

delete from A where UserName in (select UserName from A group by UserName having count(UserName)>1) and UserID not in (select min(UserID) from A group by UserName having count(UserName)>1)
delete from A where UserName in (select UserName from A group by UserName having count(UserName)>1) and UserID not in (select min(UserID) from A group by UserName having count(UserName)>1)
转载于:https://www.cnblogs.com/zuimeideshi520/p/6025493.html