题解 | 获取每个部门中薪水最高的员工相关信息

select
    dept_no,
    dp.emp_no,
    salary
from
    dept_emp dp
    join salaries sl on dp.emp_no = sl.emp_no
where
    salary = (
        select
            sl
        from
            (
                select
                    dept_no,
                    max(salary) sl
                from
                    (
                        select
                            dept_no,
                            dp.emp_no,
                            salary
                        from
                            dept_emp dp
                            join salaries sl on dp.emp_no = sl.emp_no
                    ) s
                group by
                    dept_no
            ) m
        where
            m.dept_no = dp.dept_no
    )
order by
    dept_no;

套娃套出来了哈哈哈