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 (product varchar(32), country_id int not null, year int, profit int);
insert into t1  values ( 'Computer', 2,2000, 1200),
( 'TV', 1, 1999, 150),
( 'Calculator', 1, 1999,50),
( 'Computer', 1, 1999,1500),
( 'Computer', 1, 2000,1500),
( 'TV', 1, 2000, 150),
( 'TV', 2, 2000, 100),
( 'TV', 2, 2000, 100),
( 'Calculator', 1, 2000,75),
( 'Calculator', 2, 2000,75),
( 'TV', 1, 1999, 100),
( 'Computer', 1, 1999,1200),
( 'Computer', 2, 2000,1500),
( 'Calculator', 2, 2000,75),
( 'Phone', 3, 2003,10)
;
create table t2 (country_id int primary key, country char(20) not null);
insert into t2 values (1, 'USA'),(2,'India'), (3,'Finland');
select product, sum(profit) from t1 group by product;
product	sum(profit)
Calculator	275
Computer	6900
Phone	10
TV	600
select product, sum(profit) from t1 group by product with rollup;
product	sum(profit)
Calculator	275
Computer	6900
Phone	10
TV	600
NULL	7785
select product, sum(profit) from t1 group by 1 with rollup;
product	sum(profit)
Calculator	275
Computer	6900
Phone	10
TV	600
NULL	7785
select product, sum(profit),avg(profit) from t1 group by product with rollup;
product	sum(profit)	avg(profit)
Calculator	275	68.75000
Computer	6900	1380.00000
Phone	10	10.00000
TV	600	120.00000
NULL	7785	519.00000
select product, country_id , year, sum(profit) from t1 group by product, country_id, year;
product	country_id	year	sum(profit)
Calculator	1	1999	50
Calculator	1	2000	75
Calculator	2	2000	150
Computer	1	1999	2700
Computer	1	2000	1500
Computer	2	2000	2700
Phone	3	2003	10
TV	1	1999	250
TV	1	2000	150
TV	2	2000	200
select product, country_id , year, sum(profit) from t1 group by product, country_id, year with rollup;
product	country_id	year	sum(profit)
Calculator	1	1999	50
Calculator	1	2000	75
Calculator	1	NULL	125
Calculator	2	2000	150
Calculator	2	NULL	150
Calculator	NULL	NULL	275
Computer	1	1999	2700
Computer	1	2000	1500
Computer	1	NULL	4200
Computer	2	2000	2700
Computer	2	NULL	2700
Computer	NULL	NULL	6900
Phone	3	2003	10
Phone	3	NULL	10
Phone	NULL	NULL	10
TV	1	1999	250
TV	1	2000	150
TV	1	NULL	400
TV	2	2000	200
TV	2	NULL	200
TV	NULL	NULL	600
NULL	NULL	NULL	7785
explain extended select product, country_id , year, sum(profit) from t1 group by product, country_id, year with rollup;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	15	100.00	Using filesort
Warnings:
Note	1003	select `test`.`t1`.`product` AS `product`,`test`.`t1`.`country_id` AS `country_id`,`test`.`t1`.`year` AS `year`,sum(`test`.`t1`.`profit`) AS `sum(profit)` from `test`.`t1` group by `test`.`t1`.`product`,`test`.`t1`.`country_id`,`test`.`t1`.`year` with rollup
select product, country_id , sum(profit) from t1 group by product desc, country_id with rollup;
product	country_id	sum(profit)
TV	1	400
TV	2	200
TV	NULL	600
Phone	3	10
Phone	NULL	10
Computer	1	4200
Computer	2	2700
Computer	NULL	6900
