Question

数据库问题，急求！

select
case When StuSelect = 'A' then '3'
When StuSelect = 'B' then '2'
When StuSelect = 'C' then '1'
else '0' end Score1
from Score

如果StuSelect 为A得3分，如果是B...
这样查下来之后，我要将这些分数统计起来总共多少分怎么做？
因为我的StuSelect是nvarchar型的，我用cast转换了下，但是做的时候老是报错。说'Score1' 附近有语法错误。

select
sum(cast(case When StuSelect = 'A' then '3'
When StuSelect = 'B' then '2'
When StuSelect = 'C' then '1'
else '0' end Score1)as jj)from Score

Answer 1

select
sum(cast ((case When StuSelect = 'A' then '3'
When StuSelect = 'B' then '2'
When StuSelect = 'C' then '1'
else '0' end ) as int))as scoresum from Score

别名 那其实默认是有as 的 所以语法错误 这样就可以了

Answer 2

select sum(scoreSum)
from (select
case When StuSelect = 'A' then '3'
When StuSelect = 'B' then '2'
When StuSelect = 'C' then '1'
else '0' end Score1 as scoreSum
from Score)

追问

因为我的StuSelect是nvarchar型的，所以老是报错。怎么办？关键字 'as' 附近有语法错误。

Answer 3

select
sum(cast(case When StuSelect = 'A' then '3'
When StuSelect = 'B' then '2'
When StuSelect = 'C' then '1'
else '0' end as int)) as Score1
from Score