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 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。
5、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...)
6、select distinct * into #temp from tablename
delete tablename
go
insert tablename select * from #temp Sqlclub
go
drop table #temp
