drop table if exists t1,t2;
set @sav_dpi= @@div_precision_increment;
set div_precision_increment= 5;
show variables like 'div_precision_increment';
Variable_name	Value
div_precision_increment	5
create table t1 (grp int, a bigint unsigned, c char(10) not null);
insert into t1 values (1,1,"a");
insert into t1 values (2,2,"b");
insert into t1 values (2,3,"c");
insert into t1 values (3,4,"E");
insert into t1 values (3,5,"C");
insert into t1 values (3,6,"D");
select a,c,sum(a) from t1 group by a;
a	c	sum(a)
1	a	1
2	b	2
3	c	3
4	E	4
5	C	5
6	D	6
select a,c,sum(a) from t1 where a > 10 group by a;
a	c	sum(a)
select sum(a) from t1 where a > 10;
sum(a)
NULL
select a from t1 order by rand(10);
a
2
6
1
3
5
4
select distinct a from t1 order by rand(10);
a
2
6
1
3
5
4
select count(distinct a),count(distinct grp) from t1;
count(distinct a)	count(distinct grp)
6	3
insert into t1 values (null,null,'');
select count(distinct a),count(distinct grp) from t1;
count(distinct a)	count(distinct grp)
6	3
select sum(all a),count(all a),avg(all a),std(all a),variance(all a),bit_or(all a),bit_and(all a),min(all a),max(all a),min(all c),max(all c) from t1;
sum(all a)	count(all a)	avg(all a)	std(all a)	variance(all a)	bit_or(all a)	bit_and(all a)	min(all a)	max(all a)	min(all c)	max(all c)
21	6	3.50000	1.70783	2.91667	7	0	1	6		E
select grp, sum(a),count(a),avg(a),std(a),variance(a),bit_or(a),bit_and(a),min(a),max(a),min(c),max(c) from t1 group by grp;
grp	sum(a)	count(a)	avg(a)	std(a)	variance(a)	bit_or(a)	bit_and(a)	min(a)	max(a)	min(c)	max(c)
NULL	NULL	0	NULL	NULL	NULL	0	18446744073709551615	NULL	NULL		
1	1	1	1.00000	0.00000	0.00000	1	1	1	1	a	a
2	5	2	2.50000	0.50000	0.25000	3	2	2	3	b	c
3	15	3	5.00000	0.81650	0.66667	7	4	4	6	C	E
select grp, sum(a)+count(a)+avg(a)+std(a)+variance(a)+bit_or(a)+bit_and(a)+min(a)+max(a)+min(c)+max(c) as sum from t1 group by grp;
grp	sum
NULL	NULL
1	7
2	20.25
3	45.483163247594
create table t2 (grp int, a bigint unsigned, c char(10));
insert into t2 select grp,max(a)+max(grp),max(c) from t1 group by grp;
replace into t2 select grp, a, c from t1 limit 2,1;
select * from t2;
grp	a	c
NULL	NULL	
1	2	a
2	5	c
3	9	E
2	3	c
drop table t1,t2;
CREATE TABLE t1 (id int(11),value1 float(10,2));
INSERT INTO t1 VALUES (1,0.00),(1,1.00), (1,2.00), (2,10.00), (2,11.00), (2,12.00);
CREATE TABLE t2 (id int(11),name char(20));
INSERT INTO t2 VALUES (1,'Set One'),(2,'Set Two');
select id, avg(value1), std(value1), variance(value1) from t1 group by id;
id	avg(value1)	std(value1)	variance(value1)
1	1.0000000	0.816497	0.666667
2	11.0000000	0.816497	0.666667
select name, avg(value1), std(value1), variance(value1) from t1, t2 where t1.id = t2.id group by t1.id;
name	avg(value1)	std(value1)	variance(value1)
Set One	1.0000000	0.816497	0.666667
Set Two	11.0000000	0.816497	0.666667
drop table t1,t2;
create table t1 (id int not null);
create table t2 (id int not null,rating int null);
insert into t1 values(1),(2),(3);
insert into t2 values(1, 3),(2, NULL),(2, NULL),(3, 2),(3, NULL);
