INSERT INTO rlog VALUES ( (SELECT coalesce(max(idx),0) + 1 FROM rlog), 
          old.a, old.b, 
-         (SELECT sum(a) FROM tbl), (SELECT sum(b) FROM tbl), 
+         (SELECT coalesce(sum(a),0) FROM tbl),
+          (SELECT coalesce(sum(b),0) FROM tbl), 
          new.a, new.b);
       END;
   
@@ -110,7 +112,8 @@ ifcapable subquery {
         BEGIN
         INSERT INTO clog VALUES ( (SELECT coalesce(max(idx),0) + 1 FROM clog), 
          old.a, old.b, 
-         (SELECT sum(a) FROM tbl), (SELECT sum(b) FROM tbl), 
+         (SELECT coalesce(sum(a),0) FROM tbl),
+          (SELECT coalesce(sum(b),0) FROM tbl), 
          new.a, new.b);
       END;
     }
@@ -140,7 +143,8 @@ ifcapable subquery {
         BEGIN
         INSERT INTO rlog VALUES ( (SELECT coalesce(max(idx),0) + 1 FROM rlog), 
          old.a, old.b, 
-         (SELECT sum(a) FROM tbl), (SELECT sum(b) FROM tbl), 
+         (SELECT coalesce(sum(a),0) FROM tbl),
+          (SELECT coalesce(sum(b),0) FROM tbl), 
          0, 0);
       END;
   
@@ -148,7 +152,8 @@ ifcapable subquery {
         BEGIN
         INSERT INTO rlog VALUES ( (SELECT coalesce(max(idx),0) + 1 FROM rlog), 
          old.a, old.b, 
-         (SELECT sum(a) FROM tbl), (SELECT sum(b) FROM tbl), 
+         (SELECT coalesce(sum(a),0) FROM tbl),
+          (SELECT coalesce(sum(b),0) FROM tbl), 
          0, 0);
       END;
     }
@@ -172,7 +177,8 @@ ifcapable subquery {
         BEGIN
         INSERT INTO rlog VALUES ( (SELECT coalesce(max(idx),0) + 1 FROM rlog), 
          0, 0,
-         (SELECT sum(a) FROM tbl), (SELECT sum(b) FROM tbl), 
+         (SELECT coalesce(sum(a),0) FROM tbl),
+          (SELECT coalesce(sum(b),0) FROM tbl), 
          new.a, new.b);
       END;
   
@@ -180,7 +186,8 @@ ifcapable subquery {
         BEGIN
         INSERT INTO rlog VALUES ( (SELECT coalesce(max(idx),0) + 1 FROM rlog), 
          0, 0,
-         (SELECT sum(a) FROM tbl), (SELECT sum(b) FROM tbl), 
+         (SELECT coalesce(sum(a),0) FROM tbl),
+          (SELECT coalesce(sum(b),0) FROM tbl), 
          new.a, new.b);
       END;
     }

diff --git a/www/lang.tcl b/www/lang.tcl
index 1c46b013854e77c5644d07058006aba94e53c5f9..36c187a067ff42e1e729b3fea74d11940a65b937 100644 (file)
--- a/www/lang.tcl
+++ b/www/lang.tcl
@@ -1,7 +1,7 @@
 #
 # Run this Tcl script to generate the lang-*.html files.
 #
-set rcsid {$Id: lang.tcl,v 1.98 2005/08/28 17:00:26 drh Exp $}
+set rcsid {$Id: lang.tcl,v 1.99 2005/09/08 20:37:44 drh Exp $}
 source common.tcl
 
 if {[llength $argv]>0} {
@@ -1360,7 +1360,8 @@ API.</p>
 <table border=0 cellpadding=10>
 <tr>
 <td valign="top" align="right" width=120>avg(<i>X</i>)</td>
-<td valign="top">Return the average value of all <i>X</i> within a group.</td>
+<td valign="top">Return the average value of all non-NULL <i>X</i> within a
+group.  Non-numeric values are interpreted as 0.</td>
 </tr>
 
 <tr>
@@ -1385,7 +1386,15 @@ if all values in the group are NULL.</td>
 
 <tr>
 <td valign="top" align="right">sum(<i>X</i>)</td>
-<td valign="top">Return the numeric sum of all values in the group.</td>
+<td valign="top">Return the numeric sum of all numeric values in the group.
+   If there are no input rows or all values are NULL, then NULL is returned.
+   NULL is not a helpful result in that case (the correct answer should be
+   zero) but it is what the SQL standard requires and how 
+   most other SQL database engines operate so SQLite does it that way
+   in order to be compatible. 
+   You will probably want to use
+   "<b>coalesce(sum(</b>X<b>),0)</b>" instead of just "<b>sum(</b>X<b>)</b>"
+   to work around this design problem in the SQL language.</td>
 </tr>
 </table>
 }