order_by.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

1	1	b
1	1	
1	0	b
1	0	
select count(*) from t1 where a < 5 and b > 0;
count(*)
9
select * from t1 where a < 5 and b > 0 order by a desc,b desc;
a	b	c
2	3	c
2	2	b
2	2	a
2	1	b
2	1	a
1	3	b
1	1	b
1	1	b
1	1	
explain select * from t1 where a between 1 and 3 and b <= 1 order by a desc, b desc;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	a	a	8	NULL	10	Using where; Using index
select * from t1 where a between 1 and 3 and b <= 1 order by a desc, b desc;
a	b	c
2	1	b
2	1	a
1	1	b
1	1	b
1	1	
1	0	b
1	0	
explain select * from t1 where a between 0 and 1 order by a desc, b desc;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	a	a	4	NULL	5	Using where; Using index
select * from t1 where a between 0 and 1 order by a desc, b desc;
a	b	c
1	3	b
1	1	b
1	1	b
1	1	
1	0	b
1	0	
drop table t1;
CREATE TABLE t1 (
gid int(10) unsigned NOT NULL auto_increment,
cid smallint(5) unsigned NOT NULL default '0',
PRIMARY KEY  (gid),
KEY component_id (cid)
) ENGINE=MyISAM;
INSERT INTO t1 VALUES (103853,108),(103867,108),(103962,108),(104505,108),(104619,108),(104620,108);
ALTER TABLE t1 add skr int(10) not null;
CREATE TABLE t2 (
gid int(10) unsigned NOT NULL default '0',
uid smallint(5) unsigned NOT NULL default '1',
sid tinyint(3) unsigned NOT NULL default '1',
PRIMARY KEY  (gid),
KEY uid (uid),
KEY status_id (sid)
) ENGINE=MyISAM;
INSERT INTO t2 VALUES (103853,250,5),(103867,27,5),(103962,27,5),(104505,117,5),(104619,75,5),(104620,15,5);
CREATE TABLE t3 (
uid smallint(6) NOT NULL auto_increment,
PRIMARY KEY  (uid)
) ENGINE=MyISAM;
INSERT INTO t3 VALUES (1),(15),(27),(75),(117),(250);
ALTER TABLE t3 add skr int(10) not null;
select t1.gid, t2.sid, t3.uid from t2, t1, t3 where t2.gid = t1.gid and t2.uid = t3.uid order by t3.uid, t1.gid;
gid	sid	uid
104620	5	15
103867	5	27
103962	5	27
104619	5	75
104505	5	117
103853	5	250
select t1.gid, t2.sid, t3.uid from t3, t2, t1 where t2.gid = t1.gid and t2.uid = t3.uid order by t3.uid, t1.gid;
gid	sid	uid
104620	5	15
103867	5	27
103962	5	27
104619	5	75
104505	5	117
103853	5	250
EXPLAIN select t1.gid, t2.sid, t3.uid from t3, t2, t1 where t2.gid = t1.gid and t2.uid = t3.uid order by t1.gid, t3.uid;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	index	PRIMARY	PRIMARY	4	NULL	6	Using index
1	SIMPLE	t2	eq_ref	PRIMARY,uid	PRIMARY	4	test.t1.gid	1	
1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	2	test.t2.uid	1	Using where; Using index
EXPLAIN SELECT t1.gid, t3.uid from t1, t3 where t1.gid = t3.uid order by t1.gid,t3.skr;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t3	ALL	PRIMARY	NULL	NULL	NULL	6	Using temporary; Using filesort
1	SIMPLE	t1	eq_ref	PRIMARY	PRIMARY	4	test.t3.uid	1	Using where; Using index
EXPLAIN SELECT t1.gid, t2.sid, t3.uid from t2, t1, t3 where t2.gid = t1.gid and t2.uid = t3.uid order by t3.uid, t1.gid;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	index	PRIMARY	PRIMARY	4	NULL	6	Using index; Using temporary; Using filesort
1	SIMPLE	t2	eq_ref	PRIMARY,uid	PRIMARY	4	test.t1.gid	1	
1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	2	test.t2.uid	1	Using where; Using index
EXPLAIN SELECT t1.gid, t3.uid from t1, t3 where t1.gid = t3.uid order by t3.skr,t1.gid;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t3	ALL	PRIMARY	NULL	NULL	NULL	6	Using temporary; Using filesort
1	SIMPLE	t1	eq_ref	PRIMARY	PRIMARY	4	test.t3.uid	1	Using where; Using index
