数据清理——删除多个字段重复的记录

最新推荐文章于 2024-10-31 21:32:30 发布

转载最新推荐文章于 2024-10-31 21:32:30 发布 · 547 阅读

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原文链接：http://www.cnblogs.com/sjqq/p/9757398.html

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#数据库

数据库内容，随机编了一些数据，其中认为两个字段Name、Address1一致为重复记录，保留其中一条

删除两个字段Name、Address1一致重　　复的记录，保留一条：
- 找出，（如果没有第三行，会有什么问题呢？可将示例数据中 ID 为4的行，Name字段改为Tom测试一下）

1 select * from tableabc
2 where Name in( select Name from tableabc group by Name, Address1 having count(Name) > 1)
3 and Address1 in( select Address1 from tableabc group by Name, Address1 having count(Address1) > 1)

- 删除

1 select * from tableabc 
2 where Name in( select Name from tableabc group by Name, Address1 having count(Name) > 1)
3 and Address1 in( select Address1 from tableabc group by Name, Address1 having count(Address1) > 1)
4 and ID not in(select max(ID) from tableabc group by Name,Address1 having count(Name) > 1 )

转载于:https://www.cnblogs.com/sjqq/p/9757398.html