group_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

drop table t1;
CREATE TABLE t1 (
`a` char(193) default NULL,
`b` char(63) default NULL
);
INSERT INTO t1 VALUES ('abc','def'),('hij','klm');
SELECT CONCAT(a, b) FROM t1 GROUP BY 1;
CONCAT(a, b)
abcdef
hijklm
SELECT CONCAT(a, b),count(*) FROM t1 GROUP BY 1;
CONCAT(a, b)	count(*)
abcdef	1
hijklm	1
SELECT CONCAT(a, b),count(distinct a) FROM t1 GROUP BY 1;
CONCAT(a, b)	count(distinct a)
abcdef	1
hijklm	1
SELECT 1 FROM t1 GROUP BY CONCAT(a, b);
1
1
1
INSERT INTO t1 values ('hij','klm');
SELECT CONCAT(a, b),count(*) FROM t1 GROUP BY 1;
CONCAT(a, b)	count(*)
abcdef	1
hijklm	2
DROP TABLE t1;
create table t1 (One int unsigned, Two int unsigned, Three int unsigned, Four int unsigned);
insert into t1 values (1,2,1,4),(1,2,2,4),(1,2,3,4),(1,2,4,4),(1,1,1,4),(1,1,2,4),(1,1,3,4),(1,1,4,4),(1,3,1,4),(1,3,2,4),(1,3,3,4),(1,3,4,4);
select One, Two, sum(Four) from t1 group by One,Two;
One	Two	sum(Four)
1	1	16
1	2	16
1	3	16
drop table t1;
create table t1 (id integer primary key not null auto_increment, gender char(1));
insert into t1 values (NULL, 'M'), (NULL, 'F'),(NULL, 'F'),(NULL, 'F'),(NULL, 'M');
create table t2 (user_id integer not null, date date);
insert into t2 values (1, '2002-06-09'),(2, '2002-06-09'),(1, '2002-06-09'),(3, '2002-06-09'),(4, '2002-06-09'),(4, '2002-06-09');
select u.gender as gender, count(distinct  u.id) as dist_count, (count(distinct u.id)/5*100) as percentage from t1 u, t2 l where l.user_id = u.id group by u.gender;
gender	dist_count	percentage
F	3	60.0000
M	1	20.0000
select u.gender as  gender, count(distinct  u.id) as dist_count, (count(distinct u.id)/5*100) as percentage from t1 u, t2 l where l.user_id = u.id group by u.gender  order by percentage;
gender	dist_count	percentage
M	1	20.0000
F	3	60.0000
drop table t1,t2;
CREATE TABLE t1 (ID1 int, ID2 int, ID int NOT NULL AUTO_INCREMENT,PRIMARY KEY(ID
));
insert into t1 values (1,244,NULL),(2,243,NULL),(134,223,NULL),(185,186,NULL);
select S.ID as xID, S.ID1 as xID1 from t1 as S left join t1 as yS  on S.ID1 between yS.ID1 and yS.ID2;
xID	xID1
1	1
2	2
2	2
3	134
3	134
3	134
4	185
4	185
4	185
4	185
select S.ID as xID, S.ID1 as xID1, repeat('*',count(distinct yS.ID)) as Level from t1 as S left join t1 as yS  on S.ID1 between yS.ID1 and yS.ID2 group by xID order by xID1;
xID	xID1	Level
1	1	*
2	2	**
3	134	***
4	185	****
drop table t1;
CREATE TABLE t1 (
pid int(11) unsigned NOT NULL default '0',
c1id int(11) unsigned default NULL,
c2id int(11) unsigned default NULL,
value int(11) unsigned NOT NULL default '0',
UNIQUE KEY pid2 (pid,c1id,c2id),
UNIQUE KEY pid (pid,value)
) ENGINE=MyISAM;
INSERT INTO t1 VALUES (1, 1, NULL, 1),(1, 2, NULL, 2),(1, NULL, 3, 3),(1, 4, NULL, 4),(1, 5, NULL, 5);
CREATE TABLE t2 (
id int(11) unsigned NOT NULL default '0',
active enum('Yes','No') NOT NULL default 'Yes',
PRIMARY KEY  (id)
) ENGINE=MyISAM;
INSERT INTO t2 VALUES (1, 'Yes'),(2, 'No'),(4, 'Yes'),(5, 'No');
CREATE TABLE t3 (
id int(11) unsigned NOT NULL default '0',
active enum('Yes','No') NOT NULL default 'Yes',