Calculator	1	125
Calculator	2	150
Calculator	NULL	275
NULL	NULL	7785
select product, country_id , year, sum(profit) from t1 group by product, country_id, year with rollup limit 5;
product	country_id	year	sum(profit)
Calculator	1	1999	50
Calculator	1	2000	75
Calculator	1	NULL	125
Calculator	2	2000	150
Calculator	2	NULL	150
select product, country_id , year, sum(profit) from t1 group by product, country_id, year with rollup limit 3,3;
product	country_id	year	sum(profit)
Calculator	2	2000	150
Calculator	2	NULL	150
Calculator	NULL	NULL	275
select product, country_id, count(*), count(distinct year) from t1 group by product, country_id;
product	country_id	count(*)	count(distinct year)
Calculator	1	2	2
Calculator	2	2	1
Computer	1	3	2
Computer	2	2	1
Phone	3	1	1
TV	1	3	2
TV	2	2	1
select product, country_id, count(*), count(distinct year) from t1 group by product, country_id with rollup;
product	country_id	count(*)	count(distinct year)
Calculator	1	2	2
Calculator	2	2	1
Calculator	NULL	4	2
Computer	1	3	2
Computer	2	2	1
Computer	NULL	5	2
Phone	3	1	1
Phone	NULL	1	1
TV	1	3	2
TV	2	2	1
TV	NULL	5	2
NULL	NULL	15	3
select product, country_id , year, sum(profit) from t1 group by product, country_id, year with rollup having country_id = 1;
product	country_id	year	sum(profit)
Calculator	1	1999	50
Calculator	1	2000	75
Calculator	1	NULL	125
Computer	1	1999	2700
Computer	1	2000	1500
Computer	1	NULL	4200
TV	1	1999	250
TV	1	2000	150
TV	1	NULL	400
select product, country_id , year, sum(profit) from t1 group by product, country_id, year with rollup having sum(profit) > 200;
product	country_id	year	sum(profit)
Calculator	NULL	NULL	275
Computer	1	1999	2700
Computer	1	2000	1500
Computer	1	NULL	4200
Computer	2	2000	2700
Computer	2	NULL	2700
Computer	NULL	NULL	6900
TV	1	1999	250
TV	1	NULL	400
TV	NULL	NULL	600
NULL	NULL	NULL	7785
select product, country_id , year, sum(profit) from t1 group by product, country_id, year with rollup having sum(profit) > 7000;
product	country_id	year	sum(profit)
NULL	NULL	NULL	7785
select concat(product,':',country_id) as 'prod', concat(":",year,":") as 'year',1+1, sum(profit)/count(*) from t1 group by 1,2 with rollup;
prod	year	1+1	sum(profit)/count(*)
Calculator:1	:1999:	2	50.00000
Calculator:1	:2000:	2	75.00000
Calculator:1	NULL	2	62.50000
Calculator:2	:2000:	2	75.00000
Calculator:2	NULL	2	75.00000
Computer:1	:1999:	2	1350.00000
Computer:1	:2000:	2	1500.00000
Computer:1	NULL	2	1400.00000
Computer:2	:2000:	2	1350.00000
Computer:2	NULL	2	1350.00000
Phone:3	:2003:	2	10.00000
Phone:3	NULL	2	10.00000
TV:1	:1999:	2	125.00000
TV:1	:2000:	2	150.00000
TV:1	NULL	2	133.33333
TV:2	:2000:	2	100.00000
TV:2	NULL	2	100.00000
NULL	NULL	2	519.00000
select product, sum(profit)/count(*) from t1 group by product with rollup;
product	sum(profit)/count(*)
Calculator	68.75000
Computer	1380.00000
Phone	10.00000
TV	120.00000
NULL	519.00000
