数据库SQL实战（牛客网）：查找所有员工自入职以来的薪水涨幅情况

查找所有员工自入职以来的薪水涨幅情况，给出员工编号emp_no以及其对应的薪水涨幅growth，并按照growth进行升序
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));

三表相连，b和c的salary分别代表当前薪资和入职薪资

select a.emp_no , (b.salary - c.salary) as growth
from employees as a 
join salaries as b
on a.emp_no = b.emp_no and b.to_date = '9999-01-01'
join salaries as c 
on a.emp_no = c.emp_no and a.hire_date = c.from_date
order by growth asc;