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-a.salary) as growth
from (select e.emp_no,s.salary
    from employees e left join salaries  s on e.emp_no=s.emp_no
    WHERE e.hire_date=s.from_date)a -- 入职工资表
 inner join 
    (select e.emp_no,s.salary
    from employees e left join salaries  s on e.emp_no=s.emp_no
    where s.to_date='9999-01-01')b -- 现在工资表
on a.emp_no=b.emp_no
order by growth

题目要求：入职以来的薪水涨幅情况，那就可以用现在的薪资 - 入职的薪资

现在的薪资

select e.emp_no,s.salary
    from employees e left join salaries  s on e.emp_no=s.emp_no
    where s.to_date='9999-01-01'

入职时的薪资

select e.emp_no,s.salary
    from employees e left join salaries  s on e.emp_no=s.emp_no
    WHERE e.hire_date=s.from_date

连接两表，按涨幅情况排序。完整代码如下

select b.emp_no,(b.salary-a.salary) as growth
from (select e.emp_no,s.salary
    from employees e left join salaries  s on e.emp_no=s.emp_no
    WHERE e.hire_date=s.from_date)a -- 入职工资表
 inner join 
    (select e.emp_no,s.salary
    from employees e left join salaries  s on e.emp_no=s.emp_no
    where s.to_date='9999-01-01')b -- 现在工资表
on a.emp_no=b.emp_no
order by growth