题解 简单易懂 一个where搞定
获取员工其当前的薪水比其manager当前薪水还高的相关信息
http://www.nowcoder.com/practice/f858d74a030e48da8e0f69e21be63bef
select d1.emp_no,d2.emp_no,s.salary,s2.salary from dept_emp d1 join dept_manager d2 (on d1.dept_no=d2.dept_no) join salaries s on (d1.emp_no=s.emp_no) left join salaries s2 on (d2.emp_no=s2.emp_no) where (s.salary>s2.salary) and (d1.emp_no<>d2.emp_no)