Question

SQLSERVER+怎么删除重复数据

Answer 1

问：SQLSERVER+怎么删除重复数据

答：你好，SQL Server删除重复行是我们最常见的操作之一，下面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。1.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。 2. 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 3. 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 4. 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,col3,col4 ) group