zoukankan      html  css  js  c++  java
  • 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)
  • 相关阅读:
    遇到的一道发散思维题C#
    SQLSERVER函数判断当天是星期几
    C# Web 获取客户端IP
    C# 月度进度条实现
    FileZilla Server的安装和设置
    SQL1428N 应用程序已与 "DB2" 连接,
    DB2客户端连接服务器
    IIS提示Execute Access Denied解决办法
    dom4j java.lang.NoClassDefFoundError: org/jaxen/JaxenException
    Oracle查看用户、用户权限、用户表空间、用户默认表空间
  • 原文地址:https://www.cnblogs.com/luojianqun/p/4635184.html
Copyright © 2011-2022 走看看