题解 | #获取员工薪水比manager薪水还高的信息#

思路：一张表选出普通员工，另一张表选出经理，两表连接然后对比筛选即可。
select tb1.emp_no, tb2.emp_no, tb1.salary, tb2.salary
from (
(select emp_no, salary, dept_no
from salaries join dept_emp using(emp_no)
where emp_no not in (select emp_no from dept_manager)) as tb1

left join 

(select emp_no, salary, dept_no
from salaries join dept_emp using(emp_no)
where emp_no in (select emp_no from dept_manager)) as tb2
on tb1.dept_no=tb2.dept_no
) 
where tb1.salary>tb2.salary