select t1.id, avg(rating) from t1 left join t2 on ( t1.id = t2.id ) group by t1.id;
id	avg(rating)
1	3.00000
2	NULL
3	2.00000
select sql_small_result t2.id, avg(rating) from t2 group by t2.id;
id	avg(rating)
1	3.00000
2	NULL
3	2.00000
select sql_big_result t2.id, avg(rating) from t2 group by t2.id;
id	avg(rating)
1	3.00000
2	NULL
3	2.00000
select sql_small_result t2.id, avg(rating+0.0e0) from t2 group by t2.id;
id	avg(rating+0.0e0)
1	3
2	NULL
3	2
select sql_big_result t2.id, avg(rating+0.0e0) from t2 group by t2.id;
id	avg(rating+0.0e0)
1	3
2	NULL
3	2
drop table t1,t2;
create table t1 (a smallint(6) primary key, c char(10), b text);
INSERT INTO t1 VALUES (1,'1','1');
INSERT INTO t1 VALUES (2,'2','2');
INSERT INTO t1 VALUES (4,'4','4');
select count(*) from t1;
count(*)
3
select count(*) from t1 where a = 1;
count(*)
1
select count(*) from t1 where a = 100;
count(*)
0
select count(*) from t1 where a >= 10;
count(*)
0
select count(a) from t1 where a = 1;
count(a)
1
select count(a) from t1 where a = 100;
count(a)
0
select count(a) from t1 where a >= 10;
count(a)
0
select count(b) from t1 where b >= 2;
count(b)
2
select count(b) from t1 where b >= 10;
count(b)
0
select count(c) from t1 where c = 10;
count(c)
0
drop table t1;
CREATE TABLE t1 (d DATETIME, i INT);
INSERT INTO t1 VALUES (NOW(), 1);
SELECT COUNT(i), i, COUNT(i)*i FROM t1 GROUP BY i;
COUNT(i)	i	COUNT(i)*i
1	1	1
SELECT COUNT(i), (i+0), COUNT(i)*(i+0) FROM t1 GROUP BY i;
COUNT(i)	(i+0)	COUNT(i)*(i+0)
1	1	1
DROP TABLE t1;
create table t1 (
num float(5,2),
user char(20)
);
insert into t1 values (10.3,'nem'),(20.53,'monty'),(30.23,'sinisa');
insert into t1 values (30.13,'nem'),(20.98,'monty'),(10.45,'sinisa');
insert into t1 values (5.2,'nem'),(8.64,'monty'),(11.12,'sinisa');
select sum(num) from t1;
sum(num)
147.58
select sum(num) from t1 group by user;
sum(num)
50.15
45.63
51.80
drop table t1;
create table t1 (a1 int, a2 char(3), key k1(a1), key k2(a2));
insert into t1 values(10,'aaa'), (10,null), (10,'bbb'), (20,'zzz');
create table t2(a1 char(3), a2 int, a3 real, key k1(a1), key k2(a2, a1));
select * from t1;
a1	a2
10	aaa
10	NULL
10	bbb
20	zzz
select min(a2) from t1;
min(a2)
aaa
select max(t1.a1), max(t2.a2) from t1, t2;
max(t1.a1)	max(t2.a2)
NULL	NULL
select max(t1.a1) from t1, t2;
max(t1.a1)
NULL
select max(t2.a2), max(t1.a1) from t1, t2;
max(t2.a2)	max(t1.a1)
NULL	NULL
explain select min(a2) 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
explain select max(t1.a1), max(t2.a2) 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	No matching min/max row
insert into t2 values('AAA', 10, 0.5);
insert into t2 values('BBB', 20, 1.0);
select t1.a1, t1.a2, t2.a1, t2.a2 from t1,t2;
a1	a2	a1	a2
10	aaa	AAA	10
10	aaa	BBB	20
10	NULL	AAA	10
10	NULL	BBB	20
10	bbb	AAA	10
10	bbb	BBB	20
20	zzz	AAA	10
20	zzz	BBB	20
select max(t1.a1), max(t2.a1) from t1, t2 where t2.a2=9;
max(t1.a1)	max(t2.a1)
NULL	NULL
select max(t2.a1), max(t1.a1) from t1, t2 where t2.a2=9;
