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Oracle删除重复记录妙解
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下一篇 2017-08-17 20:15:53
/ 个人分类:数据库知识
少量数据:
三部曲:
1.create table a as select distinct * from b;
2.truncate table b;
3.insert into b select * from a;
大量数据:
way1: delete from test a where rowid not in(select max(b.rowid) from test b where a.id=b.id and a.name=b.name...)
way2: delete from test a where rowid <(select max(b.rowid) from test b where a.id=b.id.....)(换>,则 max换min)
way3: delete from test where rowid not in (select max(rowid) from test a group by a.id,a.name...)
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数据库Oracle