查找所有员工自入职以来的薪水涨幅情况

CREATE TABLE `employees` (
`emp_no` int(11) NOT NULL,
`birth_date` date NOT NULL,
`first_name` varchar(14) NOT NULL,
`last_name` varchar(16) NOT NULL,
`gender` char(1) NOT NULL,
`hire_date` date NOT NULL,
PRIMARY KEY (`emp_no`));
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`));

select end.emp_no,(end.salary - start.salary) growth from (select emp_no,salary from salaries where to_date = '9999-01-01') end left join (select s.emp_no,salary from salaries s inner join employees e on s.emp_no = e.emp_no where s.from_date = e.hire_date) start on start.emp_no = end.emp_no order by growth

-- 目前的工资
(select emp_no,salary from salaries where to_date = '9999-01-01') end

-- 最开始的工资
(select s.emp_no,salary from salaries s left join employees e on s.emp_no = e.emp_no where s.from_date = e.hire_date) start