mysql delete 执行报错：You can‘t specify target table ‘doctor_info‘ for update in FROM clause

因为一些测试原因，导致医生表里出现了两个医生ID相同的数据，也就是所谓的脏数据，那么如何把多余的那条删除掉呢？

一、首先筛选出条数大于1条的：

select doctor_id,count(doctor_id) from `doctor_info` where `scale_group_id`="31" group by doctor_id having count(doctor_id)>1

二、决定删除其中的那一条？max/min

1、max

select max(id) as id from doctor_group_permission where `scale_group_id`="24120868141551631" group by doctor_id  having count(doctor_id)>1

2、min

select min(id) as id from doctor_group_permission where `scale_group_id`="24120868141551631" group by doctor_id  having count(doctor_id)>1

三、数据筛选出来了，直接delete 报错了

 delete from doctor_info where id in(select max(id) as id from doctor_info where `scale_group_id`="31" group by doctor_id  having count(doctor_id)>1)

四、错误说明

不能先select出同一表中的某些值，再update这个表(在同一语句中)，即不能依据某字段值做判断再来更新某字段的值。
借用临时表来处理一下，前端时间写过一个update的，链接在此

五、正确delete操作 借用临时表a

delete from doctor_info where id in(select a.id from(select max(id) as id from doctor_info where `scale_group_id`="31" group by doctor_id  having count(doctor_id)>1) a)