SQL Server重复记录查询、删除处理

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)