1、查找表中多余的重复记录，重复记录是根据单个字段（aID）来判断
select * from A
where aID in (select aID from A group by aID having count(aID) > 1)
例二：
select * from testB
where numeber in (select number from A group by number having count(number) > 1 )
可以查出testB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（aID）来判断，只留有rowid最小的记录
delete from A
where aID in (select aID from A group by aID having count(aID) > 1)
and rowid not in (select min(rowid) from A group by aID having count(aID )>1)
3、查找表中多余的重复记录（多个字段）
select * from TableC a
where (a.aID,a.seq) in (select aID,seq from TableC group by aID,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 TableC a
where (a.aID,a.seq) in (select aID,seq from TableC group by aID,seq having count(*) > 1)
)
)
)