max(t2.a1)	max(t1.a1)
NULL	NULL
select t1.a1, t1.a2, t2.a1, t2.a2 from t1 left outer join t2 on t1.a1=10;
a1	a2	a1	a2
10	aaa	AAA	10
10	aaa	BBB	20
10	NULL	AAA	10
10	NULL	BBB	20
10	bbb	AAA	10
10	bbb	BBB	20
20	zzz	NULL	NULL
select max(t1.a2) from t1 left outer join t2 on t1.a1=10;
max(t1.a2)
zzz
select max(t2.a1) from t2 left outer join t1 on t2.a2=10 where t2.a2=20;
max(t2.a1)
BBB
select max(t2.a1) from t2 left outer join t1 on t2.a2=10 where t2.a2=10;
max(t2.a1)
AAA
select max(t2.a1) from t1 left outer join t2 on t1.a2=t2.a1 and 1=0 where t2.a1='AAA';
max(t2.a1)
NULL
select max(t1.a2),max(t2.a1) from t1 left outer join t2 on t1.a1=10;
max(t1.a2)	max(t2.a1)
zzz	BBB
drop table t1,t2;
CREATE TABLE t1 (a int, b int);
select count(b), sum(b), avg(b), std(b), min(b), max(b), bit_and(b), bit_or(b) from t1;
count(b)	sum(b)	avg(b)	std(b)	min(b)	max(b)	bit_and(b)	bit_or(b)
0	NULL	NULL	NULL	NULL	NULL	18446744073709551615	0
select a,count(b), sum(b), avg(b), std(b), min(b), max(b), bit_and(b), bit_or(b) from t1 group by a;
a	count(b)	sum(b)	avg(b)	std(b)	min(b)	max(b)	bit_and(b)	bit_or(b)
insert into t1 values (1,null);
select a,count(b), sum(b), avg(b), std(b), min(b), max(b), bit_and(b), bit_or(b) from t1 group by a;
a	count(b)	sum(b)	avg(b)	std(b)	min(b)	max(b)	bit_and(b)	bit_or(b)
1	0	NULL	NULL	NULL	NULL	NULL	18446744073709551615	0
insert into t1 values (1,null);
insert into t1 values (2,null);
select a,count(b), sum(b), avg(b), std(b), min(b), max(b), bit_and(b), bit_or(b) from t1 group by a;
a	count(b)	sum(b)	avg(b)	std(b)	min(b)	max(b)	bit_and(b)	bit_or(b)
1	0	NULL	NULL	NULL	NULL	NULL	18446744073709551615	0
2	0	NULL	NULL	NULL	NULL	NULL	18446744073709551615	0
select SQL_BIG_RESULT a,count(b), sum(b), avg(b), std(b), min(b), max(b), bit_and(b), bit_or(b) from t1 group by a;
a	count(b)	sum(b)	avg(b)	std(b)	min(b)	max(b)	bit_and(b)	bit_or(b)
1	0	NULL	NULL	NULL	NULL	NULL	18446744073709551615	0
2	0	NULL	NULL	NULL	NULL	NULL	18446744073709551615	0
insert into t1 values (2,1);
select a,count(b), sum(b), avg(b), std(b), min(b), max(b), bit_and(b), bit_or(b) from t1 group by a;
a	count(b)	sum(b)	avg(b)	std(b)	min(b)	max(b)	bit_and(b)	bit_or(b)
1	0	NULL	NULL	NULL	NULL	NULL	18446744073709551615	0
2	1	1	1.00000	0.00000	1	1	1	1
select SQL_BIG_RESULT a,count(b), sum(b), avg(b), std(b), min(b), max(b), bit_and(b), bit_or(b) from t1 group by a;
a	count(b)	sum(b)	avg(b)	std(b)	min(b)	max(b)	bit_and(b)	bit_or(b)
1	0	NULL	NULL	NULL	NULL	NULL	18446744073709551615	0
2	1	1	1.00000	0.00000	1	1	1	1
insert into t1 values (3,1);
select a,count(b), sum(b), avg(b), std(b), min(b), max(b), bit_and(b), bit_or(b) from t1 group by a;
a	count(b)	sum(b)	avg(b)	std(b)	min(b)	max(b)	bit_and(b)	bit_or(b)
1	0	NULL	NULL	NULL	NULL	NULL	18446744073709551615	0
2	1	1	1.00000	0.00000	1	1	1	1
3	1	1	1.00000	0.00000	1	1	1	1
select SQL_BIG_RESULT a,count(b), sum(b), avg(b), std(b), min(b), max(b), bit_and(b), bit_or(b), bit_xor(b) from t1 group by a;
