上一题目215题，最终形式

select owcs.emp_no,owcs.growth from
(select muqian.emp_no,(muqian.salary - douyou.salary) as growth
from 
    (select s.emp_no,s.salary
    from salaries s 
    where s.to_date = '9999-01-01') as muqian
inner join 
    (select s.emp_no,s.salary
    from employees e inner join salaries s on
    e.hire_date = s.from_date) as douyou
on muqian.emp_no = douyou.emp_no) as owcs
order by owcs.growth

215最终形式应该像这样