题解 | #查找在职员工自入职以来的薪水涨幅情况#

select a.emp_no,(c.salary-b.salary) as growth
from      employees a
left join salaries  b
on        a.emp_no=b.emp_no
and      a.hire_date =b.from_date  #入职薪资
left join salaries c
on       a.emp_no=c.emp_no
and      c.to_date='9999-01-01'    #在职有效期薪资
where   c.emp_no is not null
order by growth;