1.如果有ID字段，就是具有唯一性的字段

复制代码 代码如下:

delect table where id not in (
select max(id) from table group by col1,col2,col3...
)

复制代码 代码如下:

select * into #aa from table group by id1,id2,....
delete table
insert into table
select * from #aa

复制代码 代码如下:

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

复制代码 代码如下:

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
)

复制代码 代码如下:

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...)

复制代码 代码如下:

select distinct * into #temp from tablename
delete tablename
go
insert tablename select * from #temp Sqlclub
go
drop table #temp