oracle删除重复数据保留第一条记录

oracle删除重复数据保留第一条记录

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）select * 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)PHP中文网，有大量免费的SQL教程，欢迎大家学习！以上就是oracle删除重复数据保留第一条记录的详细内容，更多请关注小潘博客其它相关文章！