题解

此题关键思维点在于，将给的两张表转换为，入职工资情况表和当前工资情况表，这样一来涨幅就很容易查询了

SELECT a.emp1_no, (b.nowsalary - a.hiresalary) growth
FROM (SELECT e1.emp_no emp1_no, s1.salary hiresalary
     FROM employees e1, salaries s1
     WHERE e1.emp_no = s1.emp_no
     AND e1.hire_date = s1.from_date) a
     RIGHT JOIN 
     (SELECT e2.emp_no emp2_no, s2.salary nowsalary 
     FROM employees e2, salaries s2
     WHERE e2.emp_no = s2.emp_no
     AND s2.to_date = '9999-01-01') b
     ON a.emp1_no = b.emp2_no
ORDER BY growth