select left(product,4) as prod, sum(profit)/count(*) from t1 group by prod with rollup;
prod	sum(profit)/count(*)
Calc	68.75000
Comp	1380.00000
Phon	10.00000
TV	120.00000
NULL	519.00000
select concat(product,':',country_id), 1+1, sum(profit)/count(*) from t1 group by concat(product,':',country_id) with rollup;
concat(product,':',country_id)	1+1	sum(profit)/count(*)
Calculator:1	2	62.50000
Calculator:2	2	75.00000
Computer:1	2	1400.00000
Computer:2	2	1350.00000
Phone:3	2	10.00000
TV:1	2	133.33333
TV:2	2	100.00000
NULL	2	519.00000
select product, country , year, sum(profit) from t1,t2 where t1.country_id=t2.country_id group by product, country, year with rollup;
product	country	year	sum(profit)
Calculator	India	2000	150
Calculator	India	NULL	150
Calculator	USA	1999	50
Calculator	USA	2000	75
Calculator	USA	NULL	125
Calculator	NULL	NULL	275
Computer	India	2000	2700
Computer	India	NULL	2700
Computer	USA	1999	2700
Computer	USA	2000	1500
Computer	USA	NULL	4200
Computer	NULL	NULL	6900
Phone	Finland	2003	10
Phone	Finland	NULL	10
Phone	NULL	NULL	10
TV	India	2000	200
TV	India	NULL	200
TV	USA	1999	250
TV	USA	2000	150
TV	USA	NULL	400
TV	NULL	NULL	600
NULL	NULL	NULL	7785
select product, `sum` from (select product, sum(profit) as 'sum' from t1 group by product with rollup) as tmp where product is null;
product	sum
NULL	7785
select product from t1 where exists (select product, country_id , sum(profit) from t1 as t2 where t1.product=t2.product group by product, country_id with rollup having sum(profit) > 6000);
product
Computer
Computer
Computer
Computer
Computer
select product, country_id , year, sum(profit) from t1 group by product, country_id, year having country_id is NULL;
product	country_id	year	sum(profit)
select concat(':',product,':'), sum(profit),avg(profit) from t1 group by product with rollup;
concat(':',product,':')	sum(profit)	avg(profit)
:Calculator:	275	68.75000
:Computer:	6900	1380.00000
:Phone:	10	10.00000
:TV:	600	120.00000
NULL	7785	519.00000
select product, country_id , year, sum(profit) from t1 group by product, country_id, year with cube;
ERROR 42000: This version of MySQL doesn't yet support 'CUBE'
explain select product, country_id , year, sum(profit) from t1 group by product, country_id, year with cube;
ERROR 42000: This version of MySQL doesn't yet support 'CUBE'
select product, country_id , year, sum(profit) from t1 group by product, country_id, year with cube union all select product, country_id , year, sum(profit) from t1 group by product, country_id, year with rollup;
ERROR 42000: This version of MySQL doesn't yet support 'CUBE'
drop table t1,t2;
CREATE TABLE t1 (i int);
INSERT INTO t1 VALUES(100);
CREATE TABLE t2 (i int);
INSERT INTO t2 VALUES (100),(200);
SELECT i, COUNT(*) FROM t1 GROUP BY i WITH ROLLUP;
i	COUNT(*)
100	1
NULL	1
SELECT t1.i, t2.i, COUNT(*) FROM t1,t2 GROUP BY t1.i,t2.i WITH ROLLUP;
