sql 表中删除字段重复的行

Id    Email    UserName
1    [e-mail]    TaiseerJoudeh
2    [e-mail]    HasanAhmad
3    [e-mail]    MoatasemAhmad
4    [e-mail]    SalmaTamer
5    [e-mail]    AhmadRadi
6    [e-mail]    BillGates
7    [e-mail]    ShareefKhaled
8    [e-mail]    AramNaser
9    [e-mail]    LaylaIbrahim
10    [e-mail]    RemaOday
11    [e-mail]    FikriHusein
12    [e-mail]    ZakariHusein
13    [e-mail]    LaylaIbrahim
14    [e-mail]    TamerWesam
15    [e-mail]    KhaledHasaan
16    [e-mail]    AsaadIbrahim
17    [e-mail]    TareqNassar
18    [e-mail]    DianaLutfi
19    [e-mail]    TamaraMalek
20    [e-mail]    ArwaKamal
21    [e-mail]    SalmaTamer
22    [e-mail]    NisreenTamer
23    [e-mail]    SalmaTamer

去掉重复的UserName

delete Student2 where Id in

(
　　　　select id from (
　　　　　　select Id, UserName,ROW_NUMBER() over (partition by UserName order by id) orderid from Student2
　　　　)t1
　　　　where t1.orderid>1
)

delete from Students2 where id not in (

　　select min(id) from Students2 group by UserName

)