PRIMARY KEY  (id)
);
INSERT INTO t3 VALUES (3, 'Yes');
select * from t1 AS m LEFT JOIN t2 AS c1 ON m.c1id = 
c1.id AND c1.active = 'Yes' LEFT JOIN t3 AS c2 ON m.c2id = c2.id AND 
c2.active = 'Yes' WHERE m.pid=1  AND (c1.id IS NOT NULL OR c2.id IS NOT NULL);
pid	c1id	c2id	value	id	active	id	active
1	1	NULL	1	1	Yes	NULL	NULL
1	NULL	3	3	NULL	NULL	3	Yes
1	4	NULL	4	4	Yes	NULL	NULL
select max(value) from t1 AS m LEFT JOIN t2 AS c1 ON 
m.c1id = c1.id AND c1.active = 'Yes' LEFT JOIN t3 AS c2 ON m.c2id = 
c2.id AND c2.active = 'Yes' WHERE m.pid=1  AND (c1.id IS NOT NULL OR c2.id IS 
NOT NULL);
max(value)
4
drop table t1,t2,t3;
create table t1 (a blob null);
insert into t1 values (NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(""),(""),(""),("b");
select a,count(*) from t1 group by a;
a	count(*)
NULL	9
	3
b	1
set option sql_big_tables=1;
select a,count(*) from t1 group by a;
a	count(*)
NULL	9
	3
b	1
drop table t1;
create table t1 (a int not null, b int not null);
insert into t1 values (1,1),(1,2),(3,1),(3,2),(2,2),(2,1);
create table t2 (a int not null, b int not null, key(a));
insert into t2 values (1,3),(3,1),(2,2),(1,1);
select t1.a,t2.b from t1,t2 where t1.a=t2.a group by t1.a,t2.b;
a	b
1	1
1	3
2	2
3	1
select t1.a,t2.b from t1,t2 where t1.a=t2.a group by t1.a,t2.b ORDER BY NULL;
a	b
1	3
3	1
2	2
1	1
explain select t1.a,t2.b from t1,t2 where t1.a=t2.a group by t1.a,t2.b;
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	t2	ALL	a	NULL	NULL	NULL	3	Using where
explain select t1.a,t2.b from t1,t2 where t1.a=t2.a group by t1.a,t2.b 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 temporary
1	SIMPLE	t2	ALL	a	NULL	NULL	NULL	3	Using where
drop table t1,t2;
create table t1 (a int, b int);
insert into t1 values (1, 4),(10, 40),(1, 4),(10, 43),(1, 4),(10, 41),(1, 4),(10, 43),(1, 4);
select a, MAX(b), INTERVAL (MAX(b), 1,3,10,30,39,40,50,60,100,1000) from t1 group by a;
a	MAX(b)	INTERVAL (MAX(b), 1,3,10,30,39,40,50,60,100,1000)
1	4	2
10	43	6
select a, MAX(b), CASE MAX(b) when 4 then 4 when 43 then 43 else 0 end from t1 group by a;
a	MAX(b)	CASE MAX(b) when 4 then 4 when 43 then 43 else 0 end
1	4	4
10	43	43
select a, MAX(b), FIELD(MAX(b), '43', '4', '5') from t1 group by a;
a	MAX(b)	FIELD(MAX(b), '43', '4', '5')
1	4	2
10	43	1
select a, MAX(b), CONCAT_WS(MAX(b), '43', '4', '5') from t1 group by a;
a	MAX(b)	CONCAT_WS(MAX(b), '43', '4', '5')
1	4	434445
10	43	43434435
select a, MAX(b), ELT(MAX(b), 'a', 'b', 'c', 'd', 'e', 'f') from t1 group by a;
a	MAX(b)	ELT(MAX(b), 'a', 'b', 'c', 'd', 'e', 'f')
1	4	d
10	43	NULL
select a, MAX(b), MAKE_SET(MAX(b), 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h') from t1 group by a;
a	MAX(b)	MAKE_SET(MAX(b), 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h')
1	4	c
10	43	a,b,d,f
drop table t1;
create table t1 (id int not null, qty int not null);
insert into t1 values (1,2),(1,3),(2,4),(2,5);
select id, sum(qty) as sqty, count(qty) as cqty from t1 group by id having sum(qty)>2 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 (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;