理解关联子查询和非关联子查询
select staff_name from staff_member where
staff_id in (select staff_id from staff_func);
select staff_name from staff_member where
staff_id in (select staff_id from
staff_func where staff_member.staff_id = staff_func.staff_id);
请教哪句的执行效率 更高 ?为何?