题解 | 查找在职员工自入职以来的薪水涨幅情况
select b.emp_no, (b.salary-b.mi_salary) growth
from
(select s.emp_no, s.salary, a.mi_salary
from
(select s.emp_no, s.salary mi_salary
from employees e join salaries s on e.emp_no=s.emp_no
where from_date=hire_date
) a /*a表为所有员工入职工资*/ join salaries s on a.emp_no=s.emp_no
where to_date='9999-01-01'
) b
order by growth asc
