SQL重复记录查询的几种方法

http://www.jb51.net/article/34820.htm

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

复制代码 代码如下:

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

复制代码 代码如下:

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)