关于Oracle中重复数据的处理

1）、查找表中多余的重复记录，重复记录是根据单个字段（Id）来判断

select * from 表 where Id in (select Id from 表 group byId having count(Id) > 1)

2）、删除表中多余的重复记录，重复记录是根据单个字段（Id）来判断，只留有rowid最小的记录

DELETE from 表 WHERE
(id) IN ( SELECT id FROM 表 GROUP BY id HAVING COUNT(id) > 1) AND
ROWID NOT IN (SELECT MIN(ROWID) FROM 表 GROUP BY
id HAVING COUNT(*) > 1);

              3）、查找表中多余的重复记录（多个字段）

slect * from 表 a where
(a.Id,a.seq) in(select Id,seq from 表 group by
Id,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 表 a where
(a.Id,a.seq) in (select Id,seq from 表 group by
Id,seq having count(*) > 1) and rowid not in (select min(rowid) from 表 group by Id,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 表 a where (a.Id,a.seq) in (select Id,seq from 表 group by Id,seq having count(*) > 1) and rowid not in (select
min(rowid) from 表 group by Id,seq having count(*)>1)