日期:2014-05-16 浏览次数:20706 次
MYSQL查询重复记录的方法很多,下面就为您介绍几种最常用的MYSQL查询重复记录的方法,希望对您学习MYSQL查询重复记录方面能有所帮助。
1、查找表中多余的重复记录,重复记录是根据单个字段(peopleId)来判断
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select * from people where peopleId in (select peopleId from people group by peopleId having count(peopleId) > 1)?
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2、删除表中多余的重复记录,重复记录是根据单个字段(peopleId)来判断,只留有rowid最小的记录
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delete from people where peopleId in (select peopleId from people group by peopleId having count(peopleId) > 1) and rowid not in (select min(rowid) from people group by peopleId having count(peopleId )>1)?
3、查找表中多余的重复记录(多个字段)
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select * from vitae a where (a.peopleId,a.seq) in (select peopleId,seq from vitae group by peopleId,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
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delete from vitae a where (a.peopleId,a.seq) in (select peopleId,seq from vitae group by peopleId,seq having count(*) > 1) and rowid not in (select min(rowid) from vitae group by peopleId,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
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select * from vitae a where (a.peopleId,a.seq) in (select peopleId,seq from vitae group by peopleId,seq having count(*) > 1) and rowid not in (select min(rowid) from vitae group by peopleId,seq having count(*)>1)
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转载:http://database.51cto.com/art/201011/235159.htm
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