# Initialize --disable_warnings drop table if exists t1,t2,t3; --enable_warnings select * from (select 2 from DUAL) b; -- error 1054 SELECT 1 as a FROM (SELECT 1 UNION SELECT a) b; -- error 1054 SELECT 1 as a FROM (SELECT a UNION SELECT 1) b; CREATE TABLE t1 (a int not null, b char (10) not null); insert into t1 values(1,'a'),(2,'b'),(3,'c'),(3,'c'); CREATE TABLE t2 (a int not null, b char (10) not null); insert into t2 values (3,'c'),(4,'d'),(5,'f'),(6,'e'); select t1.a,t3.y from t1,(select a as y from t2 where b='c') as t3 where t1.a = t3.y; select t1.a,t3.a from t1,(select * from t2 where b='c') as t3 where t1.a = t3.a; CREATE TABLE t3 (a int not null, b char (10) not null); insert into t3 values (3,'f'),(4,'y'),(5,'z'),(6,'c'); select t1.a,t4.y from t1,(select t2.a as y from t2,(select t3.b from t3 where t3.a>3) as t5 where t2.b=t5.b) as t4 where t1.a = t4.y; --error 1054 SELECT a FROM (SELECT 1 FROM (SELECT 1) a HAVING a=1) b; --error 1052 SELECT a,b as a FROM (SELECT '1' as a,'2' as b) b HAVING a=1; SELECT a,2 as a FROM (SELECT '1' as a) b HAVING a=2; SELECT a,2 as a FROM (SELECT '1' as a) b HAVING a=1; --error 1054 SELECT 1 FROM (SELECT 1) a WHERE a=2; --error 1054 SELECT (SELECT 1) as a FROM (SELECT 1 FROM t1 HAVING a=1) as a; select * from t1 as x1, (select * from t1) as x2; explain select * from t1 as x1, (select * from t1) as x2; drop table if exists t2,t3; select * from (select 1) as a; select a from (select 1 as a) as b; select 1 from (select 1) as a; select * from (select * from t1 union select * from t1) a; select * from (select * from t1 union all select * from t1) a; select * from (select * from t1 union all select * from t1 limit 2) a; explain select * from (select * from t1 union select * from t1) a; explain select * from (select * from t1 union all select * from t1) a; CREATE TABLE t2 (a int not null); insert into t2 values(1); select * from (select * from t1 where t1.a=(select a from t2 where t2.a=t1.a)) a; select * from (select * from t1 where t1.a=(select t2.a from t2 where t2.a=t1.a) union select t1.a, t1.b from t1) a; explain select * from (select * from t1,t2 where t1.a=t2.a) t1; drop table t1, t2; create table t1(a int not null, t char(8), index(a)); disable_query_log; let $1 = 10000; while ($1) { eval insert into t1 values ($1,'$1'); dec $1; } enable_query_log; SELECT * FROM (SELECT * FROM t1) as b ORDER BY a ASC LIMIT 0,20; explain select count(*) from t1 as tt1, (select * from t1) as tt2; drop table t1; SELECT * FROM (SELECT (SELECT * FROM (SELECT 1 as a) as a )) as b; select * from (select 1 as a) b left join (select 2 as a) c using(a); --error 1054 SELECT * FROM (SELECT 1 UNION SELECT a) b; --error 1054 SELECT 1 as a FROM (SELECT a UNION SELECT 1) b; --error 1054 SELECT 1 as a FROM (SELECT 1 UNION SELECT a) b; --error 1054 select 1 from (select 2) a order by 0; # # Test of explain (bug #251) # create table t1 (id int); insert into t1 values (1),(2),(3); describe select * from (select * from t1 group by id) bar; drop table t1; # # test->used_keys test for derived tables # create table t1 (mat_id MEDIUMINT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY, matintnum CHAR(6) NOT NULL, test MEDIUMINT UNSIGNED NULL); create table t2 (mat_id MEDIUMINT UNSIGNED NOT NULL, pla_id MEDIUMINT UNSIGNED NOT NULL); insert into t1 values (NULL, 'a', 1), (NULL, 'b', 2), (NULL, 