话不多说,请看代码:

  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:

  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:

  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沃谷博客!

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