case when then else end 怎样别名

--SQL中有判断的地方就可以用到他,相当于Excel的iif()函数,其他语言的if else
--如果怎样就怎样,否则就怎样
--比如,如果性别为1就显示为男,否则就显示为女
Select Name,case when Sex =0 then '男' else '女' end 性别
From ZlEmployee

--行转列
Select
Code,
Case when Sex=0 then Name else '' end As 男,
Case when Sex=1 then Name else '' end As 女
From ZlEmployee

--自定义排序
Select Name,Sex from ZlEmployee
order by case Left(Name,1)
when '赵' then 1
when '钱' then 2
when '孙' then 3
when '李' then 4
when '周' then 5
when '吴' then 6
when '郑' then 7
when '王' then 8
Else 9 End

select id, case when id = '10' then '1' end as bieming
from user
注意：end后面，加 as #{别名}