SQLSERVER 删除重复记录

1、查找表中多余的重复记录，重复记录是根据单个字段（peopleId）来判断
select 
* from people
where peopleId in (select peopleId from 
people group by peopleId having count(peopleId) 
> 1) 

2、删除表中多余的重复记录，重复记录是根据单个字段（peopleId）来判断，只留有rowid最小的记录
delete 
from people
where peopleId in (select peopleId from 
people group by peopleId having 
count(peopleId) > 1)
and rowid not in (select min(rowid) from 
people group by peopleId having count(peopleId 
)>1)

3、查找表中多余的重复记录（多个字段）
select * from vitae a
where (a.peopleId,a.seq) 
in (select peopleId,seq from vitae group by peopleId,seq having 
count(*) > 1)

4、删除表中多余的重复记录（多个字段），只留有rowid最小的记录
delete from vitae a
where 
(a.peopleId,a.seq) in (select peopleId,seq from vitae group by 
peopleId,seq having count(*) > 1)
and rowid not in (select min(rowid) from 
vitae group by peopleId,seq having count(*)>1)

5、查找表中多余的重复记录（多个字段），不包含rowid最小的记录
select * from vitae a
where 
(a.peopleId,a.seq) in (select peopleId,seq from vitae group by 
peopleId,seq having count(*) > 1)
and rowid not in (select min(rowid) from 
vitae group by peopleId,seq having count(*)>1)

(二)
比方说
在A表中存在一个字段“name”，
而且不同记录之间的“name”值有可能会相同，
现在就是需要查询出在该表中的各记录之间，“name”值存在重复的项；
Select 
Name,Count(*) From A Group By Name Having Count(*) > 1

如果还查性别也相同大则如下:
Select Name,sex,Count(*) From A Group By Name,sex Having 
Count(*) > 1

本文转自tiasys博客园博客，原文链接：http://www.cnblogs.com/tiasys/archive/2012/09/22/2697728.html，如需转载请自行联系原作者