drop table if exists t1,t2,t3; SELECT 1 FROM (SELECT 1) as a GROUP BY SUM(1); ERROR HY000: Invalid use of group function CREATE TABLE t1 ( spID int(10) unsigned, userID int(10) unsigned, score smallint(5) unsigned, lsg char(40), date date ); INSERT INTO t1 VALUES (1,1,1,'','0000-00-00'); INSERT INTO t1 VALUES (2,2,2,'','0000-00-00'); INSERT INTO t1 VALUES (2,1,1,'','0000-00-00'); INSERT INTO t1 VALUES (3,3,3,'','0000-00-00'); CREATE TABLE t2 ( userID int(10) unsigned NOT NULL auto_increment, niName char(15), passwd char(8), mail char(50), isAukt enum('N','Y') DEFAULT 'N', vName char(30), nName char(40), adr char(60), plz char(5), ort char(35), land char(20), PRIMARY KEY (userID) ); INSERT INTO t2 VALUES (1,'name','pass','mail','Y','v','n','adr','1','1','1'); INSERT INTO t2 VALUES (2,'name','pass','mail','Y','v','n','adr','1','1','1'); INSERT INTO t2 VALUES (3,'name','pass','mail','Y','v','n','adr','1','1','1'); INSERT INTO t2 VALUES (4,'name','pass','mail','Y','v','n','adr','1','1','1'); INSERT INTO t2 VALUES (5,'name','pass','mail','Y','v','n','adr','1','1','1'); SELECT t2.userid, MIN(t1.score) FROM t1, t2 WHERE t1.userID=t2.userID GROUP BY t2.userid; userid MIN(t1.score) 1 1 2 2 3 3 SELECT t2.userid, MIN(t1.score) FROM t1, t2 WHERE t1.userID=t2.userID GROUP BY t2.userid ORDER BY NULL; userid MIN(t1.score) 1 1 2 2 3 3 SELECT t2.userid, MIN(t1.score) FROM t1, t2 WHERE t1.userID=t2.userID AND t1.spID=2 GROUP BY t2.userid; userid MIN(t1.score) 1 1 2 2 SELECT t2.userid, MIN(t1.score+0.0) FROM t1, t2 WHERE t1.userID=t2.userID AND t1.spID=2 GROUP BY t2.userid; userid MIN(t1.score+0.0) 1 1.0 2 2.0 SELECT t2.userid, MIN(t1.score+0.0) FROM t1, t2 WHERE t1.userID=t2.userID AND t1.spID=2 GROUP BY t2.userid ORDER BY NULL; userid MIN(t1.score+0.0) 2 2.0 1 1.0 EXPLAIN SELECT t2.userid, MIN(t1.score+0.0) FROM t1, t2 WHERE t1.userID=t2.userID AND t1.spID=2 GROUP BY t2.userid ORDER BY NULL; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ALL NULL NULL NULL NULL 4 Using where; Using temporary 1 SIMPLE t2 eq_ref PRIMARY PRIMARY 4 test.t1.userID 1 Using index drop table t1,t2; CREATE TABLE t1 ( PID int(10) unsigned NOT NULL auto_increment, payDate date DEFAULT '0000-00-00' NOT NULL, recDate datetime DEFAULT '0000-00-00 00:00:00' NOT NULL, URID int(10) unsigned DEFAULT '0' NOT NULL, CRID int(10) unsigned DEFAULT '0' NOT NULL, amount int(10) unsigned DEFAULT '0' NOT NULL, operator int(10) unsigned, method enum('unknown','cash','dealer','check','card','lazy','delayed','test') DEFAULT 'unknown' NOT NULL, DIID int(10) unsigned, reason char(1) binary DEFAULT '' NOT NULL, code_id int(10) unsigned, qty mediumint(8) unsigned DEFAULT '0' NOT NULL, PRIMARY KEY (PID), KEY URID (URID), KEY reason (reason), KEY method (method), KEY payDate (payDate) ); INSERT INTO t1 VALUES (1,'1970-01-01','1997-10-17 00:00:00',2529,1,21000,11886,'check',0,'F',16200,6); SELECT COUNT(P.URID),SUM(P.amount),P.method, MIN(PP.recdate+0) > 19980501000000 AS IsNew FROM t1 AS P JOIN t1 as PP WHERE P.URID = PP.URID GROUP BY method,IsNew; ERROR 42000: Can't group on 'IsNew' drop table t1; CREATE TABLE t1 ( cid mediumint(9) NOT NULL auto_increment, firstname varchar(32) DEFAULT '' NOT NULL, surname varchar(32) DEFAULT '' NOT NULL, PRIMARY KEY (cid) ); INSERT INTO t1 VALUES (1,'That','Guy'); INSERT INTO t1 VALUES (2,'Another','Gent'); CREATE TABLE t2 ( call_id mediumint(8) NOT NULL auto_increment, contact_id mediumint(8) DEFAULT '0' NOT NULL, PRIMARY KEY (call_id), KEY contact_id (contact_id) ); lock tables t1 read,t2 write; INSERT INTO t2 VALUES (10,2); INSERT INTO t2 VALUES (18,2); INSERT INTO t2 VALUES (62,2); INSERT INTO t2 VALUES (91,2); INSERT INTO t2 VALUES (92,2); SELECT cid, CONCAT(firstname, ' ', surname), COUNT(call_id) FROM t1 LEFT JOIN t2 ON cid=contact_id WHERE firstname like '%foo%' GROUP BY cid; cid CONCAT(firstname, ' ', surname) COUNT(call_id) SELECT cid, CONCAT(firstname, ' ', surname), COUNT(call_id) FROM t1 LEFT JOIN t2 ON cid=contact_id WHERE firstname like '%foo%' GROUP BY cid ORDER BY NULL; cid CONCAT(firstname, ' ', surname) COUNT(call_id) SELECT HIGH_PRIORITY cid, CONCAT(firstname, ' ', surname), COUNT(call_id) FROM t1 LEFT JOIN t2 ON cid=contact_id WHERE firstname like '%foo%' GROUP BY cid ORDER BY surname, firstname; cid CONCAT(firstname, ' ', surname) COUNT(call_id) drop table t1,t2; unlock tables; CREATE TABLE t1 ( bug_id mediumint(9) NOT NULL auto_increment, groupset bigint(20) DEFAULT '0' NOT NULL, assigned_to mediumint(9) DEFAULT '0' NOT NULL, bug_file_loc text, bug_severity enum('blocker','critical','major','normal','minor','trivial','enhancement') DEFAULT 'blocker' NOT NULL, bug_status enum('','NEW','ASSIGNED','REOPENED','RESOLVED','VERIFIED','CLOSED') DEFAULT 'NEW' NOT NULL, creation_ts datetime DEFAULT '0000-00-00 00:00:00' NOT NULL, delta_ts timestamp, short_desc mediumtext, long_desc mediumtext, op_sys enum('All','Windows 3.1','Windows 95','Windows 98','Windows NT','Windows 2000','Linux','other') DEFAULT 'All' NOT NULL, priority enum('P1','P2','P3','P4','P5') DEFAULT 'P1' NOT NULL, product varchar(64) DEFAULT '' NOT NULL, rep_platform enum('All','PC','VTD-8','Other'), reporter mediumint(9) DEFAULT '0' NOT NULL, version varchar(16) DEFAULT '' NOT NULL, component varchar(50) DEFAULT '' NOT NULL, resolution enum('','FIXED','INVALID','WONTFIX','LATER','REMIND','DUPLICATE','WORKSFORME') DEFAULT '' NOT NULL, target_milestone varchar(20) DEFAULT '' NOT NULL, qa_contact mediumint(9) DEFAULT '0' NOT NULL, status_whiteboard mediumtext NOT