题目描述
查找员工编号emp_no为10001其自入职以来的薪水salary涨幅(总共涨了多少)growth(可能有多次涨薪，没有降薪) CREATE TABLE `salaries` ( `emp_no` int(11) NOT NULL, `salary` int(11) NOT NULL, `from_date` date NOT NULL, `to_date` date NOT NULL, PRIMARY KEY (`emp_no`,`from_date`));
输入描述:
无
输出描述:
growth28841
--法一：最大减最小
SELECT MAX(S.salary)-MIN(S.salary) AS growth
FROM salaries S
WHERE S.emp_no=10001;
--法二：多次累加
select sum(s2.salary-s1.salary)
from salaries s1 , salaries s2
where s1.emp_no = 10001
and s1.to_date = s2.from_date
