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)
例二：
select * from testtable
where numeber in (select number from people group by number having count(number) > 1 )
可以查出testtable表中number相同的记录

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） 站长教学网 eduyo.com

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)

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