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

# 连接表:经理工资表+员工工资表
# 用自己薪资减去老板薪资，如果大于0就选择
# 员工工资表
select 
    a.emp_no as emp_no,
    b.manager_no as manager_no,
    a.emp_salary as emp_salary,
    b.manager_salary as manager_salary
from
    (select
        de.dept_no as dept_no,
        de.emp_no as emp_no,
        s.salary as emp_salary
    from
        dept_emp as de
    inner join
        salaries as s
    on
        de.emp_no = s.emp_no) as a
left outer join
# 经理的工资表，有部门，经理，经理工资
    (select 
        dm.dept_no as dept_no,
        dm.emp_no as manager_no,
        s.salary as manager_salary
    from
        dept_manager as dm
    inner join 
        salaries as s
    on
        dm.emp_no = s.emp_no) as b
on 
    a.dept_no = b.dept_no
where
    emp_salary - manager_salary > 0