題目要求查詢員工編號emp_no為10001其自入職以來的薪水salary漲幅值growth。

首先通過子查詢select salary from salaries where emp_no = 10001 order by to_date desc limit 0,1將當前的薪水找出來。

其次通過子查詢select salary from salaries where emp_no = 10001 order by to_date limit 0,1將剛入職時薪水找出來。

最後兩個相減，得到漲幅growth。

select (
(select salary from salaries where emp_no = 10001 order by to_date desc limit 0,1)
- (select salary from salaries where emp_no = 10001 order by to_date limit 0,1)
) as growth;