i	i	COUNT(*)
100	100	1
100	200	1
100	NULL	2
NULL	NULL	2
drop table t1,t2;
CREATE TABLE user_day(
user_id INT NOT NULL,
date DATE NOT NULL,
UNIQUE INDEX user_date (user_id, date)
);
INSERT INTO user_day VALUES
(1, '2004-06-06' ),
(1, '2004-06-07' ),
(2, '2004-06-06' );
SELECT
d.date AS day,
COUNT(d.user_id) as sample,
COUNT(next_day.user_id) AS not_cancelled
FROM user_day d
LEFT JOIN user_day next_day 
ON next_day.user_id=d.user_id AND 
next_day.date= DATE_ADD( d.date, interval 1 day )
GROUP BY day;
day	sample	not_cancelled
2004-06-06	2	1
2004-06-07	1	0
SELECT
d.date AS day,
COUNT(d.user_id) as sample,
COUNT(next_day.user_id) AS not_cancelled
FROM user_day d
LEFT JOIN user_day next_day 
ON next_day.user_id=d.user_id AND 
next_day.date= DATE_ADD( d.date, interval 1 day )
GROUP BY day
WITH ROLLUP;
day	sample	not_cancelled
2004-06-06	2	1
2004-06-07	1	0
NULL	3	1
DROP TABLE user_day;
CREATE TABLE t1 (a int, b int);
INSERT INTO t1 VALUES
(1,4),
(2,2), (2,2),
(4,1), (4,1), (4,1), (4,1),
(2,1), (2,1);
SELECT SUM(b) FROM t1 GROUP BY a WITH ROLLUP;
SUM(b)
4
6
4
14
SELECT DISTINCT SUM(b) FROM t1 GROUP BY a WITH ROLLUP;
SUM(b)
4
6
14
SELECT SUM(b), COUNT(DISTINCT b) FROM t1 GROUP BY a WITH ROLLUP;
SUM(b)	COUNT(DISTINCT b)
4	1
6	2
4	1
14	3
SELECT DISTINCT SUM(b), COUNT(DISTINCT b) FROM t1 GROUP BY a WITH ROLLUP;
SUM(b)	COUNT(DISTINCT b)
4	1
6	2
14	3
SELECT SUM(b), COUNT(*) FROM t1 GROUP BY a WITH ROLLUP;
SUM(b)	COUNT(*)
4	1
6	4
4	4
14	9
SELECT DISTINCT SUM(b), COUNT(*) FROM t1 GROUP BY a WITH ROLLUP;
SUM(b)	COUNT(*)
4	1
6	4
4	4
14	9
SELECT SUM(b), COUNT(DISTINCT b), COUNT(*) FROM t1 GROUP BY a WITH ROLLUP;
SUM(b)	COUNT(DISTINCT b)	COUNT(*)
4	1	1
6	2	4
4	1	4
14	3	9
SELECT DISTINCT SUM(b), COUNT(DISTINCT b), COUNT(*) FROM t1
GROUP BY a WITH ROLLUP;
SUM(b)	COUNT(DISTINCT b)	COUNT(*)
4	1	1
6	2	4
4	1	4
14	3	9
SELECT a, sum(b) FROM t1 GROUP BY a,b WITH ROLLUP;
a	sum(b)
1	4
1	4
2	2
2	4
2	6
4	4
4	4
NULL	14
SELECT DISTINCT a, sum(b) FROM t1 GROUP BY a,b WITH ROLLUP;
a	sum(b)
1	4
2	2
2	4
2	6
4	4
NULL	14
SELECT b, a, sum(b) FROM t1 GROUP BY a,b WITH ROLLUP;
b	a	sum(b)
4	1	4
NULL	1	4
1	2	2
2	2	4
NULL	2	6
1	4	4
NULL	4	4
NULL	NULL	14
SELECT DISTINCT b,a, sum(b) FROM t1 GROUP BY a,b WITH ROLLUP;
b	a	sum(b)
4	1	4
NULL	1	4
1	2	2
2	2	4
NULL	2	6
1	4	4
NULL	4	4
NULL	NULL	14
ALTER TABLE t1 ADD COLUMN c INT;
SELECT a,b,sum(c) FROM t1 GROUP BY a,b,c WITH ROLLUP;
a	b	sum(c)
1	4	NULL
1	4	NULL
1	NULL	NULL
2	1	NULL
2	1	NULL
2	2	NULL
2	2	NULL
2	NULL	NULL
4	1	NULL
4	1	NULL
4	NULL	NULL
NULL	NULL	NULL
SELECT distinct a,b,sum(c) FROM t1 GROUP BY a,b,c WITH ROLLUP;
a	b	sum(c)
1	4	NULL
1	NULL	NULL
2	1	NULL
2	2	NULL
2	NULL	NULL
4	1	NULL
4	NULL	NULL
NULL	NULL	NULL
DROP TABLE t1;
CREATE TABLE t1 (a int, b int);
INSERT INTO t1 VALUES
(1,4),
(2,2), (2,2),
(4,1), (4,1), (4,1), (4,1),
(2,1), (2,1);
SELECT a, SUM(b) FROM t1 GROUP BY a WITH ROLLUP LIMIT 1;
a	SUM(b)
