union.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

6
SELECT SQL_CALC_FOUND_ROWS * FROM t1 UNION SELECT * FROM t2 LIMIT 2,2;
a
3
4
select found_rows();
found_rows()
6
SELECT SQL_CALC_FOUND_ROWS * FROM t1 limit 2,2 UNION SELECT * FROM t2;
a
3
4
5
select found_rows();
found_rows()
5
SELECT * FROM t1 UNION SELECT * FROM t2 ORDER BY a desc LIMIT 1;
a
5
(SELECT * FROM t1 ORDER by a) UNION ALL (SELECT * FROM t2 ORDER BY a) ORDER BY A desc LIMIT 4;
a
5
4
3
3
(SELECT * FROM t1) UNION all (SELECT SQL_CALC_FOUND_ROWS * FROM t2) LIMIT 1;
ERROR 42000: Incorrect usage/placement of 'SQL_CALC_FOUND_ROWS'
create temporary table t1 select a from t1 union select a from t2;
drop temporary table t1;
create table t1 select a from t1 union select a from t2;
ERROR HY000: You can't specify target table 't1' for update in FROM clause
select a from t1 union select a from t2 order by t2.a;
ERROR 42S22: Unknown column 't2.a' in 'order clause'
drop table t1,t2;
select length(version()) > 1 as `*` UNION select 2;
*
1
2
create table t1 (a int);
insert into t1 values (0), (3), (1), (2);
explain (select * from t1) union (select * from t1) order by a;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	
2	UNION	t1	ALL	NULL	NULL	NULL	NULL	4	
NULL	UNION RESULT	<union1,2>	ALL	NULL	NULL	NULL	NULL	NULL	Using filesort
drop table t1;
CREATE TABLE t1 (  id int(3) unsigned default '0') ENGINE=MyISAM;
INSERT INTO t1 (id) VALUES("1");
CREATE TABLE t2 ( id int(3) unsigned default '0',  id_master int(5) default '0',  text1 varchar(5) default NULL,  text2 varchar(5) default NULL) ENGINE=MyISAM;
INSERT INTO t2 (id, id_master, text1, text2) VALUES("1", "1",
"foo1", "bar1");
INSERT INTO t2 (id, id_master, text1, text2) VALUES("2", "1",
"foo2", "bar2");
INSERT INTO t2 (id, id_master, text1, text2) VALUES("3", "1", NULL,
"bar3");
INSERT INTO t2 (id, id_master, text1, text2) VALUES("4", "1",
"foo4", "bar4");
SELECT 1 AS id_master, 1 AS id, NULL AS text1, 'ABCDE' AS text2 UNION SELECT id_master, t2.id, text1, text2 FROM t1 LEFT JOIN t2 ON t1.id = t2.id_master;
id_master	id	text1	text2
1	1	NULL	ABCDE
1	1	foo1	bar1
1	2	foo2	bar2
1	3	NULL	bar3
1	4	foo4	bar4
SELECT 1 AS id_master, 1 AS id, 'ABCDE' AS text1, 'ABCDE' AS text2 UNION SELECT id_master, t2.id, text1, text2 FROM t1 LEFT JOIN t2 ON t1.id = t2.id_master;
id_master	id	text1	text2
1	1	ABCDE	ABCDE
1	1	foo1	bar1
1	2	foo2	bar2
1	3	NULL	bar3
1	4	foo4	bar4
drop table if exists t1,t2;
create table t1 (a int not null primary key auto_increment, b int, key(b));
create table t2 (a int not null primary key auto_increment, b int);
insert into t1 (b) values (1),(2),(2),(3);
insert into t2 (b) values (10),(11),(12),(13);
explain extended (select * from t1 where a=1) union (select * from t2 where a=1);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	t1	const	PRIMARY	PRIMARY	4	const	1	
2	UNION	t2	const	PRIMARY	PRIMARY	4	const	1	
NULL	UNION RESULT	<union1,2>	ALL	NULL	NULL	NULL	NULL	NULL	
Warnings:
Note	1003	(select `test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b` from `test`.`t1` where (`test`.`t1`.`a` = 1)) union (select `test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b` from `test`.`t2` where (`test`.`t2`.`a` = 1))
(select * from t1 where a=5) union (select * from t2 where a=1);
a	b
1	10
(select * from t1 where a=5 and a=6) union (select * from t2 where a=1);
a	b
1	10
(select t1.a,t1.b from t1,t2 where t1.a=5) union (select * from t2 where a=1);
a	b
1	10
(select * from t1 where a=1) union (select t1.a,t2.a from t1,t2 where t1.a=t2.a);
a	b
1	1
2	2
3	3
4	4
explain (select * from t1 where a=1 and b=10) union (select straight_join t1.a,t2.a from t1,t2 where t1.a=t2.a);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
2	UNION	t1	index	PRIMARY	PRIMARY	4	NULL	4	Using index