NULL, votes mediumint(9) DEFAULT '0' NOT NULL, PRIMARY KEY (bug_id), KEY assigned_to (assigned_to), KEY creation_ts (creation_ts), KEY delta_ts (delta_ts), KEY bug_severity (bug_severity), KEY bug_status (bug_status), KEY op_sys (op_sys), KEY priority (priority), KEY product (product), KEY reporter (reporter), KEY version (version), KEY component (component), KEY resolution (resolution), KEY target_milestone (target_milestone), KEY qa_contact (qa_contact), KEY votes (votes) ); INSERT INTO t1 VALUES (1,0,0,'','normal','','2000-02-10 09:25:12',20000321114747,'','','Linux','P1','TestProduct','PC',3,'other','TestComponent','','M1',0,'',0); INSERT INTO t1 VALUES (9,0,0,'','enhancement','','2000-03-10 11:49:36',20000321114747,'','','All','P5','AAAAA','PC',3,'2.00 CD - Pre','BBBBBBBBBBBBB - conversion','','',0,'',0); INSERT INTO t1 VALUES (10,0,0,'','enhancement','','2000-03-10 18:10:16',20000321114747,'','','All','P4','AAAAA','PC',3,'2.00 CD - Pre','BBBBBBBBBBBBB - conversion','','',0,'',0); INSERT INTO t1 VALUES (7,0,0,'','critical','','2000-03-09 10:50:21',20000321114747,'','','All','P1','AAAAA','PC',3,'2.00 CD - Pre','BBBBBBBBBBBBB - generic','','',0,'',0); INSERT INTO t1 VALUES (6,0,0,'','normal','','2000-03-09 10:42:44',20000321114747,'','','All','P2','AAAAA','PC',3,'2.00 CD - Pre','kkkkkkkkkkk lllllllllll','','',0,'',0); INSERT INTO t1 VALUES (8,0,0,'','major','','2000-03-09 11:32:14',20000321114747,'','','All','P3','AAAAA','PC',3,'2.00 CD - Pre','kkkkkkkkkkk lllllllllll','','',0,'',0); INSERT INTO t1 VALUES (5,0,0,'','enhancement','','2000-03-09 10:38:59',20000321114747,'','','All','P5','CCC/CCCCCC','PC',5,'7.00','Administration','','',0,'',0); INSERT INTO t1 VALUES (4,0,0,'','normal','','2000-03-08 18:32:14',20000321114747,'','','other','P2','TestProduct','Other',3,'other','TestComponent2','','',0,'',0); INSERT INTO t1 VALUES (3,0,0,'','normal','','2000-03-08 18:30:52',20000321114747,'','','other','P2','TestProduct','Other',3,'other','TestComponent','','',0,'',0); INSERT INTO t1 VALUES (2,0,0,'','enhancement','','2000-03-08 18:24:51',20000321114747,'','','All','P2','TestProduct','Other',4,'other','TestComponent2','','',0,'',0); INSERT INTO t1 VALUES (11,0,0,'','blocker','','2000-03-13 09:43:41',20000321114747,'','','All','P2','CCC/CCCCCC','PC',5,'7.00','DDDDDDDDD','','',0,'',0); INSERT INTO t1 VALUES (12,0,0,'','normal','','2000-03-13 16:14:31',20000321114747,'','','All','P2','AAAAA','PC',3,'2.00 CD - Pre','kkkkkkkkkkk lllllllllll','','',0,'',0); INSERT INTO t1 VALUES (13,0,0,'','normal','','2000-03-15 16:20:44',20000321114747,'','','other','P2','TestProduct','Other',3,'other','TestComponent','','',0,'',0); INSERT INTO t1 VALUES (14,0,0,'','blocker','','2000-03-15 18:13:47',20000321114747,'','','All','P1','AAAAA','PC',3,'2.00 CD - Pre','BBBBBBBBBBBBB - generic','','',0,'',0); INSERT INTO t1 VALUES (15,0,0,'','minor','','2000-03-16 18:03:28',20000321114747,'','','All','P2','CCC/CCCCCC','Other',5,'7.00','DDDDDDDDD','','',0,'',0); INSERT INTO t1 VALUES (16,0,0,'','normal','','2000-03-16 18:33:41',20000321114747,'','','All','P2','CCC/CCCCCC','Other',5,'7.00','Administration','','',0,'',0); INSERT INTO t1 VALUES (17,0,0,'','normal','','2000-03-16 18:34:18',20000321114747,'','','All','P2','CCC/CCCCCC','Other',5,'7.00','Administration','','',0,'',0); INSERT INTO t1 VALUES (18,0,0,'','normal','','2000-03-16 18:34:56',20000321114747,'','','All','P2','CCC/CCCCCC','Other',5,'7.00','Administration','','',0,'',0); INSERT INTO t1 VALUES (19,0,0,'','enhancement','','2000-03-16 18:35:34',20000321114747,'','','All','P2','CCC/CCCCCC','Other',5,'7.00','Administration','','',0,'',0); INSERT INTO t1 VALUES (20,0,0,'','enhancement','','2000-03-16 18:36:23',20000321114747,'','','All','P2','CCC/CCCCCC','Other',5,'7.00','Administration','','',0,'',0); INSERT INTO t1 VALUES (21,0,0,'','enhancement','','2000-03-16 18:37:23',20000321114747,'','','All','P2','CCC/CCCCCC','Other',5,'7.00','Administration','','',0,'',0); INSERT INTO t1 VALUES (22,0,0,'','enhancement','','2000-03-16 18:38:16',20000321114747,'','','All','P2','CCC/CCCCCC','Other',5,'7.00','Administration','','',0,'',0); INSERT INTO t1 VALUES (23,0,0,'','normal','','2000-03-16 18:58:12',20000321114747,'','','All','P2','CCC/CCCCCC','Other',5,'7.00','DDDDDDDDD','','',0,'',0); INSERT INTO t1 VALUES (24,0,0,'','normal','','2000-03-17 11:08:10',20000321114747,'','','All','P2','AAAAAAAA-AAA','PC',3,'2.8','Web Interface','','',0,'',0); INSERT INTO t1 VALUES (25,0,0,'','normal','','2000-03-17 11:10:45',20000321114747,'','','All','P2','AAAAAAAA-AAA','PC',3,'2.8','Web Interface','','',0,'',0); INSERT INTO t1 VALUES (26,0,0,'','normal','','2000-03-17 11:15:47',20000321114747,'','','All','P2','AAAAAAAA-AAA','PC',3,'2.8','Web Interface','','',0,'',0); INSERT INTO t1 VALUES (27,0,0,'','normal','','2000-03-17 17:45:41',20000321114747,'','','All','P2','CCC/CCCCCC','PC',5,'7.00','DDDDDDDDD','','',0,'',0); INSERT INTO t1 VALUES (28,0,0,'','normal','','2000-03-20 09:51:45',20000321114747,'','','Windows NT','P2','TestProduct','PC',8,'other','TestComponent','','',0,'',0); INSERT INTO t1 VALUES (29,0,0,'','normal','','2000-03-20 11:15:09',20000321114747,'','','All','P5','AAAAAAAA-AAA','PC',3,'2.8','Web Interface','','',0,'',0); CREATE TABLE t2 ( value tinytext, program varchar(64), initialowner tinytext NOT NULL, initialqacontact tinytext NOT NULL, description mediumtext NOT NULL ); INSERT INTO t2 VALUES ('TestComponent','TestProduct','id0001','',''); INSERT INTO t2 VALUES ('BBBBBBBBBBBBB - conversion','AAAAA','id0001','',''); INSERT INTO t2 VALUES ('BBBBBBBBBBBBB - generic','AAAAA','id0001','',''); INSERT INTO t2 VALUES ('TestComponent2','TestProduct','id0001','',''); INSERT INTO t2 VALUES ('BBBBBBBBBBBBB - eeeeeeeee','AAAAA','id0001','',''); INSERT INTO t2 VALUES ('kkkkkkkkkkk lllllllllll','AAAAA','id0001','',''); INSERT INTO t2 VALUES ('Test Procedures','AAAAA','id0001','',''); INSERT INTO t2 VALUES ('Documentation','AAAAA','id0003','',''); INSERT INTO t2 VALUES ('DDDDDDDDD','CCC/CCCCCC','id0002','',''); INSERT INTO t2 VALUES ('Eeeeeeee Lite','CCC/CCCCCC','id0002','',''); INSERT INTO t2 VALUES ('Eeeeeeee Full','CCC/CCCCCC','id0002','',''); INSERT INTO t2 VALUES ('Administration','CCC/CCCCCC','id0002','',''); INSERT INTO t2 VALUES ('Distribution','CCC/CCCCCC','id0002','',''); INSERT INTO t2 VALUES ('Setup','CCC/CCCCCC','id0002','',''); INSERT INTO t2 VALUES ('Unspecified','CCC/CCCCCC','id0002','',''); INSERT INTO t2 VALUES ('Web Interface','AAAAAAAA-AAA','id0001','',''); INSERT INTO t2 VALUES ('Host communication','AAAAA','id0001','',''); select value,description,bug_id from t2 left join t1 on t2.program=t1.product and t2.value=t1.component where program="AAAAA"; value description bug_id BBBBBBBBBBBBB - conversion 9 BBBBBBBBBBBBB - conversion 10 BBBBBBBBBBBBB - generic 7 BBBBBBBBBBBBB - generic 14 BBBBBBBBBBBBB - eeeeeeeee NULL kkkkkkkkkkk lllllllllll 6 kkkkkkkkkkk lllllllllll 8 kkkkkkkkkkk lllllllllll 12 Test Procedures NULL Documentation NULL Host communication NULL select value,description,COUNT(bug_id) from t2 left join t1 on t2.program=t1.product and t2.value=t1.component where program="AAAAA" group by value; value description COUNT(bug_id) BBBBBBBBBBBBB - conversion 2 BBBBBBBBBBBBB - eeeeeeeee 0 BBBBBBBBBBBBB - generic 2 Documentation 0 Host communication 0 kkkkkkkkkkk lllllllllll 3 Test Procedures 0 select value,description,COUNT(bug_id) from t2 left join t1 on t2.program=t1.product and t2.value=t1.component where program="AAAAA" group by value having COUNT(bug_id) IN (0,2); value description COUNT(bug_id) BBBBBBBBBBBBB - conversion 2 BBBBBBBBBBBBB - eeeeeeeee 0 BBBBBBBBBBBBB - generic 2 Documentation 0 Host communication 0 Test Procedures 0 drop table t1,t2; create table t1 (foo int); insert into t1 values (1); select 1+1, "a",count(*) from t1 where foo in (2); 1+1 a count(*) 2 a 0 insert into t1 values (1); select 1+1,"a",count(*) from t1 where foo in (2); 1+1 a count(*) 2 a 0 drop table t1; CREATE TABLE t1 ( spID int(10) unsigned, userID int(10) unsigned, score smallint(5) unsigned, key (spid), key (score) ); INSERT INTO t1 VALUES (1,1,1),(2,2,2),(2,1,1),(3,3,3),(4,3,3),(5,3,3),(6,3,3),(7,3,3); explain select userid,count(*) from t1 group by userid desc; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ALL NULL NULL NULL NULL 8 Using temporary; Using filesort explain select userid,count(*) from t1 group by userid desc order by null; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ALL NULL NULL NULL NULL 8 Using temporary select userid,count(*) from t1 group by userid desc; userid count(*) 3 5 2 1 1 2 select userid,count(*) from t1 group by userid desc having (count(*)+1) IN (4,3); userid count(*) 1 2 select userid,count(*) from t1 group by userid desc having 3 IN (1,COUNT(*)); userid count(*) explain select spid,count(*) from t1 where spid between 1 and 2 group by spid desc; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range spID spID 5 NULL 3 Using where; Using index explain select spid,count(*) from t1 where spid between 1 and 2 group by spid; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range spID spID 5 NULL 3 Using where; Using index explain select spid,count(*) from t1 where spid between 1 and 2 group by spid order by null; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range spID spID 5 NULL 3 Using where; Using index select spid,count(*) from t1 where spid between 1 and 2 group by spid; spid count(*) 1 1 2 2 select spid,count(*) from t1 where spid between 1 and 2 group by spid desc; spid count(*) 2 2 1 1 explain extended select sql_big_result spid,sum(userid) from t1 group by spid desc; id select_type table type possible_keys key key_len ref rows filtered Extra 1 SIMPLE t1 ALL NULL NULL NULL NULL 8 100.00 Using filesort Warnings: Note 1003 select sql_big_result `test`.`t1`.`spID` AS `spid`,sum(`test`.`t1`.`userID`) AS `sum(userid)` from `test`.`t1` group by `test`.`t1`.`spID` desc explain select sql_big_result spid,sum(userid) from t1 group by spid desc order by null; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ALL NULL NULL NULL NULL 8 Using filesort select sql_big_result spid,sum(userid) from t1 group by spid desc; spid sum(userid) 7 3 6 3 5 3 4 3 3 3 2 3 1 1 explain select sql_big_result score,count(*) from t1 group by score desc; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 index NULL score 3 NULL 8 Using index; Using filesort explain select sql_big_result score,count(*) from t1 group by score desc order by null; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 index NULL score 3 NULL 8 Using index; Using filesort select sql_big_result score,count(*) from t1 group by score desc; score count(*) 3 5 2 1 1 2 drop table t1; create table t1 (a date default null, b date default null); insert t1 values ('1999-10-01','2000-01-10'), ('1997-01-01','1998-10-01'); select a,min(b) c,count(distinct rand()) from t1 group by a having c2 and cqty>1; id sqty cqty 1 5 2 2 9 2 select id, sum(qty) as sqty from t1 group by id having sqty>2 and count(qty)>1; id sqty 1 5 2 