题解 | #获取员工其当前的薪水比其manager当前薪水还高的相关信息#

先找出经理的部门，员工号，工资， 然后找出员工的部门，员工号，工资，最后用部门连接2表， 取得答案

with a as 
(select m.dept_no, m.emp_no as manager_no, s.salary as manager_salary
from salaries s 
join dept_manager m
on s.emp_no = m.emp_no
where s.to_date='9999-01-01'),
b as 
(select e.dept_no, e.emp_no, s.salary as emp_salary
from dept_emp e 
join salaries s 
on e.emp_no = s.emp_no
where e.to_date='9999-01-01')

select b.emp_no, a.manager_no, b.emp_salary, a.manager_salary
from a 
join b 
on a.dept_no = b.dept_no
where emp_salary > manager_salary;