EXPLAIN SELECT t1.gid, t3.uid from t1, t3 where t1.skr = t3.uid order by t1.gid,t3.skr;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	6	Using temporary; Using filesort
1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	2	test.t1.skr	1	Using where
drop table t1,t2,t3;
CREATE TABLE t1 (
`titre` char(80) NOT NULL default '',
`numeropost` mediumint(8) unsigned NOT NULL auto_increment,
`date` datetime NOT NULL default '0000-00-00 00:00:00',
`auteur` char(35) NOT NULL default '',
`icone` tinyint(2) unsigned NOT NULL default '0',
`lastauteur` char(35) NOT NULL default '',
`nbrep` smallint(6) unsigned NOT NULL default '0',
`dest` char(35) NOT NULL default '',
`lu` tinyint(1) unsigned NOT NULL default '0',
`vue` mediumint(8) unsigned NOT NULL default '0',
`ludest` tinyint(1) unsigned NOT NULL default '0',
`ouvert` tinyint(1) unsigned NOT NULL default '1',
PRIMARY KEY  (`numeropost`),
KEY `date` (`date`),
KEY `dest` (`dest`,`ludest`),
KEY `auteur` (`auteur`,`lu`),
KEY `auteur_2` (`auteur`,`date`),
KEY `dest_2` (`dest`,`date`)
) CHECKSUM=1;
CREATE TABLE t2 (
`numeropost` mediumint(8) unsigned NOT NULL default '0',
`pseudo` char(35) NOT NULL default '',
PRIMARY KEY  (`numeropost`,`pseudo`),
KEY `pseudo` (`pseudo`)
);
INSERT INTO t1 (titre,auteur,dest) VALUES ('test','joce','bug');
INSERT INTO t2 (numeropost,pseudo) VALUES (1,'joce'),(1,'bug');
SELECT titre,t1.numeropost,auteur,icone,nbrep,0,date,vue,ouvert,lastauteur,dest FROM t2 LEFT JOIN t1 USING(numeropost) WHERE t2.pseudo='joce' ORDER BY date DESC LIMIT 0,30;
titre	numeropost	auteur	icone	nbrep	0	date	vue	ouvert	lastauteur	dest
test	1	joce	0	0	0	0000-00-00 00:00:00	0	1		bug
SELECT titre,numeropost,auteur,icone,nbrep,0,date,vue,ouvert,lastauteur,dest FROM t2 LEFT JOIN t1 USING(numeropost) WHERE t2.pseudo='joce' ORDER BY date DESC LIMIT 0,30;
titre	numeropost	auteur	icone	nbrep	0	date	vue	ouvert	lastauteur	dest
test	1	joce	0	0	0	0000-00-00 00:00:00	0	1		bug
SELECT titre,t1.numeropost,auteur,icone,nbrep,'0',date,vue,ouvert,lastauteur,dest FROM t2 LEFT JOIN t1 USING(numeropost) WHERE t2.pseudo='joce' ORDER BY date DESC LIMIT 0,30;
titre	numeropost	auteur	icone	nbrep	0	date	vue	ouvert	lastauteur	dest
test	1	joce	0	0	0	0000-00-00 00:00:00	0	1		bug
SELECT titre,numeropost,auteur,icone,nbrep,'0',date,vue,ouvert,lastauteur,dest FROM t2 LEFT JOIN t1 USING(numeropost) WHERE t2.pseudo='joce' ORDER BY date DESC LIMIT 0,30;
titre	numeropost	auteur	icone	nbrep	0	date	vue	ouvert	lastauteur	dest
test	1	joce	0	0	0	0000-00-00 00:00:00	0	1		bug
drop table t1,t2;
CREATE TABLE t1 (a int, b int);
INSERT INTO t1 VALUES (1, 2);
INSERT INTO t1 VALUES (3, 4);
INSERT INTO t1 VALUES (5, NULL);
SELECT * FROM t1 ORDER BY b;
a	b
5	NULL
1	2
3	4
SELECT * FROM t1 ORDER BY b DESC;
a	b
3	4
1	2
5	NULL
SELECT * FROM t1 ORDER BY (a + b);
a	b
5	NULL
1	2
3	4
SELECT * FROM t1 ORDER BY (a + b) DESC;
a	b
3	4
1	2
5	NULL
DROP TABLE t1;
create table t1(id int not null auto_increment primary key, t char(12));
explain select id,t from t1 order by id;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	1000	Using filesort
explain select id,t from t1 force index (primary) order by id;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	index	NULL	PRIMARY	4	NULL	1000	
drop table t1;
CREATE TABLE t1 (
FieldKey varchar(36) NOT NULL default '',
LongVal bigint(20) default NULL,
StringVal mediumtext,
KEY FieldKey (FieldKey),
KEY LongField (FieldKey,LongVal),
KEY StringField (FieldKey,StringVal(32))
);
INSERT INTO t1 VALUES ('0',3,'0'),('0',2,'1'),('0',1,'2'),('1',2,'1'),('1',1,'3'), ('1',0,'2'),('2',3,'0'),('2',2,'1'),('2',1,'2'),('2',3,'0'),('2',2,'1'),('2',1,'2'),('3',2,'1'),('3',1,'2'),('3','3','3');