9 select id, sum(qty) as sqty, count(qty) as cqty from t1 group by id having sqty>2 and cqty>1; id sqty cqty 1 5 2 2 9 2 select id, sum(qty) as sqty, count(qty) as cqty from t1 group by id having sum(qty)>2 and count(qty)>1; id sqty cqty 1 5 2 2 9 2 select count(*), case interval(qty,2,3,4,5,6,7,8) when -1 then NULL when 0 then "zero" when 1 then "one" when 2 then "two" end as category from t1 group by category; count(*) category 2 NULL 1 one 1 two select count(*), interval(qty,2,3,4,5,6,7,8) as category from t1 group by category; count(*) category 1 1 1 2 1 3 1 4 drop table t1; CREATE TABLE t1 ( userid int(10) unsigned, score smallint(5) unsigned, key (score) ); INSERT INTO t1 VALUES (1,1),(2,2),(1,1),(3,3),(3,3),(3,3),(3,3),(3,3); SELECT userid,count(*) FROM t1 GROUP BY userid DESC; userid count(*) 3 5 2 1 1 2 EXPLAIN SELECT userid,count(*) FROM t1 GROUP BY userid DESC; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ALL NULL NULL NULL NULL 8 Using temporary; Using filesort DROP TABLE t1; CREATE TABLE t1 ( i int(11) default NULL, j int(11) default NULL ); INSERT INTO t1 VALUES (1,2),(2,3),(4,5),(3,5),(1,5),(23,5); SELECT i, COUNT(DISTINCT(i)) FROM t1 GROUP BY j ORDER BY NULL; i COUNT(DISTINCT(i)) 1 1 2 1 4 4 explain SELECT i, COUNT(DISTINCT(i)) FROM t1 GROUP BY j ORDER BY NULL; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ALL NULL NULL NULL NULL 6 Using filesort DROP TABLE t1; create table t1 (a int); insert into t1 values(null); select min(a) is null from t1; min(a) is null 1 select min(a) is null or null from t1; min(a) is null or null 1 select 1 and min(a) is null from t1; 1 and min(a) is null 1 drop table t1; create table t1 ( col1 int, col2 int ); insert into t1 values (1,1),(1,2),(1,3),(2,1),(2,2); select group_concat( distinct col1 ) as alias from t1 group by col2 having alias like '%'; alias 1,2 1,2 1 drop table t1; create table t1 (a integer, b integer, c integer); insert into t1 (a,b) values (1,2),(1,3),(2,5); select a, 0.1*0+1 r2, sum(1) r1 from t1 where a = 1 group by a having r1>1 and r2=1; a r2 r1 1 1.0 2 select a, round(rand(100)*10) r2, sum(1) r1 from t1 where a = 1 group by a having r1>1 and r2<=2; a r2 r1 1 2 2 select a,sum(b) from t1 where a=1 group by c; a sum(b) 1 5 select a*sum(b) from t1 where a=1 group by c; a*sum(b) 5 select sum(a)*sum(b) from t1 where a=1 group by c; sum(a)*sum(b) 10 select a,sum(b) from t1 where a=1 group by c having a=1; a sum(b) 1 5 select a as d,sum(b) from t1 where a=1 group by c having d=1; d sum(b) 1 5 select sum(a)*sum(b) as d from t1 where a=1 group by c having d > 0; d 10 drop table t1; create table t1(a int); insert into t1 values (0),(1),(2),(3),(4),(5),(6),(8),(9); create table t2 ( a int, b varchar(200) NOT NULL, c varchar(50) NOT NULL, d varchar(100) NOT NULL, primary key (a,b(132),c,d), key a (a,b) ) charset=utf8; insert into t2 select x3.a, -- 3 concat('val-', x3.a + 3*x4.a), -- 12 concat('val-', @a:=x3.a + 3*x4.a + 12*C.a), -- 120 concat('val-', @a + 120*D.a) from t1 x3, t1 x4, t1 C, t1 D where x3.a < 3 and x4.a < 4 and D.a < 4; delete from t2 where a = 2 and b = 'val-2' order by a,b,c,d limit 30; explain select c from t2 where a = 2 and b = 'val-2' group by c; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t2 ref PRIMARY,a PRIMARY 402 const,const 6 Using where select c from t2 where a = 2 and b = 'val-2' group by c; c val-74 val-98 drop table t1,t2; create table t1 (b int4 unsigned not null); insert into t1 values(3000000000); select * from t1; b 3000000000 select min(b) from t1; min(b) 3000000000 drop table t1; CREATE TABLE t1 (id int PRIMARY KEY, user_id int, hostname longtext); INSERT INTO t1 VALUES (1, 7, 'cache-dtc-af05.proxy.aol.com'), (2, 3, 'what.ever.com'), (3, 7, 'cache-dtc-af05.proxy.aol.com'), (4, 7, 'cache-dtc-af05.proxy.aol.com'); SELECT hostname, COUNT(DISTINCT user_id) as no FROM t1 WHERE hostname LIKE '%aol%' GROUP BY hostname; hostname no cache-dtc-af05.proxy.aol.com 1 DROP TABLE t1; CREATE TABLE t1 (a int, b int); INSERT INTO t1 VALUES (1,2), (1,3); SELECT a, b FROM t1 GROUP BY 'const'; a b 1 2 SELECT DISTINCT a, b FROM t1 GROUP BY 'const'; a b 1 2 DROP TABLE t1; CREATE TABLE t1 (id INT, dt DATETIME); INSERT INTO t1 VALUES ( 1, '2005-05-01 12:30:00' ); INSERT INTO t1 VALUES ( 1, '2005-05-01 12:30:00' ); INSERT INTO t1 VALUES ( 1, '2005-05-01 12:30:00' ); INSERT INTO t1 VALUES ( 1, '2005-05-01 12:30:00' ); SELECT dt DIV 1 AS f, id FROM t1 GROUP BY f; f id 20050501123000 1 DROP TABLE t1; CREATE TABLE t1 (id varchar(20) NOT NULL); INSERT INTO t1 VALUES ('trans1'), ('trans2'); CREATE TABLE t2 (id varchar(20) NOT NULL, err_comment blob NOT NULL); INSERT INTO t2 VALUES ('trans1', 'a problem'); SELECT COUNT(DISTINCT(t1.id)), LEFT(err_comment, 256) AS comment FROM t1 LEFT JOIN t2 ON t1.id=t2.id GROUP BY comment; COUNT(DISTINCT(t1.id)) comment 1 NULL 1 a problem DROP TABLE t1, t2; create table t1 (f1 date); insert into t1 values('2005-06-06'); insert into t1 values('2005-06-06'); select date(left(f1+0,8)) from t1 group by 1; date(left(f1+0,8)) 2005-06-06 drop table t1; CREATE TABLE t1 (n int); INSERT INTO t1 VALUES (1); SELECT n+1 AS n FROM t1 GROUP BY n; n 2 Warnings: Warning 1052 Column 'n' in group statement is ambiguous DROP TABLE t1; create table t1(f1 varchar(5) key); insert into t1 values (1),(2); select sql_buffer_result max(f1) is null from t1; max(f1) is null 0 select sql_buffer_result max(f1)+1 from t1; max(f1)+1 3 drop table t1; CREATE TABLE t1(a INT); INSERT INTO t1 VALUES (1),(2); SELECT a FROM t1 GROUP BY 'a'; a 