各位用户为了找寻关于SQL去除重复记录（七种）的资料费劲了很多周折。这里教程网为您整理了关于SQL去除重复记录（七种）的相关资料，仅供查阅，以下为您介绍关于SQL去除重复记录（七种）的详细内容

话不多说，请看代码：

? 1 2 3 4 5 6 7 8 9 10 11 if not object_id('Tempdb..#T') is null  drop table #T Go Create table #T([ID] int,[Name] nvarchar(1),[Memo] nvarchar(2)) Insert #T select 1,N'A',N'A1' union all select 2,N'A',N'A2' union all select 3,N'A',N'A3' union all select 4,N'B',N'B1' union all select 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:

? 1 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:

? 1 2 delete a from #T a where ID>any(select ID from #T where Name=a.Name) select * from #T

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原文链接：http://www.cnblogs.com/zhangwc/p/6404306.html