gdjlc

培养良好的习惯,每天一点一滴的进步,终将会有收获。

  博客园 :: 首页 :: 博问 :: 闪存 :: 新随笔 :: 联系 :: 订阅 订阅 :: 管理 ::

sql删除重复数据


如果该表需要删除重复的记录(重复记录保留1条),可以按以下方法删除

select distinct * into #Tmp from tableName
drop table tableName
select * into tableName from #Tmp
drop table #Tmp

另一种方法是一个字段重复,ID不重复

delete 表 where id not in(
SELECT MAX(id) AS id FROM 表 GROUP BY rows) --- 删除重复行

select * from 表 where id in(
SELECT MAX(id) AS id FROM 表 GROUP BY rows) --重复行只查询一条

 

Oracle删除重复数据
delete from tb
where rowid not in (select min(rowid) from tb group by 重复字段 having count(重复字段)>1)

posted on 2008-10-07 12:44  gdjlc  阅读(232)  评论(0编辑  收藏  举报