derived.result

这是linux下运行的mysql软件包,可用于linux 下安装 php + mysql + apach 的网络配置

2	DERIVED	mp	ALL	NULL	NULL	NULL	NULL	9	Using temporary; Using filesort
2	DERIVED	m1	eq_ref	PRIMARY	PRIMARY	3	test.mp.mat_id	1	
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;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	m2	ALL	NULL	NULL	NULL	NULL	9	
1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	6	Using where
2	DERIVED	mp	ALL	NULL	NULL	NULL	NULL	9	Using temporary; Using filesort
2	DERIVED	m1	eq_ref	PRIMARY	PRIMARY	3	test.mp.mat_id	1	
drop table t1,t2;
SELECT a.x FROM (SELECT 1 AS x) AS a HAVING a.x = 1;
x
1
create table t1 select 1 as a;
select 2 as a from (select * from t1) b;
ERROR 3D000: No database selected
use test;
select 2 as a from (select * from t1) b;
a
2
drop table t1;
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;
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 'mxa as mxa_recipient,   address as recipient, where 1     and mail.mail_id=mxa_r' at line 1
create table t1 (a int);
insert into t1 values (1),(2),(3);
update (select * from t1) as t1 set a = 5;
ERROR HY000: The target table t1 of the UPDATE is not updatable
delete from (select * from t1);
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 '(select * from t1)' at line 1
insert into  (select * from t1) values (5);
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 '(select * from t1) values (5)' at line 1
drop table t1;
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;
count(*)
2
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;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	2	
1	PRIMARY	t1	eq_ref	PRIMARY	PRIMARY	4	THEMAX.E2	1	Using where
2	DERIVED	A	ALL	NULL	NULL	NULL	NULL	2	Using where
3	DEPENDENT SUBQUERY	B	ALL	NULL	NULL	NULL	NULL	2	Using where
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;
a	a
1	1
2	1
1	2
2	2
explain select * from ( select * from t1 union select * from t1) a,(select * from t1 union select * from t1) b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	2	
1	PRIMARY	<derived4>	ALL	NULL	NULL	NULL	NULL	2	
4	DERIVED	t1	ALL	NULL	NULL	NULL	NULL	2	
5	UNION	t1	ALL	NULL	NULL	NULL	NULL	2	
NULL	UNION RESULT	<union4,5>	ALL	NULL	NULL	NULL	NULL	NULL	
2	DERIVED	t1	ALL	NULL	NULL	NULL	NULL	2	
3	UNION	t1	ALL	NULL	NULL	NULL	NULL	2	
NULL	UNION RESULT	<union2,3>	ALL	NULL	NULL	NULL	NULL	NULL	
drop table t1;
CREATE TABLE `t1` (
`N` int(11) unsigned NOT NULL default '0',
`M` tinyint(1) default '0'
) ENGINE=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;
N	M
1	2
1	2
1	2
2	2
2	2
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, P2.N = 2;
ERROR HY000: The target table P2 of the UPDATE is not updatable
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;
ERROR 42S22: Unknown column 'aaaa' in 'field list'
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;
N	M
3	0
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 HY000: The target table p2 of the DELETE is not updatable
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;
ERROR 42S22: Unknown column 'aaa' in 'field list'
drop table t1;
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)
) ENGINE=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;
497	ID	NULL
drop table t1, t2, t3;
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;
name	median
a	7.0000
b	3.5000
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;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	3	Using temporary; Using filesort
2	DERIVED	x	ALL	NULL	NULL	NULL	NULL	17	Using temporary; Using filesort
2	DERIVED	y	ALL	NULL	NULL	NULL	NULL	17	Using where
drop table t1;
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;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	index	PRIMARY	PRIMARY	4	NULL	2	Using where; Using index
explain select a from (select a from t2 where a>1) tt;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	<derived2>	system	NULL	NULL	NULL	NULL	1	
2	DERIVED	t2	index	PRIMARY	PRIMARY	4	NULL	2	Using where; Using index
drop table t2;
CREATE TABLE `t1` ( `itemid` int(11) NOT NULL default '0', `grpid` varchar(15) NOT NULL default '', `vendor` int(11) NOT NULL default '0', `date_` date NOT NULL default '0000-00-00', `price` decimal(12,2) NOT NULL default '0.00', PRIMARY KEY  (`itemid`,`grpid`,`vendor`,`date_`), KEY `itemid` (`itemid`,`vendor`), KEY `itemid_2` (`itemid`,`date_`));
insert into t1 values (128, 'rozn', 2, now(), 10),(128, 'rozn', 1, now(), 10);
SELECT MIN(price) min, MAX(price) max, AVG(price) avg FROM (SELECT SUBSTRING( MAX(concat(date_,";",price)), 12) price FROM t1 WHERE itemid=128 AND  grpid='rozn' GROUP BY itemid, grpid, vendor) lastprices;
min	max	avg
10.00	10.00	10
DROP TABLE t1;
create table t1 (a integer, b integer);
insert into t1 values (1,4), (2,2),(2,2), (4,1),(4,1),(4,1),(4,1);
select distinct sum(b) from t1 group by a;
sum(b)
4
select distinct sum(b) from (select a,b from t1) y group by a;
sum(b)
4
drop table t1;
CREATE TABLE t1 (a char(10), b char(10));
INSERT INTO t1 VALUES ('root','localhost'), ('root','%');
SELECT * FROM (SELECT (SELECT a.a FROM t1 AS a WHERE a.a = b.a) FROM t1 AS b) AS c;
ERROR 21000: Subquery returns more than 1 row
DROP TABLE t1;
create table t1(a int);
create table t2(a int);
create table t3(a int);
insert into t1 values(1),(1);
insert into t2 values(2),(2);
insert into t3 values(3),(3);
select * from t1 union distinct select * from t2 union all select * from t3;
a
1
2
3
3
select * from (select * from t1 union distinct select * from t2 union all select * from t3) X;
a
1
2
3
3
drop table t1, t2, t3;
create table t1 (a int);
create table t2 (a int);
select * from (select * from t1,t2) foo;
ERROR 42S21: Duplicate column name 'a'
drop table t1,t2;
create table t1 (ID int unsigned not null auto_increment,
DATA varchar(5) not null, primary key (ID));
create table t2 (ID int unsigned not null auto_increment,
DATA varchar(5) not null, FID int unsigned not null,
primary key (ID));
select A.* from (t1 inner join (select * from t2) as A on t1.ID = A.FID);
ID	DATA	FID
select t2.* from ((select * from t1) as A inner join t2 on A.ID = t2.FID);
ID	DATA	FID
select t2.* from (select * from t1) as A inner join t2 on A.ID = t2.FID;
ID	DATA	FID
drop table t1, t2;