EXPLAIN SELECT * FROM t1 WHERE FieldKey = '1' ORDER BY LongVal;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	ref	FieldKey,LongField,StringField	LongField	38	const	3	Using where
SELECT * FROM t1 WHERE FieldKey = '1' ORDER BY LongVal;
FieldKey	LongVal	StringVal
1	0	2
1	1	3
1	2	1
EXPLAIN SELECT * FROM t1 WHERE FieldKey > '2' ORDER BY LongVal;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	FieldKey,LongField,StringField	FieldKey	38	NULL	4	Using where; Using filesort
SELECT * FROM t1 WHERE FieldKey > '2' ORDER BY LongVal;
FieldKey	LongVal	StringVal
3	1	2
3	2	1
3	3	3
EXPLAIN SELECT * FROM t1 WHERE FieldKey > '2' ORDER BY FieldKey, LongVal;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	FieldKey,LongField,StringField	LongField	38	NULL	4	Using where
SELECT * FROM t1 WHERE FieldKey > '2' ORDER BY FieldKey, LongVal;
FieldKey	LongVal	StringVal
3	1	2
3	2	1
3	3	3
DROP TABLE t1;
CREATE TABLE t1 (a INT, b INT);
SET @id=0;
UPDATE t1 SET a=0 ORDER BY (a=@id), b;
DROP TABLE t1;
CREATE TABLE t1 (  id smallint(6) unsigned NOT NULL default '0',  menu tinyint(4) NOT NULL default '0',  KEY id (id),  KEY menu (menu)) ENGINE=MyISAM;
INSERT INTO t1 VALUES (11384, 2),(11392, 2);
SELECT id FROM t1 WHERE id <11984 AND menu =2 ORDER BY id DESC LIMIT 1 ;
id
11392
drop table t1;
create table t1(a int, b int, index(b));
insert into t1 values (2, 1), (1, 1), (4, NULL), (3, NULL), (6, 2), (5, 2);
explain select * from t1 where b=1 or b is null order by a;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	ref_or_null	b	b	5	const	3	Using where; Using filesort
select * from t1 where b=1 or b is null order by a;
a	b
1	1
2	1
3	NULL
4	NULL
explain select * from t1 where b=2 or b is null order by a;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	ref_or_null	b	b	5	const	4	Using where; Using filesort
select * from t1 where b=2 or b is null order by a;
a	b
3	NULL
4	NULL
5	2
6	2
drop table t1;
create table t1 (a int not null auto_increment, b int not null, c int not null, d int not null,
key(a,b,d), key(c,b,a));
create table t2 like t1;
insert into t1 values (NULL, 1, 2, 0), (NULL, 2, 1, 1), (NULL, 3, 4, 2), (NULL, 4, 3, 3);
insert into t2 select null, b, c, d from t1;
insert into t1 select null, b, c, d from t2;
insert into t2 select null, b, c, d from t1;
insert into t1 select null, b, c, d from t2;
insert into t2 select null, b, c, d from t1;
insert into t1 select null, b, c, d from t2;
insert into t2 select null, b, c, d from t1;
insert into t1 select null, b, c, d from t2;
insert into t2 select null, b, c, d from t1;
insert into t1 select null, b, c, d from t2;
optimize table t1;
Table	Op	Msg_type	Msg_text
test.t1	optimize	status	OK
set @row=10;
insert into t1 select 1, b, c + (@row:=@row - 1) * 10, d - @row from t2 limit 10;
select * from t1 where a=1 and b in (1) order by c, b, a;
a	b	c	d
1	1	2	0
1	1	12	-1
1	1	52	-5
1	1	92	-9
select * from t1 where a=1 and b in (1);
a	b	c	d
1	1	92	-9
1	1	52	-5
1	1	12	-1
1	1	2	0
drop table t1, t2;
create table t1 (col1 int, col int);
create table t2 (col2 int, col int);
insert into t1 values (1,1),(2,2),(3,3);
insert into t2 values (1,3),(2,2),(3,1);
select t1.* , t2.col as t2_col from t1 left join t2 on (t1.col1=t2.col2)
order by col;
col1	col	t2_col
1	1	3
2	2	2
3	3	1
select col1 as col, col from t1 order by col;
ERROR 23000: Column 'col' in order clause is ambiguous
select t1.col as c1, t2.col as c2 from t1, t2 where t1.col1=t2.col2