1 SELECT a FROM t1 GROUP BY "a"; a 1 SELECT a FROM t1 GROUP BY `a`; a 1 2 set sql_mode=ANSI_QUOTES; SELECT a FROM t1 GROUP BY "a"; a 1 2 SELECT a FROM t1 GROUP BY 'a'; a 1 SELECT a FROM t1 GROUP BY `a`; a 1 2 set sql_mode=''; SELECT a FROM t1 HAVING 'a' > 1; a Warnings: Warning 1292 Truncated incorrect DOUBLE value: 'a' SELECT a FROM t1 HAVING "a" > 1; a Warnings: Warning 1292 Truncated incorrect DOUBLE value: 'a' SELECT a FROM t1 HAVING `a` > 1; a 2 SELECT a FROM t1 ORDER BY 'a' DESC; a 1 2 SELECT a FROM t1 ORDER BY "a" DESC; a 1 2 SELECT a FROM t1 ORDER BY `a` DESC; a 2 1 DROP TABLE t1; CREATE TABLE t1 ( f1 int(10) unsigned NOT NULL auto_increment primary key, f2 varchar(100) NOT NULL default '' ); CREATE TABLE t2 ( f1 varchar(10) NOT NULL default '', f2 char(3) NOT NULL default '', PRIMARY KEY (`f1`), KEY `k1` (`f2`,`f1`) ); INSERT INTO t1 values(NULL, ''); INSERT INTO `t2` VALUES ('486878','WDT'),('486910','WDT'); SELECT SQL_BUFFER_RESULT avg(t2.f1) FROM t1, t2 where t2.f2 = 'SIR' GROUP BY t1.f1; avg(t2.f1) SELECT avg(t2.f1) FROM t1, t2 where t2.f2 = 'SIR' GROUP BY t1.f1; avg(t2.f1) DROP TABLE t1, t2; create table t1 (c1 char(3), c2 char(3)); create table t2 (c3 char(3), c4 char(3)); insert into t1 values ('aaa', 'bb1'), ('aaa', 'bb2'); insert into t2 values ('aaa', 'bb1'), ('aaa', 'bb2'); select t1.c1 as c2 from t1, t2 where t1.c2 = t2.c4 group by c2; c2 aaa aaa Warnings: Warning 1052 Column 'c2' in group statement is ambiguous show warnings; Level Code Message Warning 1052 Column 'c2' in group statement is ambiguous select t1.c1 as c2 from t1, t2 where t1.c2 = t2.c4 group by t1.c1; c2 aaa show warnings; Level Code Message drop table t1, t2; CREATE TABLE t1 (a tinyint(3), b varchar(255), PRIMARY KEY (a)); INSERT INTO t1 VALUES (1,'-----'), (6,'Allemagne'), (17,'Autriche'), (25,'Belgique'), (54,'Danemark'), (62,'Espagne'), (68,'France'); CREATE TABLE t2 (a tinyint(3), b tinyint(3), PRIMARY KEY (a), KEY b (b)); INSERT INTO t2 VALUES (1,1), (2,1), (6,6), (18,17), (15,25), (16,25), (17,25), (10,54), (5,62),(3,68); CREATE VIEW v1 AS select t1.a, concat(t1.b,'') AS b, t1.b as real_b from t1; explain SELECT straight_join sql_no_cache v1.a, v1.b, v1.real_b from t2, v1 where t2.b=v1.a GROUP BY t2.b; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t2 index b b 2 NULL 10 Using index 1 SIMPLE t1 eq_ref PRIMARY PRIMARY 1 test.t2.b 1 SELECT straight_join sql_no_cache v1.a, v1.b, v1.real_b from t2, v1 where t2.b=v1.a GROUP BY t2.b; a b real_b 1 ----- ----- 6 Allemagne Allemagne 17 Autriche Autriche 25 Belgique Belgique 54 Danemark Danemark 62 Espagne Espagne 68 France France DROP VIEW v1; DROP TABLE t1,t2; CREATE TABLE t1 (a INT PRIMARY KEY, b INT, key (b)); INSERT INTO t1 VALUES (1, 1); INSERT INTO t1 SELECT a + 1 , MOD(a + 1 , 20) FROM t1; INSERT INTO t1 SELECT a + 2 , MOD(a + 2 , 20) FROM t1; INSERT INTO t1 SELECT a + 4 , MOD(a + 4 , 20) FROM t1; INSERT INTO t1 SELECT a + 8 , MOD(a + 8 , 20) FROM t1; INSERT INTO t1 SELECT a + 16, MOD(a + 16, 20) FROM t1; INSERT INTO t1 SELECT a + 32, MOD(a + 32, 20) FROM t1; INSERT INTO t1 SELECT a + 64, MOD(a + 64, 20) FROM t1; SELECT MIN(b), MAX(b) from t1; MIN(b) MAX(b) 0 19 EXPLAIN SELECT b, sum(1) FROM t1 GROUP BY b; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 index NULL b 5 NULL 128 Using index EXPLAIN SELECT SQL_BIG_RESULT b, sum(1) FROM t1 GROUP BY b; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 index NULL b 5 NULL 128 Using index; Using filesort SELECT b, sum(1) FROM t1 GROUP BY b; b sum(1) 0 6 1 7 2 7 3 7 4 7 5 7 6 7 7 7 8 7 9 6 10 6 11 6 12 6 13 6 14 6 15 6 16 6 17 6 18 6 19 6 SELECT SQL_BIG_RESULT b, sum(1) FROM t1 GROUP BY b; b sum(1) 0 6 1 7 2 7 3 7 4 7 5 7 6 7 7 7 8 7 9 6 10 6 11 6 12 6 13 6 14 6 15 6 16 6 17 6 18 6 19 6 DROP TABLE t1; CREATE TABLE t1 (a INT PRIMARY KEY, b INT); INSERT INTO t1 VALUES (1,1),(2,1),(3,2),(4,2),(5,3),(6,3); SET SQL_MODE = 'ONLY_FULL_GROUP_BY'; SELECT MAX(a)-MIN(a) FROM t1 GROUP BY b; MAX(a)-MIN(a) 1 1 1 SELECT CEILING(MIN(a)) FROM t1 GROUP BY b; CEILING(MIN(a)) 1 3 5 SELECT CASE WHEN AVG(a)>=0 THEN 'Positive' ELSE 'Negative' END FROM t1 GROUP BY b; CASE WHEN AVG(a)>=0 THEN 'Positive' ELSE 'Negative' END Positive Positive Positive SELECT a + 1 FROM t1 GROUP BY a; a + 1 2 3 4 5 6 7 SELECT a + b FROM t1 GROUP BY b; ERROR 42000: 'test.t1.a' isn't in GROUP BY SELECT (SELECT t1_outer.a FROM t1 AS t1_inner GROUP BY b LIMIT 1) FROM t1 AS t1_outer; (SELECT t1_outer.a FROM t1 AS t1_inner GROUP BY b LIMIT 1) 1 2 3 4 5 6 SELECT 1 FROM t1 as t1_outer GROUP BY a HAVING (SELECT t1_outer.a FROM t1 AS t1_inner GROUP BY b LIMIT 1); 1 1 1 1 1 1 1 SELECT (SELECT t1_outer.a FROM t1 AS t1_inner LIMIT 1) FROM t1 AS t1_outer GROUP BY t1_outer.b; ERROR 42000: 'test.t1_outer.a' isn't in GROUP BY SELECT 1 FROM t1 as t1_outer GROUP BY a HAVING (SELECT t1_outer.b FROM t1 AS t1_inner LIMIT 1); ERROR 42S22: Unknown column 'test.t1_outer.b' in 'field list' SELECT (SELECT SUM(t1_inner.a) FROM t1 AS t1_inner LIMIT 1) FROM t1 AS t1_outer GROUP BY t1_outer.b; (SELECT SUM(t1_inner.a) FROM t1 AS t1_inner LIMIT 1) 21 21 21 SELECT (SELECT SUM(t1_inner.a) FROM t1 AS t1_inner GROUP BY t1_inner.b LIMIT 1) FROM t1 AS t1_outer; (SELECT SUM(t1_inner.a) FROM t1 AS t1_inner GROUP BY t1_inner.b LIMIT 1) 3 3 3 3 3 3 SELECT (SELECT SUM(t1_outer.a) FROM t1 AS t1_inner LIMIT 1) FROM t1 AS t1_outer GROUP BY t1_outer.b; ERROR 42000: 'test.t1_outer.a' isn't in GROUP BY SELECT 1 FROM t1 as t1_outer WHERE (SELECT t1_outer.b FROM t1 AS t1_inner GROUP BY t1_inner.b LIMIT 1); 1 1 1 1 