话不多说，请看代码：
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if not object_id('Tempdb..#T') is null drop table #TGoCreate table #T([ID] int,[Name] nvarchar(1),[Memo] nvarchar(2))Insert #Tselect 1,N'A',N'A1' union allselect 2,N'A',N'A2' union allselect 3,N'A',N'A3' union allselect 4,N'B',N'B1' union allselect 5,N'B',N'B2'Go |
--I、Name相同ID最小的记录(推荐用1,2,3),保留最小一条
方法1:
delete a from #T a where exists(select 1 from #T where Name=a.Name and ID<a.ID)
方法2:
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delete a from #T a left join (select min(ID)ID,Name from #T group by Name) b on a.Name=b.Name and a.ID=b.ID where b.Id is null |
方法3:
delete a from #T a where ID not in (select min(ID) from #T where Name=a.Name)
方法4(注:ID为唯一时可用):
delete a from #T a where ID not in(select min(ID)from #T group by Name)
方法5:
delete a from #T a where (select count(1) from #T where Name=a.Name and ID<a.ID)>0
方法6:
delete a from #T a where ID<>(select top 1 ID from #T where Name=a.name order by ID)
方法7:
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delete a from #T a where ID>any(select ID from #T where Name=a.Name)select * from #T |
以上就是本文的全部内容，希望本文的内容对大家的学习或者工作能带来一定的帮助，同时也希望多多支持服务器之家！
原文链接：http://www.cnblogs.com/zhangwc/p/6404306.html
