select r1.emp_no emp_no,
r2.emp_no manager_no,
r1.salary emp_salary,
r2.salary manager_salary
from
(select d1.emp_no ,
s.salary,
dept_no
from dept_emp d1 left join salaries s on d1.emp_no=s.emp_no) r1 join
(select d2.emp_no,
s.salary,
dept_no
from dept_manager d2 left join salaries s on d2.emp_no=s.emp_no) r2 on r1.dept_no=r2.dept_no
where r1.salary>r2.salary
# 通过 r1.dept_no=r2.dept_no 实现了区分不同部门的员工和领导，确保同一部门的员工薪水和同一部门的领导的薪水作比较