1 1 1 SELECT b FROM t1 GROUP BY b HAVING CEILING(b) > 0; b 1 2 3 SELECT 1 FROM t1 GROUP BY b HAVING b = 2 OR b = 3 OR SUM(a) > 12; 1 1 1 SELECT 1 FROM t1 GROUP BY b HAVING ROW (b,b) = ROW (1,1); 1 1 SELECT 1 FROM t1 GROUP BY b HAVING a = 2; ERROR 42S22: Unknown column 'a' in 'having clause' SELECT 1 FROM t1 GROUP BY SUM(b); ERROR HY000: Invalid use of group function SELECT b FROM t1 AS t1_outer GROUP BY a HAVING t1_outer.a IN (SELECT SUM(t1_inner.b)+t1_outer.b FROM t1 AS t1_inner GROUP BY t1_inner.a HAVING SUM(t1_inner.b)+t1_outer.b > 5); ERROR 42000: 'test.t1_outer.b' isn't in GROUP BY DROP TABLE t1; SET SQL_MODE = ''; SET SQL_MODE = 'ONLY_FULL_GROUP_BY'; create table t1(f1 int, f2 int); select * from t1 group by f1; ERROR 42000: 'test.t1.f2' isn't in GROUP BY select * from t1 group by f2; ERROR 42000: 'test.t1.f1' isn't in GROUP BY select * from t1 group by f1, f2; f1 f2 select t1.f1,t.* from t1, t1 t group by 1; ERROR 42000: 'test.t.f1' isn't in GROUP BY drop table t1; SET SQL_MODE = ''; CREATE TABLE t1( id INT AUTO_INCREMENT PRIMARY KEY, c1 INT NOT NULL, c2 INT NOT NULL, UNIQUE KEY (c2,c1)); INSERT INTO t1(c1,c2) VALUES (5,1), (4,1), (3,5), (2,3), (1,3); SELECT * FROM t1 ORDER BY c1; id c1 c2 5 1 3 4 2 3 3 3 5 2 4 1 1 5 1 SELECT * FROM t1 GROUP BY id ORDER BY c1; id c1 c2 5 1 3 4 2 3 3 3 5 2 4 1 1 5 1 SELECT * FROM t1 GROUP BY id ORDER BY id DESC; id c1 c2 5 1 3 4 2 3 3 3 5 2 4 1 1 5 1 SELECT * FROM t1 GROUP BY c2 ,c1, id ORDER BY c2, c1; id c1 c2 2 4 1 1 5 1 5 1 3 4 2 3 3 3 5 SELECT * FROM t1 GROUP BY c2, c1, id ORDER BY c2 DESC, c1; id c1 c2 3 3 5 5 1 3 4 2 3 2 4 1 1 5 1 SELECT * FROM t1 GROUP BY c2, c1, id ORDER BY c2 DESC, c1 DESC; id c1 c2 3 3 5 4 2 3 5 1 3 1 5 1 2 4 1 SELECT * FROM t1 GROUP BY c2 ORDER BY c2, c1; id c1 c2 1 5 1 4 2 3 3 3 5 SELECT * FROM t1 GROUP BY c2 ORDER BY c2 DESC, c1; id c1 c2 3 3 5 4 2 3 1 5 1 SELECT * FROM t1 GROUP BY c2 ORDER BY c2 DESC, c1 DESC; id c1 c2 3 3 5 4 2 3 1 5 1 DROP TABLE t1; # # Bug#27219: Aggregate functions in ORDER BY. # SET @save_sql_mode=@@sql_mode; SET @@sql_mode='ONLY_FULL_GROUP_BY'; CREATE TABLE t1 (a INT, b INT, c INT DEFAULT 0); INSERT INTO t1 (a, b) VALUES (3,3), (2,2), (3,3), (2,2), (3,3), (4,4); CREATE TABLE t2 SELECT * FROM t1; SELECT 1 FROM t1 ORDER BY COUNT(*); 1 1 SELECT 1 FROM t1 ORDER BY COUNT(*) + 1; 1 1 SELECT 1 FROM t1 ORDER BY COUNT(*) + a; ERROR 42000: Mixing of GROUP columns (MIN(),MAX(),COUNT(),...) with no GROUP columns is illegal if there is no GROUP BY clause SELECT 1 FROM t1 ORDER BY COUNT(*), 1; 1 1 SELECT 1 FROM t1 ORDER BY COUNT(*), a; ERROR 42000: Mixing of GROUP columns (MIN(),MAX(),COUNT(),...) with no GROUP columns is illegal if there is no GROUP BY clause SELECT 1 FROM t1 ORDER BY SUM(a); 1 1 SELECT 1 FROM t1 ORDER BY SUM(a + 1); 1 1 SELECT 1 FROM t1 ORDER BY SUM(a) + 1; 1 1 SELECT 1 FROM t1 ORDER BY SUM(a), b; ERROR 42000: Mixing of GROUP columns (MIN(),MAX(),COUNT(),...) with no GROUP columns is illegal if there is no GROUP BY clause SELECT a FROM t1 ORDER BY COUNT(b); ERROR 42000: Mixing of GROUP columns (MIN(),MAX(),COUNT(),...) with no GROUP columns is illegal if there is no GROUP BY clause SELECT t1.a FROM t1 ORDER BY (SELECT SUM(t2.a) FROM t2); a 3 2 3 2 3 4 SELECT t1.a FROM t1 ORDER BY (SELECT SUM(t2.a), t2.a FROM t2); ERROR 42000: Mixing of GROUP columns (MIN(),MAX(),COUNT(),...) with no GROUP columns is illegal if there is no GROUP BY clause SELECT t1.a FROM t1 ORDER BY (SELECT SUM(t2.a) FROM t2 ORDER BY t2.a); ERROR 42000: Mixing of GROUP columns (MIN(),MAX(),COUNT(),...) with no GROUP columns is illegal if there is no GROUP BY clause SELECT t1.a FROM t1 ORDER BY (SELECT t2.a FROM t2 ORDER BY SUM(t2.b) LIMIT 1); ERROR 42000: Mixing of GROUP columns (MIN(),MAX(),COUNT(),...) with no GROUP columns is illegal if there is no GROUP BY clause SELECT t1.a FROM t1 WHERE t1.a = (SELECT t2.a FROM t2 ORDER BY SUM(t2.b) LIMIT 1); ERROR 42000: Mixing of GROUP columns (MIN(),MAX(),COUNT(),...) with no GROUP columns is illegal if there is no GROUP BY clause SELECT t1.a FROM t1 GROUP BY t1.a HAVING t1.a = (SELECT t2.a FROM t2 ORDER BY SUM(t2.a) LIMIT 1); ERROR 42000: Mixing of GROUP columns (MIN(),MAX(),COUNT(),...) with no GROUP columns is illegal if there is no GROUP BY clause SELECT t1.a FROM t1 GROUP BY t1.a HAVING t1.a IN (SELECT t2.a FROM t2 ORDER BY SUM(t1.b)); a 2 3 4 SELECT t1.a FROM t1 GROUP BY t1.a HAVING t1.a IN (SELECT t2.a FROM t2 ORDER BY t2.a, SUM(t2.b)); ERROR 42000: Mixing of GROUP columns (MIN(),MAX(),COUNT(),...) with no GROUP columns is illegal if there is no GROUP BY clause SELECT t1.a FROM t1 GROUP BY t1.a HAVING t1.a > ANY (SELECT t2.a FROM t2 ORDER BY t2.a, SUM(t2.b)); ERROR 42000: Mixing of GROUP columns (MIN(),MAX(),COUNT(),...) with no GROUP columns is illegal if there is no GROUP BY clause SELECT t1.a FROM t1 WHERE t1.a = (SELECT t2.a FROM t2 ORDER BY SUM(t1.b)); ERROR 42000: Mixing of GROUP columns (MIN(),MAX(),COUNT(),...) with no GROUP columns is illegal if there is no GROUP BY clause SELECT 1 FROM t1 GROUP BY t1.a HAVING (SELECT AVG(SUM(t1.b) + 1) FROM t2 ORDER BY SUM(t2.a) LIMIT 1); 1 1 1 1 SELECT 1 FROM t1 GROUP BY t1.a HAVING (SELECT AVG(SUM(t1.b) + t2.b) FROM t2 ORDER BY SUM(t2.a) LIMIT 1); 1 1 1 1 SELECT 1 FROM t1 GROUP BY t1.a HAVING (SELECT AVG(t1.b + t2.b) FROM t2 ORDER BY SUM(t2.a) LIMIT 1); 1 1 1 1 SELECT 1 FROM t1 GROUP BY t1.a HAVING (SELECT AVG(SUM(t1.b) + 1) FROM t2 ORDER BY t2.a LIMIT 1); ERROR 42000: Mixing of GROUP columns (MIN(),MAX(),COUNT(),...) with no GROUP columns is illegal if