题解 | 获取员工其当前的薪水比其manager当前薪水高

select
    de.emp_no,
    dm.emp_no as manager_no,
    s1.salary as emp_salary,
    s2.salary as manager_salary
from
    dept_emp de
    inner join dept_manager dm on de.dept_no = dm.dept_no
    inner join salaries s1 on de.emp_no = s1.emp_no #该员工工资
    inner join salaries s2 on dm.emp_no = s2.emp_no #该员工的manager的工资
where
    s1.salary > s2.salary

salaries被join两次，一次查员工工资，一次查该员工经理的工资

速度不是特别快，但没有子查询，通俗好懂~