You can't specify target table ''"

mysql中不能查自己同时更新自己，需要把子查询的查询结果用个临时表装

报错sql语句：

delete from tb_task_detail where main_id in (select main_id from tb_task_detail where id = 5 )

修改后sql语句

delete from tb_task_detail where main_id in (select * from (select main_id from tb_task_detail where id = 5 )a)