func_group.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

XXX	NULL	MIN	NULL	NULL
WWW	1	LED	NULL	NULL
select * from t2;
a1	a2	a3	a4
TKF	Seattle	WA	AME
LCC	Los Angeles	CA	TWU
DEN	Denver	CO	BDL
SDC	San Diego	CA	TWU
NOL	New Orleans	LA	GTM
LAK	Los Angeles	CA	TWU
AAA	AAA	AA	AME
explain 
select min(a1) from t1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
select min(a1) from t1;
min(a1)
AME
explain 
select max(a4) from t1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
select max(a4) from t1;
max(a4)
0.1
explain 
select min(a5), max(a5) from t1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
select min(a5), max(a5) from t1;
min(a5)	max(a5)
1942-02-19	1977-09-23
explain 
select min(a3) from t1 where a2 = 2;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
select min(a3) from t1 where a2 = 2;
min(a3)
CHI
explain 
select min(a1), max(a1) from t1 where a4 = 0.080;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
select min(a1), max(a1) from t1 where a4 = 0.080;
min(a1)	max(a1)
BDL	TWU
explain 
select min(t1.a5), max(t2.a3) from t1, t2;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
select min(t1.a5), max(t2.a3) from t1, t2;
min(t1.a5)	max(t2.a3)
1942-02-19	WA
explain 
select min(t1.a3), max(t2.a2) from t1, t2 where t1.a2 = 0 and t2.a3 = 'CA';
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
select min(t1.a3), max(t2.a2) from t1, t2 where t1.a2 = 0 and t2.a3 = 'CA';
min(t1.a3)	max(t2.a2)
DEN	San Diego
explain 
select min(a1) from t1 where a1 > 'KKK';
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
select min(a1) from t1 where a1 > 'KKK';
min(a1)
PLS
explain 
select min(a1) from t1 where a1 >= 'KKK';
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
select min(a1) from t1 where a1 >= 'KKK';
min(a1)
KKK
explain 
select max(a3) from t1 where a2 = 2 and a3 < 'SEA';
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
select max(a3) from t1 where a2 = 2 and a3 < 'SEA';
max(a3)
MIN
explain 
select max(a5) from t1 where a5 < date'1970-01-01';
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
select max(a5) from t1 where a5 < date'1970-01-01';
max(a5)
1969-10-05
explain 
select max(a3) from t1 where a2 is null;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
select max(a3) from t1 where a2 is null;
max(a3)
MIN
explain 
select max(a3) from t1 where a2 = 0 and a3 between 'K' and 'Q';
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
select max(a3) from t1 where a2 = 0 and a3 between 'K' and 'Q';
max(a3)
LAX
explain
select min(a1), max(a1) from t1 where a1 between 'A' and 'P';
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
select min(a1), max(a1) from t1 where a1 between 'A' and 'P';
min(a1)	max(a1)
AME	KKK
explain 
select max(a3) from t1 where a3 < 'SEA' and a2 = 2 and a3 <= 'MIN';
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
select max(a3) from t1 where a3 < 'SEA' and a2 = 2 and a3 <= 'MIN';
max(a3)
MIN
explain 
select max(a3) from t1 where a3 = 'MIN' and a2 = 2;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
select max(a3) from t1 where a3 = 'MIN' and a2 = 2;
max(a3)
MIN
explain 
select max(a3) from t1 where a3 = 'DEN' and a2 = 2;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No matching min/max row
select max(a3) from t1 where a3 = 'DEN' and a2 = 2;
max(a3)
NULL
explain
select max(t1.a3), min(t2.a2) from t1, t2 where t1.a2 = 2 and t1.a3 < 'MIN' and t2.a3 = 'CA';
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
select max(t1.a3), min(t2.a2) from t1, t2 where t1.a2 = 2 and t1.a3 < 'MIN' and t2.a3 = 'CA';