1	4
SELECT SQL_CALC_FOUND_ROWS a, SUM(b) FROM t1 GROUP BY a WITH ROLLUP LIMIT 1;
a	SUM(b)
1	4
DROP TABLE t1;
CREATE TABLE t1 (a int(11) NOT NULL);
INSERT INTO t1 VALUES (1),(2);
SELECT a, SUM(a) m FROM  t1 GROUP BY a WITH ROLLUP;
a	m
1	1
2	2
NULL	3
SELECT * FROM ( SELECT a, SUM(a) m FROM  t1 GROUP BY a WITH ROLLUP ) t2;
a	m
1	1
2	2
NULL	3
DROP TABLE t1;
set div_precision_increment= @sav_dpi;
CREATE TABLE t1 (a int(11));
INSERT INTO t1 VALUES (1),(2);
SELECT a, SUM(a), SUM(a)+1 FROM (SELECT a FROM t1 UNION select 2) d 
GROUP BY a;
a	SUM(a)	SUM(a)+1
1	1	2
2	2	3
SELECT a, SUM(a), SUM(a)+1 FROM (SELECT a FROM t1 UNION select 2) d 
GROUP BY a WITH ROLLUP;
a	SUM(a)	SUM(a)+1
1	1	2
2	2	3
NULL	3	4
SELECT a, SUM(a), SUM(a)+1 FROM (SELECT 1 a UNION select 2) d 
GROUP BY a;
a	SUM(a)	SUM(a)+1
1	1	2
2	2	3
SELECT a, SUM(a), SUM(a)+1 FROM (SELECT 1 a UNION select 2) d 
GROUP BY a WITH ROLLUP;
a	SUM(a)	SUM(a)+1
1	1	2
2	2	3
NULL	3	4
SELECT a, SUM(a), SUM(a)+1, CONCAT(SUM(a),'x'), SUM(a)+SUM(a), SUM(a)
FROM (SELECT 1 a, 2 b UNION SELECT 2,3 UNION SELECT 5,6 ) d
GROUP BY a WITH ROLLUP;
a	SUM(a)	SUM(a)+1	CONCAT(SUM(a),'x')	SUM(a)+SUM(a)	SUM(a)
1	1	2	1x	2	1
2	2	3	2x	4	2
5	5	6	5x	10	5
NULL	8	9	8x	16	8
DROP TABLE t1;
CREATE TABLE t1 (a int(11));
INSERT INTO t1 VALUES (1),(2);
SELECT a, a+1, SUM(a) FROM t1 GROUP BY a WITH ROLLUP;
a	a+1	SUM(a)
1	2	1
2	3	2
NULL	NULL	3
SELECT a+1 FROM t1 GROUP BY a WITH ROLLUP;
a+1
2
3
NULL
SELECT a+SUM(a) FROM t1 GROUP BY a WITH ROLLUP;
a+SUM(a)
2
4
NULL
SELECT a, a+1 as b FROM t1 GROUP BY a WITH ROLLUP HAVING b > 2;
a	b
2	3
SELECT a, a+1 as b FROM t1 GROUP BY a WITH ROLLUP HAVING a IS NULL;
a	b
NULL	NULL
SELECT a, a+1 as b FROM t1 GROUP BY a WITH ROLLUP HAVING b IS NULL;
a	b
NULL	NULL
SELECT IFNULL(a, 'TEST') FROM t1 GROUP BY a WITH ROLLUP;
IFNULL(a, 'TEST')
1
2
TEST
CREATE TABLE t2 (a int, b int);
INSERT INTO t2 VALUES
(1,4),
(2,2), (2,2),
(4,1), (4,1), (4,1), (4,1),
(2,1), (2,1);
SELECT a,b,SUM(b) FROM t2 GROUP BY a,b WITH ROLLUP;
a	b	SUM(b)
1	4	4
1	NULL	4
2	1	2
2	2	4
2	NULL	6
4	1	4
4	NULL	4
NULL	NULL	14
SELECT a,b,SUM(b), a+b as c FROM t2
GROUP BY a,b WITH ROLLUP HAVING c IS NULL;
a	b	SUM(b)	c
1	NULL	4	NULL
2	NULL	6	NULL
4	NULL	4	NULL
NULL	NULL	14	NULL
SELECT IFNULL(a, 'TEST'), COALESCE(b, 'TEST') FROM t2 
GROUP BY a, b WITH ROLLUP;
IFNULL(a, 'TEST')	COALESCE(b, 'TEST')
1	4
1	TEST
2	1
2	2
2	TEST
4	1
4	TEST
TEST	TEST
DROP TABLE t1,t2;
CREATE TABLE t1 (a INT(10) NOT NULL, b INT(10) NOT NULL);
INSERT INTO t1 VALUES (1, 1);
INSERT INTO t1 VALUES (1, 2);
SELECT a, b, a AS c, COUNT(*) AS count FROM t1 GROUP BY a, b, c WITH ROLLUP;
a	b	c	count
1	1	1	1
1	1	NULL	1
1	2	1	1
1	2	NULL	1
1	NULL	NULL	2
NULL	NULL	NULL	2
DROP TABLE t1;
CREATE TABLE t1 (a int(11) NOT NULL);
INSERT INTO t1 VALUES (1),(2);
SELECT * FROM (SELECT a, a + 1, COUNT(*) FROM t1 GROUP BY a WITH ROLLUP) t;
a	a + 1	COUNT(*)
1	2	1
2	3	1
NULL	NULL	2
