MYSQL查询重复记录的方法

select * from hengtu_demandpush a
where (a.did,a.mid) in (select did,mid from hengtu_demandpush group by did,mid having count(*) > 1)

select * from hengtu_demandpush group by did,mid having count(*)>1

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

  1. select * from people   
  2. 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

  1. delete from people   
  2. where peopleId in (select peopleId from people group by peopleId   having count(peopleId) > 1)   
  3. 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)

  1. select * from vitae a   
  2. 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

  1. delete from vitae a   
  2. where (a.peopleId,a.seq) in (select peopleId,seq from vitae group by peopleId,seq having count(*) > 1)   
  3. 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

  1. select * from vitae a   
  2. where (a.peopleId,a.seq) in (select peopleId,seq from vitae group by peopleId,seq having count(*) > 1)   
  3. and rowid not in (select min(rowid) from vitae group by peopleId,seq having count(*)>1)
原文地址:https://www.cnblogs.com/luojianqun/p/4635184.html