当前位置:Gxlcms > mysql > Mysql删除重复的数据Mysql数据去重复

Mysql删除重复的数据Mysql数据去重复

时间:2021-07-01 10:21:17 帮助过:43人阅读

MySQL数据库中查询重复数据

select * from employee group by emp_name having count (*)>1;

Mysql  查询可以删除的重复数据

select t1.* from employee t1 where (t1.emp_name) in (select t4.emp_name from (select t2.emp_name from employee t2 group by t2.emp_name having count(*)>1) t4) and t1.emp_id not in (select t5.emp_id from (select min(t3.emp_id) as emp_id from employee t3 group by t3.emp_name having count(*)>1) t5);

Mysql  删除重复的数据

delete t1 from employee t1 where (t1.emp_name) in (select t4.emp_name from (select t2.emp_name from employee t2 group by t2.emp_name having count(*)>1) t4) and t1.emp_id not in (select t5.emp_id from (select min(t3.emp_id) as emp_id from employee t3 group by t3.emp_name having count(*)>1) t5);

您可能感兴趣的文章:

  • 一条sql语句完成MySQL去重留一
  • MySQL去重的方法整理
  • mysql 开发技巧之JOIN 更新和数据查重/去重
  • mysql去重的两种方法详解及实例代码
  • MySQL数据表合并去重的简单实现方法
  • mysql自联去重的一些笔记记录

人气教程排行