a	count(b)	sum(b)	avg(b)	std(b)	min(b)	max(b)	bit_and(b)	bit_or(b)	bit_xor(b)
1	0	NULL	NULL	NULL	NULL	NULL	18446744073709551615	0	0
2	1	1	1.00000	0.00000	1	1	1	1	1
3	1	1	1.00000	0.00000	1	1	1	1	1
explain extended select SQL_BIG_RESULT a,count(b), sum(b), avg(b), std(b), min(b), max(b), bit_and(b), bit_or(b), bit_xor(b) from t1 group by a;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	5	Using filesort
Warnings:
Note	1003	select sql_big_result `test`.`t1`.`a` AS `a`,count(`test`.`t1`.`b`) AS `count(b)`,sum(`test`.`t1`.`b`) AS `sum(b)`,avg(`test`.`t1`.`b`) AS `avg(b)`,std(`test`.`t1`.`b`) AS `std(b)`,min(`test`.`t1`.`b`) AS `min(b)`,max(`test`.`t1`.`b`) AS `max(b)`,bit_and(`test`.`t1`.`b`) AS `bit_and(b)`,bit_or(`test`.`t1`.`b`) AS `bit_or(b)`,bit_xor(`test`.`t1`.`b`) AS `bit_xor(b)` from `test`.`t1` group by `test`.`t1`.`a`
drop table t1;
create table t1 (col int);
insert into t1 values (-1), (-2), (-3);
select bit_and(col), bit_or(col) from t1;
bit_and(col)	bit_or(col)
18446744073709551612	18446744073709551615
select SQL_BIG_RESULT bit_and(col), bit_or(col) from t1 group by col;
bit_and(col)	bit_or(col)
18446744073709551613	18446744073709551613
18446744073709551614	18446744073709551614
18446744073709551615	18446744073709551615
drop table t1;
create table t1 (a int);
select avg(2) from t1;
avg(2)
NULL
drop table t1;
create table t1(
a1 char(3) primary key,
a2 smallint,
a3 char(3),
a4 real,
a5 date,
key k1(a2,a3),
key k2(a4 desc,a1),
key k3(a5,a1)
);
create table t2(
a1 char(3) primary key,
a2 char(17),
a3 char(2),
a4 char(3),
key k1(a3, a2),
key k2(a4)
);
insert into t1 values('AME',0,'SEA',0.100,date'1942-02-19');
insert into t1 values('HBR',1,'SEA',0.085,date'1948-03-05');
insert into t1 values('BOT',2,'SEA',0.085,date'1951-11-29');
insert into t1 values('BMC',3,'SEA',0.085,date'1958-09-08');
insert into t1 values('TWU',0,'LAX',0.080,date'1969-10-05');
insert into t1 values('BDL',0,'DEN',0.080,date'1960-11-27');
insert into t1 values('DTX',1,'NYC',0.080,date'1961-05-04');
insert into t1 values('PLS',1,'WDC',0.075,date'1949-01-02');
insert into t1 values('ZAJ',2,'CHI',0.075,date'1960-06-15');
insert into t1 values('VVV',2,'MIN',0.075,date'1959-06-28');
insert into t1 values('GTM',3,'DAL',0.070,date'1977-09-23');
insert into t1 values('SSJ',null,'CHI',null,date'1974-03-19');
insert into t1 values('KKK',3,'ATL',null,null);
insert into t1 values('XXX',null,'MIN',null,null);
insert into t1 values('WWW',1,'LED',null,null);
insert into t2 values('TKF','Seattle','WA','AME');
insert into t2 values('LCC','Los Angeles','CA','TWU');
insert into t2 values('DEN','Denver','CO','BDL');
insert into t2 values('SDC','San Diego','CA','TWU');
insert into t2 values('NOL','New Orleans','LA','GTM');
insert into t2 values('LAK','Los Angeles','CA','TWU');
insert into t2 values('AAA','AAA','AA','AME');
select * from t1;
a1	a2	a3	a4	a5
AME	0	SEA	0.1	1942-02-19
HBR	1	SEA	0.085	1948-03-05
BOT	2	SEA	0.085	1951-11-29
BMC	3	SEA	0.085	1958-09-08
TWU	0	LAX	0.08	1969-10-05
BDL	0	DEN	0.08	1960-11-27