'c', 3), (NULL, 'd', 4), (NULL, 'e', 5), (NULL, 'f', 6), (NULL, 'g', 7), (NULL, 'h', 8), (NULL, 'i', 9); insert into t2 values (1, 100), (1, 101), (1, 102), (2, 100), (2, 103), (2, 104), (3, 101), (3, 102), (3, 105); SELECT STRAIGHT_JOIN d.pla_id, m2.mat_id FROM t1 m2 INNER JOIN (SELECT mp.pla_id, MIN(m1.matintnum) AS matintnum FROM t2 mp INNER JOIN t1 m1 ON mp.mat_id=m1.mat_id GROUP BY mp.pla_id) d ON d.matintnum=m2.matintnum; SELECT STRAIGHT_JOIN d.pla_id, m2.test FROM t1 m2 INNER JOIN (SELECT mp.pla_id, MIN(m1.matintnum) AS matintnum FROM t2 mp INNER JOIN t1 m1 ON mp.mat_id=m1.mat_id GROUP BY mp.pla_id) d ON d.matintnum=m2.matintnum; explain SELECT STRAIGHT_JOIN d.pla_id, m2.mat_id FROM t1 m2 INNER JOIN (SELECT mp.pla_id, MIN(m1.matintnum) AS matintnum FROM t2 mp INNER JOIN t1 m1 ON mp.mat_id=m1.mat_id GROUP BY mp.pla_id) d ON d.matintnum=m2.matintnum; explain SELECT STRAIGHT_JOIN d.pla_id, m2.test FROM t1 m2 INNER JOIN (SELECT mp.pla_id, MIN(m1.matintnum) AS matintnum FROM t2 mp INNER JOIN t1 m1 ON mp.mat_id=m1.mat_id GROUP BY mp.pla_id) d ON d.matintnum=m2.matintnum; drop table t1,t2; # # derived table reference # SELECT a.x FROM (SELECT 1 AS x) AS a HAVING a.x = 1; # # Test for select if database is not selected. # # Connect without a database create table t1 select 1 as a; connect (con1,localhost,mysqltest_1,,*NO-ONE*,$MASTER_MYPORT,master.sock); connection con1; --error 1046 select 2 as a from (select * from t1) b; use test; select 2 as a from (select * from t1) b; drop table t1; --error 1064 select mail_id, if(folder.f_description!='', folder.f_description, folder.f_name) as folder_name, date, address_id, phrase, address, subject from folder, (select mail.mail_id as mail_id, date_format(mail.h_date, '%b %e, %Y %h:%i') as date, mail.folder_id, sender.address_id as address_id, sender.phrase as phrase, sender.address as address, mail.h_subject as subject from mail left join mxa as mxa_sender on mail.mail_id=mxa_sender.mail_id and mxa_sender.type='from' left join address as sender on mxa_sender.address_id=sender.address_id mxa as mxa_recipient, address as recipient, where 1 and mail.mail_id=mxa_recipient.mail_id and mxa_recipient.address_id=recipient.address_id and mxa_recipient.type='to' and match(sender.phrase, sender.address, sender.comment) against ('jeremy' in boolean mode) and match(recipient.phrase, recipient.address, recipient.comment) against ('monty' in boolean mode) order by mail.h_date desc limit 0, 25 ) as query where query.folder_id=folder.folder_id; # # UPDATE/DELETE/INSERT of derived tables # create table t1 (a int); insert into t1 values (1),(2),(3); -- error 1287 update (select * from t1) as t1 set a = 5; -- error 1064 delete from (select * from t1); -- error 1064 insert into (select * from t1) values (5); drop table t1; # # deived tables with subquery inside all by one table # create table t1 (E1 INTEGER UNSIGNED NOT NULL, E2 INTEGER UNSIGNED NOT NULL, E3 INTEGER UNSIGNED NOT NULL, PRIMARY KEY(E1) ); insert into t1 VALUES(1,1,1), (2,2,1); select count(*) from t1 INNER JOIN (SELECT A.E1, A.E2, A.E3 FROM t1 AS A WHERE A.E3 = (SELECT MAX(B.E3) FROM t1 AS B WHERE A.E2 = B.E2)) AS THEMAX ON t1.E1 = THEMAX.E2 AND t1.E1 = t1.E2; explain select count(*) from t1 INNER JOIN (SELECT A.E1, A.E2, A.E3 FROM t1 AS A WHERE A.E3 = (SELECT MAX(B.E3) FROM t1 AS B WHERE A.E2 = B.E2)) AS