there is no GROUP BY clause SELECT 1 FROM t1 GROUP BY t1.a HAVING (SELECT AVG(SUM(t1.b) + t2.b) FROM t2 ORDER BY t2.a LIMIT 1); ERROR 42000: Mixing of GROUP columns (MIN(),MAX(),COUNT(),...) with no GROUP columns is illegal if there is no GROUP BY clause SELECT 1 FROM t1 GROUP BY t1.a HAVING (SELECT AVG(t1.b + t2.b) FROM t2 ORDER BY t2.a LIMIT 1); ERROR 42000: Mixing of GROUP columns (MIN(),MAX(),COUNT(),...) with no GROUP columns is illegal if there is no GROUP BY clause SELECT t1.a FROM t1 WHERE t1.a = (SELECT t2.a FROM t2 GROUP BY t2.a ORDER BY SUM(t2.b), SUM(t1.b) LIMIT 1); a 4 SELECT t1.a, SUM(t1.b) FROM t1 WHERE t1.a = (SELECT SUM(t2.b) FROM t2 GROUP BY t2.a ORDER BY SUM(t2.b), SUM(t1.b) LIMIT 1) GROUP BY t1.a; a SUM(t1.b) 4 4 SELECT t1.a, SUM(t1.b) FROM t1 WHERE t1.a = (SELECT SUM(t2.b) FROM t2 ORDER BY SUM(t2.b) + SUM(t1.b) LIMIT 1) GROUP BY t1.a; a SUM(t1.b) SELECT t1.a, SUM(t1.b) FROM t1 WHERE t1.a = (SELECT SUM(t2.b) FROM t2 ORDER BY SUM(t2.b + t1.a) LIMIT 1) GROUP BY t1.a; a SUM(t1.b) SELECT t1.a FROM t1 GROUP BY t1.a HAVING (1, 1) = (SELECT SUM(t1.a), t1.a FROM t2 LIMIT 1); a select avg ( (select (select sum(outr.a + innr.a) from t1 as innr limit 1) as tt from t1 as outr order by outr.a limit 1)) from t1 as most_outer; avg ( (select (select sum(outr.a + innr.a) from t1 as innr limit 1) as tt from t1 as outr order by outr.a limit 1)) 29.0000 select avg ( (select ( (select sum(outr.a + innr.a) from t1 as innr limit 1)) as tt from t1 as outr order by count(outr.a) limit 1)) as tt from t1 as most_outer; ERROR 42000: Mixing of GROUP columns (MIN(),MAX(),COUNT(),...) with no GROUP columns is illegal if there is no GROUP BY clause select (select sum(outr.a + t1.a) from t1 limit 1) as tt from t1 as outr order by outr.a; tt 29 29 35 35 35 41 SET sql_mode=@save_sql_mode; DROP TABLE t1, t2; # # BUG#38072: Wrong result: HAVING not observed in a query with aggregate # CREATE TABLE t1 ( pk int(11) NOT NULL AUTO_INCREMENT, int_nokey int(11) NOT NULL, int_key int(11) NOT NULL, varchar_key varchar(1) NOT NULL, varchar_nokey varchar(1) NOT NULL, PRIMARY KEY (pk), KEY int_key (int_key), KEY varchar_key (varchar_key) ); INSERT INTO t1 VALUES (1,5,5, 'h','h'), (2,1,1, '{','{'), (3,1,1, 'z','z'), (4,8,8, 'x','x'), (5,7,7, 'o','o'), (6,3,3, 'p','p'), (7,9,9, 'c','c'), (8,0,0, 'k','k'), (9,6,6, 't','t'), (10,0,0,'c','c'); explain SELECT COUNT(varchar_key) AS X FROM t1 WHERE pk = 8 having 'foo'='bar'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Impossible HAVING SELECT COUNT(varchar_key) AS X FROM t1 WHERE pk = 8 having 'foo'='bar'; X drop table t1; End of 5.0 tests CREATE TABLE t1 (a INT, b INT, PRIMARY KEY (a), KEY i2(a,b)); INSERT INTO t1 VALUES (1,1),(2,2),(3,3),(4,4),(5,5),(6,6),(7,7),(8,8); INSERT INTO t1 SELECT a + 8,b FROM t1; INSERT INTO t1 SELECT a + 16,b FROM t1; INSERT INTO t1 SELECT a + 32,b FROM t1; INSERT INTO t1 SELECT a + 64,b FROM t1; INSERT INTO t1 SELECT a + 128,b FROM t1 limit 16; ANALYZE TABLE t1; Table Op Msg_type Msg_text test.t1 analyze status OK EXPLAIN SELECT a FROM t1 WHERE a < 2; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range PRIMARY,i2 PRIMARY 4 NULL 1 Using where; Using index EXPLAIN SELECT a FROM t1 WHERE a < 2 ORDER BY a; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range PRIMARY,i2 PRIMARY 4 NULL 1 Using where; Using index EXPLAIN SELECT a FROM t1 WHERE a < 2 GROUP BY a; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range PRIMARY,i2 PRIMARY 4 NULL 1 Using where; Using index EXPLAIN SELECT a FROM t1 IGNORE INDEX (PRIMARY,i2); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ALL NULL NULL NULL NULL 144 EXPLAIN SELECT a FROM t1 IGNORE INDEX FOR JOIN (PRIMARY,i2); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ALL NULL NULL NULL NULL 144 EXPLAIN SELECT a FROM t1 IGNORE INDEX FOR GROUP BY (PRIMARY,i2) GROUP BY a; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 index NULL PRIMARY 4 NULL 144 Using index EXPLAIN SELECT a FROM t1 IGNORE INDEX FOR ORDER BY (PRIMARY,i2) ORDER BY a; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 index NULL PRIMARY 4 NULL 144 Using index SELECT a FROM t1 IGNORE INDEX FOR ORDER BY (PRIMARY,i2) ORDER BY a; a 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 EXPLAIN SELECT a FROM t1 IGNORE INDEX FOR ORDER BY (PRIMARY) IGNORE INDEX FOR GROUP BY (i2) GROUP BY a; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 index NULL PRIMARY 4 NULL 144 Using index EXPLAIN SELECT a FROM t1 IGNORE INDEX (PRIMARY) IGNORE INDEX FOR ORDER BY (i2); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 index NULL i2 9 NULL 144 Using index EXPLAIN SELECT a FROM t1 FORCE INDEX (i2); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 index NULL i2 9 NULL 144 Using index EXPLAIN SELECT a FROM t1 USE INDEX (); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ALL NULL NULL NULL NULL 144 EXPLAIN SELECT a FROM t1 USE INDEX () USE INDEX (i2); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ALL NULL NULL NULL NULL 144 EXPLAIN SELECT a FROM t1 FORCE INDEX (PRIMARY) IGNORE INDEX FOR GROUP BY (i2) IGNORE INDEX FOR ORDER BY (i2) USE INDEX (i2); ERROR HY000: Incorrect usage of USE INDEX and FORCE INDEX EXPLAIN SELECT a FROM t1 USE INDEX (i2) USE INDEX (); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 index NULL i2 9 NULL 144 Using index EXPLAIN SELECT a FROM t1 FORCE INDEX (); ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ')' at line 1 EXPLAIN SELECT a FROM t1 IGNORE INDEX (); ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ')' at