SQL server 数据库 ——聚合函数（一列 多行，值类型）

聚合函数

聚合函数：

1、max最大值   select max(price) from car where code='c024'

2、min最小值   select * from car where oil= (select min(price) from car) 

3、avg平均值    select avg(price) as 平均价格  from car 

4、sum求和    select sum (price) from car 

5、count数量  select count (*) from car

起别名：

  select avg(price) as 平均价格  from car

1.select * from car oil in (7.4,8.5,8.6) 

2.select * from car oil not in (7.4,8.5,8.6)

3.select *from car where oil >=7 and oil <=8

4.select * from car where oil between 7 and 8

5.select *from car where oil >any(select oil from car where code='c024' or code ='c014')

6.select * from car where oil >all(select oil from car where code='c024' or code ='c014')