bug#5782

mysql-test/r/ndb_limit.result

@@ -29,3 +29,44 @@ count(*)
 select * from t2 limit 0;
 a	b	c
 drop table t2;
+CREATE TABLE `t2` (
+`views` int(11) NOT NULL default '0',
+`clicks` int(11) NOT NULL default '0',
+`day` date NOT NULL default '0000-00-00',
+`hour` tinyint(4) NOT NULL default '0',
+`bannerid` smallint(6) NOT NULL default '0',
+`zoneid` smallint(6) NOT NULL default '0',
+`source` varchar(50) NOT NULL default '',
+PRIMARY KEY  (`day`,`hour`,`bannerid`,`zoneid`,`source`),
+KEY `bannerid_day` (`bannerid`,`day`),
+KEY `zoneid` (`zoneid`)
+) ENGINE=ndbcluster DEFAULT CHARSET=latin1;
+INSERT INTO `t2` VALUES
+(  1,0,'2004-09-17', 5,100,100,''),
+(  1,0,'2004-09-18', 7,100,100,''),
+( 17,0,'2004-09-27',20,132,100,''),
+(  4,0,'2004-09-16',23,132,100,''),
+( 86,0,'2004-09-18', 7,196,196,''),
+( 11,0,'2004-09-16',16,132,100,''),
+(140,0,'2004-09-18', 0,100,164,''),
+(  2,0,'2004-09-17', 7,132,100,''),
+(846,0,'2004-09-27',11,132,164,''),
+(  1,0,'2004-09-18', 8,132,100,''),
+( 22,0,'2004-09-27', 9,164,132,''),
+(711,0,'2004-09-27', 9,100,164,''),
+( 11,0,'2004-09-18', 0,196,132,''),
+( 41,0,'2004-09-27',15,196,132,''),
+( 57,0,'2004-09-18', 2,164,196,'');
+SELECT DATE_FORMAT(day, '%Y%m%d') as date, DATE_FORMAT(day, '%d-%m-%Y')
+as date_formatted FROM t2 GROUP BY day ORDER BY day DESC;
+date	date_formatted
+20040927	27-09-2004
+20040918	18-09-2004
+20040917	17-09-2004
+20040916	16-09-2004
+SELECT DATE_FORMAT(day, '%Y%m%d') as date, DATE_FORMAT(day, '%d-%m-%Y')
+as date_formatted FROM t2 GROUP BY day ORDER BY day DESC LIMIT 2;
+date	date_formatted
+20040927	27-09-2004
+20040918	18-09-2004
+drop table t2;

mysql-test/t/ndb_limit.test

@@ -42,3 +42,41 @@ select count(*) from t2 where c=12345678 limit 1000;
 select * from t2 limit 0;
 
 drop table t2;
+
+CREATE TABLE `t2` (
+  `views` int(11) NOT NULL default '0',
+  `clicks` int(11) NOT NULL default '0',
+  `day` date NOT NULL default '0000-00-00',
+  `hour` tinyint(4) NOT NULL default '0',
+  `bannerid` smallint(6) NOT NULL default '0',
+  `zoneid` smallint(6) NOT NULL default '0',
+  `source` varchar(50) NOT NULL default '',
+  PRIMARY KEY  (`day`,`hour`,`bannerid`,`zoneid`,`source`),
+  KEY `bannerid_day` (`bannerid`,`day`),
+  KEY `zoneid` (`zoneid`)
+) ENGINE=ndbcluster DEFAULT CHARSET=latin1;
+
+INSERT INTO `t2` VALUES
+(  1,0,'2004-09-17', 5,100,100,''),
+(  1,0,'2004-09-18', 7,100,100,''),
+( 17,0,'2004-09-27',20,132,100,''),
+(  4,0,'2004-09-16',23,132,100,''),
+( 86,0,'2004-09-18', 7,196,196,''),
+( 11,0,'2004-09-16',16,132,100,''),
+(140,0,'2004-09-18', 0,100,164,''),
+(  2,0,'2004-09-17', 7,132,100,''),
+(846,0,'2004-09-27',11,132,164,''),
+(  1,0,'2004-09-18', 8,132,100,''),
+( 22,0,'2004-09-27', 9,164,132,''),
+(711,0,'2004-09-27', 9,100,164,''),
+( 11,0,'2004-09-18', 0,196,132,''),
+( 41,0,'2004-09-27',15,196,132,''),
+( 57,0,'2004-09-18', 2,164,196,'');
+
+SELECT DATE_FORMAT(day, '%Y%m%d') as date, DATE_FORMAT(day, '%d-%m-%Y')
+as date_formatted FROM t2 GROUP BY day ORDER BY day DESC;
+
+SELECT DATE_FORMAT(day, '%Y%m%d') as date, DATE_FORMAT(day, '%d-%m-%Y')
+as date_formatted FROM t2 GROUP BY day ORDER BY day DESC LIMIT 2;
+
+drop table t2;

sql/sql_select.cc

@@ -7188,11 +7188,13 @@ test_if_skip_sort_order(JOIN_TAB *tab,ORDER *order,ha_rows select_limit,
 
     for (nr=0; nr < table->keys ; nr++)
     {
-      uint not_used;
+      uint used_key_parts;
       if (keys.is_set(nr))
       {
 	int flag;
-	if ((flag=test_if_order_by_key(order, table, nr, &not_used)))
+	if ((flag=test_if_order_by_key(order, table, nr, &used_key_parts)) > 0 ||
+	    ((flag < 0) && (table->file->index_flags(nr,used_key_parts-1, 1)
+			    & HA_READ_PREV)))
 	{
 	  if (!no_changes)
 	  {