THEMAX ON t1.E1 = THEMAX.E2 AND t1.E1 = t1.E2; drop table t1; create table t1 (a int); insert into t1 values (1),(2); select * from ( select * from t1 union select * from t1) a,(select * from t1 union select * from t1) b; explain select * from ( select * from t1 union select * from t1) a,(select * from t1 union select * from t1) b; drop table t1; # # multi-update & multi-delete with derived tables # CREATE TABLE `t1` ( `N` int(11) unsigned NOT NULL default '0', `M` tinyint(1) default '0', ) TYPE=MyISAM DEFAULT CHARSET=latin1; INSERT INTO `t1` (N, M) VALUES (1, 0),(1, 0),(1, 0),(2, 0),(2, 0),(3, 0); UPDATE `t1` AS P1 INNER JOIN (SELECT N FROM `t1` GROUP BY N HAVING Count(M) > 1) AS P2 ON P1.N = P2.N SET P1.M = 2; select * from t1; -- error 1287 UPDATE `t1` AS P1 INNER JOIN (SELECT N FROM `t1` GROUP BY N HAVING Count(M) > 1) AS P2 ON P1.N = P2.N SET P1.M = 2, P2.N = 2; -- error 1054 UPDATE `t1` AS P1 INNER JOIN (SELECT aaaa FROM `t1` GROUP BY N HAVING Count(M) > 1) AS P2 ON P1.N = P2.N SET P1.M = 2; delete P1.* from `t1` AS P1 INNER JOIN (SELECT N FROM `t1` GROUP BY N HAVING Count(M) > 1) AS P2 ON P1.N = P2.N; select * from t1; -- error 1287 delete P1.*,P2.* from `t1` AS P1 INNER JOIN (SELECT N FROM `t1` GROUP BY N HAVING Count(M) > 1) AS P2 ON P1.N = P2.N; -- error 1054 delete P1.* from `t1` AS P1 INNER JOIN (SELECT aaa FROM `t1` GROUP BY N HAVING Count(M) > 1) AS P2 ON P1.N = P2.N; drop table t1; # # correct lex->current_select # CREATE TABLE t1 ( OBJECTID int(11) NOT NULL default '0', SORTORDER int(11) NOT NULL auto_increment, KEY t1_SortIndex (SORTORDER), KEY t1_IdIndex (OBJECTID) ) TYPE=MyISAM DEFAULT CHARSET=latin1; CREATE TABLE t2 ( ID int(11) default NULL, PARID int(11) default NULL, UNIQUE KEY t2_ID_IDX (ID), KEY t2_PARID_IDX (PARID) ) engine=MyISAM DEFAULT CHARSET=latin1; INSERT INTO t2 VALUES (1000,0),(1001,0),(1002,0),(1003,0),(1008,1),(1009,1),(1010,1),(1011,1),(1016,2); CREATE TABLE t3 ( ID int(11) default NULL, DATA decimal(10,2) default NULL, UNIQUE KEY t3_ID_IDX (ID) ) engine=MyISAM DEFAULT CHARSET=latin1; INSERT INTO t3 VALUES (1000,0.00),(1001,0.25),(1002,0.50),(1003,0.75),(1008,1.00),(1009,1.25),(1010,1.50),(1011,1.75); select 497, TMP.ID, NULL from (select 497 as ID, MAX(t3.DATA) as DATA from t1 join t2 on (t1.ObjectID = t2.ID) join t3 on (t1.ObjectID = t3.ID) group by t2.ParID order by DATA DESC) as TMP; drop table t1, t2, t3; # # explain derived # CREATE TABLE t1 (name char(1) default NULL, val int(5) default NULL); INSERT INTO t1 VALUES ('a',1), ('a',2), ('a',2), ('a',2), ('a',3), ('a',6), ('a',7), ('a',11), ('a',11), ('a',12), ('a',13), ('a',13), ('a',20), ('b',2), ('b',3), ('b',4), ('b',5); SELECT s.name, AVG(s.val) AS median FROM (SELECT x.name, x.val FROM t1 x, t1 y WHERE x.name=y.name GROUP BY x.name, x.val HAVING SUM(y.val <= x.val) >= COUNT(*)/2 AND SUM(y.val >= x.val) >= COUNT(*)/2) AS s GROUP BY s.name; explain SELECT s.name, AVG(s.val) AS median FROM (SELECT x.name, x.val FROM t1 x, t1 y WHERE x.name=y.name GROUP BY x.name, x.val HAVING SUM(y.val <= x.val) >= COUNT(*)/2 AND SUM(y.val >= x.val) >= COUNT(*)/2) AS s GROUP BY s.name; drop table t1; # # "Using index" in explain # create table t2 (a int, b int, primary key (a)); insert into t2 values (1,7),(2,7); explain select a from t2 where a>1; explain select a from (select a from t2 where a>1) tt; drop table t2;