mysql

如何查出同一张表中字段值重复的记录

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)

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)