drop table if exists t1,t2;
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	68.7500
Computer	6900	1380.0000
Phone	10	10.0000
TV	600	120.0000
NULL	7785	519.0000
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	Extra
1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	15	Using temporary; 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	50.00
Calculator:1	:2000:	2	75.00
Calculator:1	NULL	2	62.50
Calculator:2	:2000:	2	75.00
Calculator:2	NULL	2	75.00
Computer:1	:1999:	2	1350.00
Computer:1	:2000:	2	1500.00
Computer:1	NULL	2	1400.00
Computer:2	:2000:	2	1350.00
Computer:2	NULL	2	1350.00
Phone:3	:2003:	2	10.00
Phone:3	NULL	2	10.00
TV:1	:1999:	2	125.00
TV:1	:2000:	2	150.00
TV:1	NULL	2	133.33
TV:2	:2000:	2	100.00
TV:2	NULL	2	100.00
NULL	NULL	2	519.00
select product, sum(profit)/count(*) from t1 group by product with rollup;
product	sum(profit)/count(*)
Calculator	68.75
Computer	1380.00
Phone	10.00
TV	120.00
NULL	519.00
select left(product,4) as prod, sum(profit)/count(*) from t1 group by prod with rollup;
prod	sum(profit)/count(*)
Calc	68.75
Comp	1380.00
Phon	10.00
TV	120.00
NULL	519.00
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	62.50
Calculator:2	2	75.00
Computer:1	2	1400.00
Computer:2	2	1350.00
Phone:3	2	10.00
TV:1	2	133.33
TV:2	2	100.00
NULL	2	519.00
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	68.7500
:Computer:	6900	1380.0000
:Phone:	10	10.0000
:TV:	600	120.0000
:TV:	7785	519.0000
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;