怎样在Sql server的删除重复的记录,只留下一条?

[csdn_lee]

如题,即清除多余的记录.和SELECT DISTINCT 效果相同,不过是数据库本身中不含重复的

[yujohny]

蚂蚁的：去除重复值

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


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。

2,
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...)

[yujohny]

参考该贴
http://expert.csdn.net/Expert/topic/2225/2225703.xml?temp=.8897364

[lynx1111]

http://www.itpub.net/showthread.php?s=&threadid=162263

[sdhdy]

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