SQL220 查找在职员工自入职以来的薪水涨幅情况
这题需要一个简单的注意力
入职工资->hire_date时的工资
在职员工当前工资->9999-01-01时的工资 （where可筛选）
然后两者相减即可
with in_salary as (select e.emp_no, s.salary
from employees e inner join salaries s
on e.emp_no = s.emp_no and s.from_date = e.hire_date),
cur_salary as(
select e.emp_no, s.salary
from employees e
inner join salaries s
on e.emp_no = s.emp_no
where s.to_date = '9999-01-01')
select i.emp_no, (cur.salary - i.salary) as growth
from in_salary i inner join cur_salary cur
on i.emp_no = cur.emp_no order by growth