SELECT * FROM (SELECT a, LENGTH(a), COUNT(*) FROM t1 GROUP BY a WITH ROLLUP) t;
a	LENGTH(a)	COUNT(*)
1	1	1
2	1	1
NULL	NULL	2
DROP TABLE t1;
create table t1 ( a varchar(9), b int );
insert into t1 values('a',1),(null,2);
select a, max(b) from t1 group by a with rollup;
a	max(b)
NULL	2
a	1
NULL	2
select distinct a, max(b) from t1 group by a with rollup;
a	max(b)
NULL	2
a	1
drop table t1;
create table t1 (a varchar(22) not null , b int);
insert into t1 values ("2006-07-01 21:30", 1), ("2006-07-01 23:30", 10);
select left(a,10), a, sum(b) from t1 group by 1,2 with rollup;
left(a,10)	a	sum(b)
2006-07-01	2006-07-01 21:30	1
2006-07-01	2006-07-01 23:30	10
2006-07-01	NULL	11
NULL	NULL	11
select left(a,10) x, a, sum(b) from t1 group by x,a with rollup;
x	a	sum(b)
2006-07-01	2006-07-01 21:30	1
2006-07-01	2006-07-01 23:30	10
2006-07-01	NULL	11
NULL	NULL	11
drop table t1;
CREATE TABLE t1 (a int, b int);
INSERT INTO t1 
VALUES (2,10),(3,30),(2,40),(1,10),(2,30),(1,20),(2,10);
SELECT a, SUM(b) FROM t1 GROUP BY a WITH ROLLUP;
a	SUM(b)
1	30
2	90
3	30
NULL	150
SELECT DISTINCT a, SUM(b) FROM t1 GROUP BY a WITH ROLLUP;
a	SUM(b)
1	30
2	90
3	30
NULL	150
SELECT a, b, COUNT(*) FROM t1 GROUP BY a,b WITH ROLLUP;
a	b	COUNT(*)
1	10	1
1	20	1
1	NULL	2
2	10	2
2	30	1
2	40	1
2	NULL	4
3	30	1
3	NULL	1
NULL	NULL	7
SELECT DISTINCT a, b, COUNT(*) FROM t1 GROUP BY a,b WITH ROLLUP;
a	b	COUNT(*)
1	10	1
1	20	1
1	NULL	2
2	10	2
2	30	1
2	40	1
2	NULL	4
3	30	1
3	NULL	1
NULL	NULL	7
SELECT 'x', a, SUM(b) FROM t1 GROUP BY 1,2 WITH ROLLUP;
x	a	SUM(b)
x	1	30
x	2	90
x	3	30
x	NULL	150
NULL	NULL	150
SELECT DISTINCT 'x', a, SUM(b) FROM t1 GROUP BY 1,2 WITH ROLLUP;
x	a	SUM(b)
x	1	30
x	2	90
x	3	30
x	NULL	150
NULL	NULL	150
SELECT DISTINCT 'x', a, SUM(b) FROM t1 GROUP BY 1,2 WITH ROLLUP;
x	a	SUM(b)
x	1	30
x	2	90
x	3	30
x	NULL	150
NULL	NULL	150
DROP TABLE t1;
CREATE TABLE t1(id int, type char(1));
INSERT INTO t1 VALUES
(1,"A"),(2,"C"),(3,"A"),(4,"A"),(5,"B"),
(6,"B"),(7,"A"),(8,"C"),(9,"A"),(10,"C");
CREATE VIEW v1 AS SELECT * FROM t1;
SELECT type FROM t1 GROUP BY type WITH ROLLUP;
type
A
B
C
NULL
SELECT type FROM v1 GROUP BY type WITH ROLLUP;
type
A
B
C
NULL
EXPLAIN SELECT type FROM v1 GROUP BY type WITH ROLLUP;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	10	Using filesort
DROP VIEW v1;
DROP TABLE t1;
CREATE TABLE t1 (a int(11) NOT NULL);
INSERT INTO t1 VALUES (1),(2);
CREATE VIEW v1 AS
SELECT a, LENGTH(a), COUNT(*) FROM t1 GROUP BY a WITH ROLLUP;
DESC v1;
Field	Type	Null	Key	Default	Extra
a	bigint(11)	YES		NULL	
LENGTH(a)	bigint(10)	YES		NULL	
COUNT(*)	bigint(21)	NO		0	
SELECT * FROM v1;
a	LENGTH(a)	COUNT(*)
1	1	1
2	1	1
NULL	NULL	2
DROP VIEW v1;
DROP TABLE t1;
CREATE TABLE t1 (a int, KEY (a));
INSERT INTO t1 VALUES (3), (1), (4), (1), (3), (1), (1);
SELECT * FROM (SELECT a, SUM(a) FROM t1 GROUP BY a WITH ROLLUP) as t;
a	SUM(a)
1	4
3	6
4	4
NULL	14
DROP TABLE t1;