当前位置： 移动技术网 > IT编程>数据库>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

2017年12月12日  | 移动技术网IT编程  | 我要评论

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:

如对本文有疑问， 点击进行留言回复！！

相关文章:

验证码：
最近更新的文章
大家感兴趣的文章
移动技术网