Id Email UserName
1 Taiseer.Joudeh@hotmail.com TaiseerJoudeh
2 Hasan.Ahmad@mymail.com HasanAhmad
3 Moatasem.Ahmad@outlook.com MoatasemAhmad
4 Salma.Tamer@outlook.com SalmaTamer
5 Ahmad.Radi@gmail.com AhmadRadi
6 Bill.Gates@yahoo.com BillGates
7 Shareef.Khaled@gmail.com ShareefKhaled
8 Aram.Naser@gmail.com AramNaser
9 Layla.Ibrahim@mymail.com LaylaIbrahim
10 Rema.Oday@hotmail.com RemaOday
11 Fikri.Husein@gmail.com FikriHusein
12 Zakari.Husein@outlook.com ZakariHusein
13 Taher.Waleed@mymail.com LaylaIbrahim
14 Tamer.Wesam@yahoo.com TamerWesam
15 Khaled.Hasaan@gmail.com KhaledHasaan
16 Asaad.Ibrahim@hotmail.com AsaadIbrahim
17 Tareq.Nassar@outlook.com TareqNassar
18 Diana.Lutfi@outlook.com DianaLutfi
19 Tamara.Malek@gmail.com TamaraMalek
20 Arwa.Kamal@yahoo.com ArwaKamal
21 Jana.Ahmad@yahoo.com SalmaTamer
22 Nisreen.Tamer@gmail.com NisreenTamer
23 Noura.Ahmad@outlook.com 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
)