max(t1.a3)	min(t2.a2)
CHI	Los Angeles
explain
select max(a3) from t1 where a2 is null and a2 = 2;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
select max(a3) from t1 where a2 is null and a2 = 2;
max(a3)
NULL
explain
select max(a2) from t1 where a2 >= 1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
select max(a2) from t1 where a2 >= 1;
max(a2)
3
explain
select min(a3) from t1 where a2 = 2 and a3 < 'SEA';
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
select min(a3) from t1 where a2 = 2 and a3 < 'SEA';
min(a3)
CHI
explain
select min(a3) from t1 where a2 = 4;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No matching min/max row
select min(a3) from t1 where a2 = 4;
min(a3)
NULL
explain
select min(a3) from t1 where a2 = 2 and a3 > 'SEA';
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No matching min/max row
select min(a3) from t1 where a2 = 2 and a3 > 'SEA';
min(a3)
NULL
explain
select (min(a4)+max(a4))/2 from t1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
select (min(a4)+max(a4))/2 from t1;
(min(a4)+max(a4))/2
0.085
explain
select min(a3) from t1 where 2 = a2;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
select min(a3) from t1 where 2 = a2;
min(a3)
CHI
explain
select max(a3) from t1 where a2 = 2 and 'SEA' > a3;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
select max(a3) from t1 where a2 = 2 and 'SEA' > a3;
max(a3)
MIN
explain
select max(a3) from t1 where a2 = 2 and 'SEA' < a3;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No matching min/max row
select max(a3) from t1 where a2 = 2 and 'SEA' < a3;
max(a3)
NULL
explain
select min(a3) from t1 where a2 = 2 and a3 >= 'CHI';
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
select min(a3) from t1 where a2 = 2 and a3 >= 'CHI';
min(a3)
CHI
explain
select min(a3) from t1 where a2 = 2 and a3 >= 'CHI' and a3 < 'SEA';
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
select min(a3) from t1 where a2 = 2 and a3 >= 'CHI' and a3 < 'SEA';
min(a3)
CHI
explain
select min(a3) from t1 where a2 = 2 and a3 >= 'CHI' and a3 = 'MIN';
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
select min(a3) from t1 where a2 = 2 and a3 >= 'CHI' and a3 = 'MIN';
min(a3)
MIN
explain
select min(a3) from t1 where a2 = 2 and a3 >= 'SEA' and a3 = 'MIN';
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
select min(a3) from t1 where a2 = 2 and a3 >= 'SEA' and a3 = 'MIN';
min(a3)
NULL
explain
select min(t1.a1), min(t2.a4) from t1,t2 where t1.a1 < 'KKK' and t2.a4 < 'KKK';
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
select min(t1.a1), min(t2.a4) from t1,t2 where t1.a1 < 'KKK' and t2.a4 < 'KKK';
min(t1.a1)	min(t2.a4)
AME	AME
explain 
select min(a1) from t1 where a1 > 'KKK' or a1 < 'XXX';
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	index	PRIMARY	PRIMARY	3	NULL	15	Using where; Using index
explain 
select min(a1) from t1 where a1 != 'KKK';
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	index	PRIMARY	PRIMARY	3	NULL	15	Using where; Using index
explain
select max(a3) from t1 where a2 < 2 and a3 < 'SEA';
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	k1	k1	3	NULL	6	Using where; Using index
explain
select max(t1.a3), min(t2.a2) from t1, t2 where t1.a2 = 2 and t1.a3 < 'MIN' and t2.a3 > 'CA';
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	k1	k1	7	NULL	1	Using where; Using index
1	SIMPLE	t2	range	k1	k1	3	NULL	4	Using where; Using index
explain
select min(a4 - 0.01) from t1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	index	NULL	k2	12	NULL	15	Using index
explain
