码迷,mamicode.com
首页 > 数据库 > 详细

Oracle 删除重复数据只留一条

时间:2017-01-23 16:42:48      阅读:172      评论:0      收藏:0      [点我收藏+]

标签:min   font   from   log   logs   style   重复数   删除   color   

查询及删除重复记录的SQL语句
 
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 * fromwhere Id in (select Id fromgroup 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)

Oracle 删除重复数据只留一条

标签:min   font   from   log   logs   style   重复数   删除   color   

原文地址:http://www.cnblogs.com/alsf/p/6344283.html

(0)
(0)
   
举报
评论 一句话评论(0
登录后才能评论!
© 2014 mamicode.com 版权所有  联系我们:gaon5@hotmail.com
迷上了代码!