2	UNION	t2	index	PRIMARY	PRIMARY	4	NULL	3	Using where; Using index
NULL	UNION RESULT	<union1,2>	ALL	NULL	NULL	NULL	NULL	NULL	
explain (select * from t1 where a=1) union (select * from t1 where b=1);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	t1	const	PRIMARY	PRIMARY	4	const	1	
2	UNION	t1	ref	b	b	5	const	1	Using where
NULL	UNION RESULT	<union1,2>	ALL	NULL	NULL	NULL	NULL	NULL	
drop table t1,t2;
create table t1 (   id int not null auto_increment, primary key (id)   ,user_name text );
create table t2 (    id int not null auto_increment, primary key (id)   ,group_name text );
create table t3 (    id int not null auto_increment, primary key (id)   ,user_id int   ,index user_idx (user_id)   ,foreign key (user_id) references users(id)   ,group_id int   ,index group_idx (group_id)   ,foreign key (group_id) references groups(id) );
insert into t1 (user_name) values ('Tester');
insert into t2 (group_name) values ('Group A');
insert into t2 (group_name) values ('Group B');
insert into t3 (user_id, group_id) values (1,1);
select 1 'is_in_group', a.user_name, c.group_name, b.id from t1 a, t3 b, t2 c where a.id = b.user_id and b.group_id = c.id UNION  select 0 'is_in_group', a.user_name, c.group_name, null from t1 a, t2 c;
is_in_group	user_name	group_name	id
1	Tester	Group A	1
0	Tester	Group A	NULL
0	Tester	Group B	NULL
drop table t1, t2, t3;
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 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 union SELECT 0, 0;
pla_id	matintnum
100	a
101	a
102	a
103	b
104	b
105	c
0	0
drop table t1, t2;
create table t1 SELECT "a" as a UNION select "aa" as a;
select * from t1;
a
a
aa
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `a` varchar(2) NOT NULL default ''
) ENGINE=MyISAM DEFAULT CHARSET=latin1
drop table t1;
create table t1 SELECT 12 as a UNION select "aa" as a;
select * from t1;
a
12
aa
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `a` varbinary(20) NOT NULL default ''
) ENGINE=MyISAM DEFAULT CHARSET=latin1
drop table t1;
create table t1 SELECT 12 as a UNION select 12.2 as a;
select * from t1;
a
12.0
12.2
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `a` decimal(3,1) NOT NULL default '0.0'
) ENGINE=MyISAM DEFAULT CHARSET=latin1
drop table t1;
create table t2 (it1 tinyint, it2 tinyint not null, i int not null, ib bigint, f float, d double, y year, da date, dt datetime, sc char(10), sv varchar(10), b blob, tx text);
insert into t2 values (NULL, 1, 3, 4, 1.5, 2.5, 1972, '1972-10-22', '1972-10-22 11:50', 'testc', 'testv', 'tetetetetest', 'teeeeeeeeeeeest');
create table t1 SELECT it2 from t2 UNION select it1 from t2;
select * from t1;
it2
1
NULL
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `it2` tinyint(4) default NULL
) ENGINE=MyISAM DEFAULT CHARSET=latin1
drop table t1;
create table t1 SELECT it2 from t2 UNION select i from t2;
select * from t1;
it2
1
3
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `it2` int(11) NOT NULL default '0'
) ENGINE=MyISAM DEFAULT CHARSET=latin1
drop table t1;
create table t1 SELECT i from t2 UNION select f from t2;
select * from t1;
i
3
1.5
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `i` double default NULL
) ENGINE=MyISAM DEFAULT CHARSET=latin1
drop table t1;
create table t1 SELECT f from t2 UNION select d from t2;
select * from t1;
f
1.5
2.5
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `f` double default NULL
) ENGINE=MyISAM DEFAULT CHARSET=latin1
drop table t1;
create table t1 SELECT ib from t2 UNION select f from t2;
select * from t1;
ib
4
1.5
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `ib` double default NULL
) ENGINE=MyISAM DEFAULT CHARSET=latin1
drop table t1;
create table t1 SELECT ib from t2 UNION select d from t2;
select * from t1;
ib
4
