题解 | 查找在职员工自入职以来的薪水涨幅情况

select
    t1.emp_no,
    (t2.sal_now - t1.sal_start) as growth
from
    (
        #获取入职工资
        select
            s.emp_no,
            s.salary as sal_start
        from
            salaries s
            join employees e on e.hire_date = s.from_date
    ) AS t1
    join (
        #获取现在工资
        select
            s.emp_no,
            s.salary as sal_now
        from
            salaries s
            join employees e on e.emp_no = s.emp_no
        where
            s.to_date = '9999-01-01'
    ) AS t2 on t1.emp_no = t2.emp_no
ORDER BY
    growth