Home Database Mysql Tutorial 转载-MYSQL查询重复记录的步骤

转载-MYSQL查询重复记录的步骤

Jun 07, 2016 pm 04:26 PM
Inquire step Record repeat

转载---MYSQL查询重复记录的方法 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 select * from p

转载---MYSQL查询重复记录的方法
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
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
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)
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
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
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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