DTX	1	NYC	0.08	1961-05-04
PLS	1	WDC	0.075	1949-01-02
ZAJ	2	CHI	0.075	1960-06-15
VVV	2	MIN	0.075	1959-06-28
GTM	3	DAL	0.07	1977-09-23
SSJ	NULL	CHI	NULL	1974-03-19
KKK	3	ATL	NULL	NULL
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 (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';
execute stmt1;
max(a)
2
execute stmt1;
max(a)
2
execute stmt1;
max(a)
2
deallocate prepare stmt1;
drop table t1;
CREATE TABLE t1 (a int primary key);
INSERT INTO t1 VALUES (1),(2),(3),(4);
SELECT MAX(a) FROM t1 WHERE a > 5;
MAX(a)
NULL
SELECT MIN(a) FROM t1 WHERE a < 0;
MIN(a)
NULL
DROP TABLE t1;
CREATE TABLE t1 (
id int(10) unsigned NOT NULL auto_increment,
val enum('one','two','three') NOT NULL default 'one',
PRIMARY KEY  (id)
) ENGINE=MyISAM DEFAULT CHARSET=utf8;
INSERT INTO t1 VALUES
(1,'one'),(2,'two'),(3,'three'),(4,'one'),(5,'two');
select val, count(*) from t1 group by val;
val	count(*)
one	2
two	2
three	1
drop table t1;
CREATE TABLE t1 (
id int(10) unsigned NOT NULL auto_increment,
val set('one','two','three') NOT NULL default 'one',
PRIMARY KEY  (id)
) ENGINE=MyISAM DEFAULT CHARSET=utf8;
INSERT INTO t1 VALUES
(1,'one'),(2,'two'),(3,'three'),(4,'one'),(5,'two');
select val, count(*) from t1 group by val;
val	count(*)
one	2
two	2
three	1
drop table t1;
create table t1(a int, b datetime);
insert into t1 values (1, NOW()), (2, NOW());
create table t2 select MAX(b) from t1 group by a;
show create table t2;
Table	Create Table
t2	CREATE TABLE `t2` (
  `MAX(b)` datetime DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=latin1
drop table t1, t2;
create table t1(f1 datetime);
insert into t1 values (now());
create table t2 select f2 from (select max(now()) f2 from t1) a;
show columns from t2;
Field	Type	Null	Key	Default	Extra
f2	datetime	YES		NULL	
drop table t2;
create table t2 select f2 from (select now() f2 from t1) a;
show columns from t2;
Field	Type	Null	Key	Default	Extra
f2	datetime	NO		0000-00-00 00:00:00	
drop table t2, t1;
CREATE TABLE t1(
id int PRIMARY KEY,
a  int,
b  int,
INDEX i_b_id(a,b,id),
INDEX i_id(a,id)
);
INSERT INTO t1 VALUES 
(1,1,4), (2,2,1), (3,1,3), (4,2,1), (5,1,1);
SELECT MAX(id) FROM t1 WHERE id < 3 AND a=2 AND b=6;
MAX(id)
NULL
DROP TABLE t1;
CREATE TABLE t1(
id int PRIMARY KEY,
a  int,
b  int,
INDEX i_id(a,id),
INDEX i_b_id(a,b,id)
);
INSERT INTO t1 VALUES 
(1,1,4), (2,2,1), (3,1,3), (4,2,1), (5,1,1);
SELECT MAX(id) FROM t1 WHERE id < 3 AND a=2 AND b=6;
MAX(id)
NULL
DROP TABLE t1;
create table t2 (ff double);
insert into t2 values (2.2);
select cast(sum(distinct ff) as decimal(5,2)) from t2;
cast(sum(distinct ff) as decimal(5,2))
2.20
select cast(sum(distinct ff) as signed) from t2;
cast(sum(distinct ff) as signed)
2
select cast(variance(ff) as decimal(10,3)) from t2;
cast(variance(ff) as decimal(10,3))
0.000
select cast(min(ff) as decimal(5,2)) from t2;
cast(min(ff) as decimal(5,2))
2.20
create table t1 (df decimal(5,1));
insert into t1 values(1.1);
insert into t1 values(2.2);
