首页 > 教程 >

织梦网站MYSQL查询重复记录的方法

2023-02-27教程围观

简介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*frompeoplewherepeopleIdin(selectpeopleIdfrompeoplegroupbypeopleIdhavingcount(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deletefrompeop

  

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)   

下载链接:网站源码/小程序源码/网站模板下载

Tags: 网站 织梦 方法 查询 记录