2.5
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `ib` double default NULL
) ENGINE=MyISAM DEFAULT CHARSET=latin1
drop table t1;
create table t1 SELECT f from t2 UNION select y from t2;
select * from t1;
f
1.5
1972
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `f` float default NULL
) ENGINE=MyISAM DEFAULT CHARSET=latin1
drop table t1;
create table t1 SELECT f from t2 UNION select da from t2;
select * from t1;
f
1.5
1972-10-22
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `f` varbinary(24) default NULL
) ENGINE=MyISAM DEFAULT CHARSET=latin1
drop table t1;
create table t1 SELECT y from t2 UNION select da from t2;
select * from t1;
y
1972
1972-10-22
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `y` varbinary(10) default NULL
) ENGINE=MyISAM DEFAULT CHARSET=latin1
drop table t1;
create table t1 SELECT y from t2 UNION select dt from t2;
select * from t1;
y
1972
1972-10-22 11:50:00
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `y` varbinary(19) default NULL
) ENGINE=MyISAM DEFAULT CHARSET=latin1
drop table t1;
create table t1 SELECT da from t2 UNION select dt from t2;
select * from t1;
da
1972-10-22 00:00:00
1972-10-22 11:50:00
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `da` datetime default NULL
) ENGINE=MyISAM DEFAULT CHARSET=latin1
drop table t1;
create table t1 SELECT dt from t2 UNION select sc from t2;
select * from t1;
dt
1972-10-22 11:50:00
testc
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `dt` varbinary(19) default NULL
) ENGINE=MyISAM DEFAULT CHARSET=latin1
drop table t1;
create table t1 SELECT dt from t2 UNION select sv from t2;
select * from t1;
dt
1972-10-22 11:50:00
testv
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `dt` varbinary(19) default NULL
) ENGINE=MyISAM DEFAULT CHARSET=latin1
drop table t1;
create table t1 SELECT sc from t2 UNION select sv from t2;
select * from t1;
sc
testc
testv
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `sc` varchar(10) default NULL
) ENGINE=MyISAM DEFAULT CHARSET=latin1
drop table t1;
create table t1 SELECT dt from t2 UNION select b from t2;
select * from t1;
dt
1972-10-22 11:50:00
tetetetetest
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `dt` longblob
) ENGINE=MyISAM DEFAULT CHARSET=latin1
drop table t1;
create table t1 SELECT sv from t2 UNION select b from t2;
select * from t1;
sv
testv
tetetetetest
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `sv` longblob
) ENGINE=MyISAM DEFAULT CHARSET=latin1
drop table t1;
create table t1 SELECT i from t2 UNION select d from t2 UNION select b from t2;
select * from t1;
i
3
2.5
tetetetetest
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `i` longblob
) ENGINE=MyISAM DEFAULT CHARSET=latin1
drop table t1;
create table t1 SELECT sv from t2 UNION select tx from t2;
select * from t1;
sv
testv
teeeeeeeeeeeest
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `sv` longtext
) ENGINE=MyISAM DEFAULT CHARSET=latin1
drop table t1;
create table t1 SELECT b from t2 UNION select tx from t2;
select * from t1;
b
tetetetetest
teeeeeeeeeeeest
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `b` longblob
) ENGINE=MyISAM DEFAULT CHARSET=latin1
drop table t1,t2;
create table t1 select 1 union select -1;
select * from t1;
1
1
-1
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `1` bigint(20) NOT NULL default '0'
) ENGINE=MyISAM DEFAULT CHARSET=latin1
drop table t1;
create table t1 select _latin1"test" union select _latin2"testt" ;
ERROR HY000: Illegal mix of collations (latin1_swedish_ci,COERCIBLE) and (latin2_general_ci,COERCIBLE) for operation 'UNION'
create table t1 select _latin2"test" union select _latin2"testt" ;
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `test` varchar(5) character set latin2 NOT NULL default ''