select cast(sum(distinct df) as signed) from t1;
cast(sum(distinct df) as signed)
3
select cast(min(df) as signed) from t1;
cast(min(df) as signed)
0
select 1e8 * sum(distinct df) from t1;
1e8 * sum(distinct df)
330000000
select 1e8 * min(df) from t1;
1e8 * min(df)
110000000
create table t3 (ifl int);
insert into t3 values(1), (2);
select cast(min(ifl) as decimal(5,2)) from t3;
cast(min(ifl) as decimal(5,2))
1.00
drop table t1, t2, t3;
CREATE TABLE t1 (id int(11),value1 float(10,2));
INSERT INTO t1 VALUES (1,0.00),(1,1.00), (1,2.00), (2,10.00), (2,11.00), (2,12.00), (2,13.00);
select id, stddev_pop(value1), var_pop(value1), stddev_samp(value1), var_samp(value1) from t1 group by id;
id	stddev_pop(value1)	var_pop(value1)	stddev_samp(value1)	var_samp(value1)
1	0.816497	0.666667	1.000000	1.000000
2	1.118034	1.250000	1.290994	1.666667
DROP TABLE t1;
CREATE TABLE t1 (col1 decimal(16,12));
INSERT INTO t1 VALUES (-5.00000000001),(-5.00000000002),(-5.00000000003),(-5.00000000000),(-5.00000000001),(-5.00000000002);
insert into t1 select * from t1;
select col1,count(col1),sum(col1),avg(col1) from t1 group by col1;
col1	count(col1)	sum(col1)	avg(col1)
-5.000000000030	2	-10.000000000060	-5.00000000003000000
-5.000000000020	4	-20.000000000080	-5.00000000002000000
-5.000000000010	4	-20.000000000040	-5.00000000001000000
-5.000000000000	2	-10.000000000000	-5.00000000000000000
DROP TABLE t1;
create table t1 (col1 decimal(16,12));
insert into t1 values (-5.00000000001);
insert into t1 values (-5.00000000001);
select col1,sum(col1),max(col1),min(col1) from t1 group by col1;
col1	sum(col1)	max(col1)	min(col1)
-5.000000000010	-10.000000000020	-5.000000000010	-5.000000000010
delete from t1;
insert into t1 values (5.00000000001);
insert into t1 values (5.00000000001);
select col1,sum(col1),max(col1),min(col1) from t1 group by col1;
col1	sum(col1)	max(col1)	min(col1)
5.000000000010	10.000000000020	5.000000000010	5.000000000010
DROP TABLE t1;
CREATE TABLE t1 (a VARCHAR(400));
INSERT INTO t1 (a) VALUES ("A"), ("a"), ("a "), ("a   "),
("B"), ("b"), ("b "), ("b   ");
SELECT COUNT(DISTINCT a) FROM t1;
COUNT(DISTINCT a)
2
DROP TABLE t1;
CREATE TABLE t1 (a int, b int, c int);
INSERT INTO t1 (a, b, c) VALUES
(1,1,1), (1,1,2), (1,1,3),
(1,2,1), (1,2,2), (1,2,3),
(1,3,1), (1,3,2), (1,3,3),
(2,1,1), (2,1,2), (2,1,3),
(2,2,1), (2,2,2), (2,2,3),
(2,3,1), (2,3,2), (2,3,3),
(3,1,1), (3,1,2), (3,1,3),
(3,2,1), (3,2,2), (3,2,3),
(3,3,1), (3,3,2), (3,3,3);
SELECT b/c as v, a FROM t1 ORDER BY v;
v	a
0.33333	3
0.33333	1
0.33333	2
0.50000	1
0.50000	2
0.50000	3
0.66667	2
0.66667	1
0.66667	3
1.00000	3
1.00000	2
1.00000	3
1.00000	1
1.00000	2
1.00000	3
1.00000	2
1.00000	1
1.00000	1
1.50000	3
1.50000	2
1.50000	1
2.00000	1
2.00000	3
2.00000	2
3.00000	3
3.00000	2
3.00000	1
SELECT b/c as v, SUM(a) FROM t1 GROUP BY v;
v	SUM(a)
0.33333	6
0.50000	6
0.66667	6
1.00000	18
1.50000	6
2.00000	6
3.00000	6
SELECT SUM(a) FROM t1 GROUP BY b/c;
SUM(a)
6
6
6
18
6
6
6
DROP TABLE t1;
set div_precision_increment= @sav_dpi;
