Oracle 查詢重複數據

1、查找表中多餘的重複記錄（單個字段）

select  *  from table 
where  字段  in  (select  字段  from  table group by 字段 having count(字段) > 1)

2、查找表中多餘的重複記錄（多個字段） 

select * from table a
where (a.字段1,a.字段2) in (select 字段1，字段2 from table group by 字段1，字段2 having count(*) > 1)