五种适合不同情况的SQL Server删除重复行的方法
对于SQL数据库!删除SQL Server重复行是我们最常见的操作之一,下面我们就为您介绍六种适合不同情况的SQL Server删除重复行的方法,供您参考。
一. 如果是判断所有字段也可以这样
select * into #aa from table group by id1,id2,.... delete table insert into table select * from #aa
二.如果有ID字段,就是具有唯一性的字段
delect table where id not in ( select max(id) from table group by col1,col2,col3... ) group by 子句后跟的字段就是你用来判断重复的条件,如只有col1,那么只要col1字段内容相同即表示记录相同http://www.woaidiannao.com。
三. 没有ID的情况
select identity(int,1,1) as id,* into #temp from tabel delect # where id not in ( select max(id) from # group by col1,col2,col3...) delect table inset into table(...) select ..... from #temp
col1+','+col2+','...col5 联合主键
select * from table where col1+','+col2+','...col5 in ( select max(col1+','+col2+','...col5) from table where having count(*)>1 group by col1,col2,col
三,col4 ) group by 子句后跟的字段就是你用来判断重复的条件,如只有col1,那么只要col1字段内容相同即表示记录相同。
四.
select distinct * into #temp from tablename delete tablename go insert tablename select * from #temp Sqlclub go drop table #temp
五.
select identity(int,1,1) as id,* into #temp from tabel select * from #temp where id in ( select max(id) from #emp where having count(*)>1 group by col1,col2,col3...)



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