select max(a4 + 0.01) from t1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	index	NULL	k2	12	NULL	15	Using index
explain
select min(a3) from t1 where (a2 +1 ) is null;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	index	NULL	k1	7	NULL	15	Using where; Using index
explain
select min(a3) from t1 where (a2 + 1) = 2;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	index	NULL	k1	7	NULL	15	Using where; Using index
explain
select min(a3) from t1 where 2 = (a2 + 1);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	index	NULL	k1	7	NULL	15	Using where; Using index
explain
select min(a2) from t1 where a2 < 2 * a2 - 8;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	index	NULL	k1	7	NULL	15	Using where; Using index
explain
select min(a1) from t1  where a1 between a3 and 'KKK';
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	ALL	PRIMARY	NULL	NULL	NULL	15	Using where
explain
select min(a4) from t1  where (a4 + 0.01) between 0.07 and 0.08;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	index	NULL	k2	12	NULL	15	Using where; Using index
explain
select concat(min(t1.a1),min(t2.a4)) from t1, t2 where t2.a4 <> 'AME';
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	range	k2	k2	4	NULL	6	Using where; Using index
1	SIMPLE	t1	index	NULL	PRIMARY	3	NULL	15	Using index
drop table t1, t2;
create table t1 (USR_ID integer not null, MAX_REQ integer not null, constraint PK_SEA_USER primary key (USR_ID)) engine=InnoDB;
insert into t1 values (1, 3);
select count(*) + MAX_REQ - MAX_REQ + MAX_REQ - MAX_REQ + MAX_REQ - MAX_REQ + MAX_REQ - MAX_REQ + MAX_REQ - MAX_REQ from t1 group by MAX_REQ;
count(*) + MAX_REQ - MAX_REQ + MAX_REQ - MAX_REQ + MAX_REQ - MAX_REQ + MAX_REQ - MAX_REQ + MAX_REQ - MAX_REQ
1
select Case When Count(*) < MAX_REQ Then 1 Else 0 End from t1 where t1.USR_ID = 1 group by MAX_REQ;
Case When Count(*) < MAX_REQ Then 1 Else 0 End
1
drop table t1;
create table t1 (a char(10));
insert into t1 values ('a'),('b'),('c');
select coercibility(max(a)) from t1;
coercibility(max(a))
2
drop table t1;
create table t1 (a char character set latin2);
insert into t1 values ('a'),('b');
select charset(max(a)), coercibility(max(a)),
charset(min(a)), coercibility(min(a)) from t1;
charset(max(a))	coercibility(max(a))	charset(min(a))	coercibility(min(a))
latin2	2	latin2	2
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `a` char(1) character set latin2 default NULL
) ENGINE=MyISAM DEFAULT CHARSET=latin1
create table t2 select max(a),min(a) from t1;
show create table t2;
Table	Create Table
t2	CREATE TABLE `t2` (
  `max(a)` char(1) character set latin2 default NULL,
  `min(a)` char(1) character set latin2 default NULL
) ENGINE=MyISAM DEFAULT CHARSET=latin1
drop table t2;
create table t2 select concat(a) from t1;
show create table t2;
Table	Create Table
t2	CREATE TABLE `t2` (
  `concat(a)` varchar(1) character set latin2 default NULL
) ENGINE=MyISAM DEFAULT CHARSET=latin1
drop table t2,t1;
create table t1 (a int);
insert into t1 values (1);
select max(a) as b from t1 having b=1;
b
1
select a from t1 having a=1;
a
1
drop table t1;
create table t1 (a int);
select variance(2) from t1;
variance(2)
NULL
select stddev(2) from t1;
stddev(2)
NULL
drop table t1;
create table t1 (a int);
insert into t1 values (1),(2);
prepare stmt1 from 'SELECT COUNT(*) FROM t1';
execute stmt1;
COUNT(*)
2
execute stmt1;
COUNT(*)
2
execute stmt1;
COUNT(*)
2
deallocate prepare stmt1;
drop table t1;
create table t1 (a int, primary key(a));
insert into t1 values (1),(2);
prepare stmt1 from 'SELECT max(a) FROM t1';