GROUPING 运算符

一、说明

数据库：SQL SERVER

使用场合：对group by 聚合之后的数据再进行合计

二、数据准备

CREATE TABLE 
test.cnblogs.win_func (fname VARCHAR(200),fcity VARCHAR(200),fage INT,fsalary INT)
;



INSERT INTO test.cnblogs.win_func(FName,FCity,FAge,FSalary)
VALUES('Tom','BeiJing',20,3000);
INSERT INTO test.cnblogs.win_func(FName,FCity,FAge,FSalary)
VALUES('Tim','ChengDu',21,4000);
INSERT INTO test.cnblogs.win_func(FName,FCity,FAge,FSalary)
VALUES('Jim','BeiJing',22,3500);
INSERT INTO test.cnblogs.win_func(FName,FCity,FAge,FSalary)
VALUES('Lily','London',21,2000);
INSERT INTO test.cnblogs.win_func(FName,FCity,FAge,FSalary)
VALUES('John','NewYork',22,1000);
INSERT INTO test.cnblogs.win_func(FName,FCity,FAge,FSalary)
VALUES('YaoMing','BeiJing',20,3000);
INSERT INTO test.cnblogs.win_func(FName,FCity,FAge,FSalary)
VALUES('Swing','London',22,2000);
INSERT INTO test.cnblogs.win_func(FName,FCity,FAge,FSalary)
VALUES('Guo','NewYork',20,2800);
INSERT INTO test.cnblogs.win_func(FName,FCity,FAge,FSalary)
VALUES('YuQian','BeiJing',24,8000);
INSERT INTO test.cnblogs.win_func(FName,FCity,FAge,FSalary)
VALUES('Ketty','London',25,8500);
INSERT INTO test.cnblogs.win_func(FName,FCity,FAge,FSalary)
VALUES('Kitty','ChengDu',25,3000);
INSERT INTO test.cnblogs.win_func(FName,FCity,FAge,FSalary)
VALUES('Merry','BeiJing',23,3500);
INSERT INTO test.cnblogs.win_func(FName,FCity,FAge,FSalary)
VALUES('Smith','ChengDu',30,3000);
INSERT INTO test.cnblogs.win_func(FName,FCity,FAge,FSalary)
VALUES('Bill','BeiJing',25,2000);
INSERT INTO test.cnblogs.win_func(FName,FCity,FAge,FSalary)
VALUES('Jerry','NewYork',24,3300);

三、关键字

3.1 GROUPING

该函数再其参数列的值为超级分组记录所产生的的NULL时返回1，其他返回0。

SELECT  grouping(fcity) as fcity,grouping(fage) as fage,sum(fsalary) as '薪水' FROM test.cnblogs.win_func 
group by fcity,fage

本例为极端情况，没有超级分组，也不会有超级分组记录所产生的NULL；

一般与case when 配合使用，后面将和其他关键字配合说明

3.2 ROLLUP

同时得到小计与合计，类似Excel透视表

SELECT  fcity,fage,sum(fsalary) as '薪水' FROM test.cnblogs.win_func 
group by  ROLLUP(fcity,fage)

与GROUPING配合使用

SELECT  grouping(fcity) as fcity,grouping(fage) as fage,sum(fsalary) as '薪水' FROM test.cnblogs.win_func 
group by  ROLLUP(fcity,fage)

原超级分组记录所产生的的NULL时返回1，其他返回0。

与GROUPING、CASE WHEN 配合使用

select case when GROUPING(fcity)=1 then '总计' else fcity end as fcity, fage,sum(fsalary) as "薪水" FROM test.cnblogs.win_func 
group by  ROLLUP(fcity,fage)

3.3 CUBE

相较于ROLLUP,有更多的小计

SELECT  fcity,fage,sum(fsalary) as '薪水' FROM test.cnblogs.win_func 
group by  cube(fage,fcity)  --注意字段书写顺序

3.3 GROUPING SETS

只统计CUB中的小计，不含总计

SELECT  fage,fcity,sum(fsalary) as '薪水' FROM test.cnblogs.win_func 
group by  grouping sets(fage,fcity)