order by col;
ERROR 23000: Column 'col' in order clause is ambiguous
select t1.col as c1, t2.col as c2 from t1, t2 where t1.col1=t2.col2
order by col;
ERROR 23000: Column 'col' in order clause is ambiguous
select col1 from t1, t2 where t1.col1=t2.col2 order by col;
ERROR 23000: Column 'col' in order clause is ambiguous
select t1.col as t1_col, t2.col2 from t1, t2 where t1.col1=t2.col2
order by col;
ERROR 23000: Column 'col' in order clause is ambiguous
select t1.col as t1_col, t2.col from t1, t2 where t1.col1=t2.col2
order by col;
t1_col	col
3	1
2	2
1	3
select col2 as c, col as c from t2 order by col;
c	c
3	1
2	2
1	3
select col2 as col, col as col2 from t2 order by col;
col	col2
1	3
2	2
3	1
select t2.col2, t2.col, t2.col from t2 order by col;
col2	col	col
3	1	1
2	2	2
1	3	3
select t2.col2 as col from t2 order by t2.col;
col
3
2
1
select t2.col2 as col, t2.col from t2 order by t2.col;
col	col
3	1
2	2
1	3
select t2.col2, t2.col, t2.col from t2 order by t2.col;
col2	col	col
3	1	1
2	2	2
1	3	3
drop table t1, t2;
create table t1 (a char(25));
insert into t1 set a = repeat('x', 20);
insert into t1 set a = concat(repeat('x', 19), 'z');
insert into t1 set a = concat(repeat('x', 19), 'ab');
insert into t1 set a = concat(repeat('x', 19), 'aa');
set max_sort_length=20;
select a from t1 order by a;
a
xxxxxxxxxxxxxxxxxxxab
xxxxxxxxxxxxxxxxxxxaa
xxxxxxxxxxxxxxxxxxxx
xxxxxxxxxxxxxxxxxxxz
drop table t1;
create table t1 (a int not null, b  int not null, c int not null);
insert t1 values (1,1,1),(1,1,2),(1,2,1);
select a, b from t1 group by a, b order by sum(c);
a	b
1	2
1	1
drop table t1;
create table t1 (
`sid` decimal(8,0) default null,
`wnid` varchar(11) not null default '',
key `wnid14` (`wnid`(4)),
key `wnid` (`wnid`)
) engine=myisam default charset=latin1;
insert into t1 (`sid`, `wnid`) values
('10100','01019000000'),('37986','01019000000'),('37987','01019010000'),
('39560','01019090000'),('37989','01019000000'),('37990','01019011000'),
('37991','01019011000'),('37992','01019019000'),('37993','01019030000'),
('37994','01019090000'),('475','02070000000'),('25253','02071100000'),
('25255','02071100000'),('25256','02071110000'),('25258','02071130000'),
('25259','02071190000'),('25260','02071200000'),('25261','02071210000'),
('25262','02071290000'),('25263','02071300000'),('25264','02071310000'),
('25265','02071310000'),('25266','02071320000'),('25267','02071320000'),
('25269','02071330000'),('25270','02071340000'),('25271','02071350000'),
('25272','02071360000'),('25273','02071370000'),('25281','02071391000'),
('25282','02071391000'),('25283','02071399000'),('25284','02071400000'),
('25285','02071410000'),('25286','02071410000'),('25287','02071420000'),
('25288','02071420000'),('25291','02071430000'),('25290','02071440000'),
('25292','02071450000'),('25293','02071460000'),('25294','02071470000'),
('25295','02071491000'),('25296','02071491000'),('25297','02071499000');
explain select * from t1 where wnid like '0101%' order by wnid;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	wnid14,wnid	wnid	13	NULL	10	Using where
select * from t1 where wnid like '0101%' order by wnid;
sid	wnid
10100	01019000000
37986	01019000000
37989	01019000000
37987	01019010000
37990	01019011000
37991	01019011000
37992	01019019000
37993	01019030000
39560	01019090000
37994	01019090000
drop table t1;
CREATE TABLE t1 (a int);
INSERT INTO t1 VALUES (2), (1), (1), (2), (1);
SELECT a FROM t1 ORDER BY a;
a
1
1
1
2
2
(SELECT a FROM t1) ORDER BY a;
a
1
1
1
2
2
DROP TABLE t1;