一直没有搞出来的SQL查询，望高手指点迷津

Question

表[T_Grade]中有记录如下：
Id           StuId          Score          Email
-------------------------------------------------------
1            9              12    [email protected]
2            9              10             [email protected]
3            8              13             [email protected]
4            7              12             [email protected]
5            6              11             [email protected]
-------------------------------------------------------
按Email 分组(group by email ), 获取最小的分数min(Score)
我怎么才能获取到这个最小分数的StuId

Answer 1

1.分组:
SELECT eMail,Min(Score) AS MinScore FROM [T_Grade] GROUP BY eMail2.获得最小分数的StuID
SELECT TOP 1 StuID FROM [T_Grade] ORDER BY Score

Answer 2

select 
   top 1  stuid 
from 
   table1 
where 
  score in(select min(score) from table1 group by email)

Answer 3

select top 1  stuid from table1 where score in(select min(score) from table1 group by email)

Answer 4

那么这样写:
SELECT T.*
FROM [T_Grade] T
JOIN (
SELECT eMail,Min(Score) AS MinScore FROM [T_Grade] GROUP BY eMail) T2 ON T.eMail=T2.eMail AND T.Score=T2.MinScore