Mysql删除重复的数据的方法
发表时间:2023-08-24 来源:明辉站整理相关软件相关文章人气:
[摘要]这篇文章主要介绍了Mysql删除重复的数据 Mysql数据去重复,需要的朋友可以参考下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....
这篇文章主要介绍了
Mysql删除重复的数据 Mysql数据去重复,需要的朋友可以参考下
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);
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