line 1 EXPLAIN SELECT a FROM t1 USE INDEX FOR JOIN (i2) USE INDEX FOR GROUP BY (i2) GROUP BY a; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 # NULL i2 # NULL # # EXPLAIN SELECT a FROM t1 FORCE INDEX FOR JOIN (i2) FORCE INDEX FOR GROUP BY (i2) GROUP BY a; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range NULL i2 4 NULL 145 Using index for group-by EXPLAIN SELECT a FROM t1 USE INDEX () IGNORE INDEX (i2); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ALL NULL NULL NULL NULL 144 EXPLAIN SELECT a FROM t1 IGNORE INDEX (i2) USE INDEX (); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ALL NULL NULL NULL NULL 144 EXPLAIN SELECT a FROM t1 USE INDEX FOR GROUP BY (i2) USE INDEX FOR ORDER BY (i2) USE INDEX FOR JOIN (i2); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 index NULL i2 9 NULL 144 Using index EXPLAIN SELECT a FROM t1 USE INDEX FOR JOIN (i2) USE INDEX FOR JOIN (i2) USE INDEX FOR JOIN (i2,i2); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 index NULL i2 9 NULL 144 Using index EXPLAIN SELECT 1 FROM t1 WHERE a IN (SELECT a FROM t1 USE INDEX (i2) IGNORE INDEX (i2)); id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 index NULL PRIMARY 4 NULL 144 Using where; Using index 2 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL 144 Using where CREATE TABLE t2 (a INT, b INT, KEY(a)); INSERT INTO t2 VALUES (1, 1), (2, 2), (3,3), (4,4); EXPLAIN SELECT a, SUM(b) FROM t2 GROUP BY a LIMIT 2; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t2 index NULL a 5 NULL 2 EXPLAIN SELECT a, SUM(b) FROM t2 IGNORE INDEX (a) GROUP BY a LIMIT 2; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t2 ALL NULL NULL NULL NULL 4 Using temporary; Using filesort EXPLAIN SELECT 1 FROM t2 WHERE a IN (SELECT a FROM t1 USE INDEX (i2) IGNORE INDEX (i2)); id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t2 index NULL a 5 NULL 4 Using where; Using index 2 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL 144 Using where SHOW VARIABLES LIKE 'old'; Variable_name Value old OFF SET @@old = off; ERROR HY000: Variable 'old' is a read only variable DROP TABLE t1, t2; CREATE TABLE t1( a INT, b INT NOT NULL, c INT NOT NULL, d INT, UNIQUE KEY (c,b) ); INSERT INTO t1 VALUES (1,1,1,50), (1,2,3,40), (2,1,3,4); CREATE TABLE t2( a INT, b INT, UNIQUE KEY(a,b) ); INSERT INTO t2 VALUES (NULL, NULL), (NULL, NULL), (NULL, 1), (1, NULL), (1, 1), (1,2); EXPLAIN SELECT c,b,d FROM t1 GROUP BY c,b,d; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ALL NULL NULL NULL NULL 3 Using filesort SELECT c,b,d FROM t1 GROUP BY c,b,d; c b d 1 1 50 3 1 4 3 2 40 EXPLAIN SELECT c,b,d FROM t1 GROUP BY c,b,d ORDER BY NULL; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ALL NULL NULL NULL NULL 3 SELECT c,b,d FROM t1 GROUP BY c,b,d ORDER BY NULL; c b d 1 1 50 3 2 40 3 1 4 EXPLAIN SELECT c,b,d FROM t1 ORDER BY c,b,d; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ALL NULL NULL NULL NULL 3 Using filesort SELECT c,b,d FROM t1 ORDER BY c,b,d; c b d 1 1 50 3 1 4 3 2 40 EXPLAIN SELECT c,b,d FROM t1 GROUP BY c,b; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ALL NULL NULL NULL NULL 3 Using filesort SELECT c,b,d FROM t1 GROUP BY c,b; c b d 1 1 50 3 1 4 3 2 40 EXPLAIN SELECT c,b FROM t1 GROUP BY c,b; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 index NULL c 8 NULL 3 Using index SELECT c,b FROM t1 GROUP BY c,b; c b 1 1 3 1 3 2 EXPLAIN SELECT a,b from t2 ORDER BY a,b; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t2 index NULL a 10 NULL 6 Using index SELECT a,b from t2 ORDER BY a,b; a b NULL NULL NULL NULL NULL 1 1 NULL 1 1 1 2 EXPLAIN SELECT a,b from t2 GROUP BY a,b; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t2 index NULL a 10 NULL 6 Using index SELECT a,b from t2 GROUP BY a,b; a b NULL NULL NULL 1 1 NULL 1 1 1 2 EXPLAIN SELECT a from t2 GROUP BY a; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t2 index NULL a 10 NULL 6 Using index SELECT a from t2 GROUP BY a; a NULL 1 EXPLAIN SELECT b from t2 GROUP BY b; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t2 index NULL a 10 NULL 6 Using index; Using temporary; Using filesort SELECT b from t2 GROUP BY b; b NULL 1 2 DROP TABLE t1; DROP TABLE t2; CREATE TABLE t1 ( a INT, b INT ); SELECT b c, (SELECT a FROM t1 WHERE b = c) FROM t1; c (SELECT a FROM t1 WHERE b = c) SELECT b c, (SELECT a FROM t1 WHERE b = c) FROM t1 HAVING b = 10; c (SELECT a FROM t1 WHERE b = c) SELECT MAX(b) c, (SELECT a FROM t1 WHERE b = c) FROM t1 HAVING b = 10; ERROR 42S22: Reference 'c' not supported (reference to group function) SET @old_sql_mode = @@sql_mode; SET @@sql_mode='ONLY_FULL_GROUP_BY'; SELECT b c, (SELECT a FROM t1 WHERE b = c) FROM t1; c (SELECT a FROM t1 WHERE b = c) SELECT b c, (SELECT a FROM t1 WHERE b = c) FROM t1 HAVING b = 10; ERROR 42000: non-grouping field 'b' is used in HAVING clause SELECT MAX(b) c, (SELECT a FROM t1 WHERE b = c) FROM t1 HAVING b = 10; ERROR 42S22: Reference 'c' not supported (reference to group function) INSERT INTO t1 VALUES (1, 1); SELECT b c, (SELECT a FROM t1 WHERE b = c) FROM t1; c (SELECT a FROM t1 WHERE b = c) 1 1 INSERT INTO t1 VALUES (2, 1); SELECT b c, (SELECT a FROM t1 WHERE b = c) FROM t1; ERROR 21000: Subquery returns more than 1 row DROP TABLE t1; SET @@sql_mode = @old_sql_mode; SET @old_sql_mode = @@sql_mode; SET @@sql_mode='ONLY_FULL_GROUP_BY'; CREATE TABLE t1(i INT); INSERT INTO t1 VALUES (1), (10); SELECT COUNT(i) FROM t1; COUNT(i) 2 SELECT COUNT(i) FROM t1 WHERE i > 1; COUNT(i) 1 DROP TABLE t1; SET @@sql_mode = @old_sql_mode;