dedecms织梦网站模板MYSQL查询重复记录的方法

dedecms织梦网站模板MYSQL查询重复记录的方法
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)