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.salary-t1.salary as growth
from
(select e.emp_no,salary
from employees as e
left JOIN salaries as s
on e.emp_no=s.emp_no
where e.hire_date=s.from_date) as t1
join 
(select emp_no,salary
from salaries 
where to_date='9999-01-01') as t2
on t1.emp_no=t2.emp_no
order by growth 

创建一个入职表t1，和一个现任职表t2，用现任职的工资-入职工资