如何用一条SQL语句删除两个关联表的记录？

有两个表：group_file和teach_classroom，其中的group_file.group_id和teach_classroom.classroom_id对应唯一

一条语句删除两个表的内容：

select a.*,b.classroom_name

from group_file a,teach_classroom b
where a.group_id=b.classroom_id;
delete a,b
from group_file as a
left join teach_classroom as b
on a.group_id=b.classroom_id

where b.classroom_id="classroom_20180508200911";

MySQL+Navicat上测试过。