#不使用order by取出第二大的值：利用max（）
select s.emp_no,max(s.salary),e.last_name,e.first_name
from salaries s LEFT JOIN employees e on s.emp_no==e.emp_no
where salary!=(select max(all_salary) from 
(select  emp_no,sum(salary) as all_salary
from salaries
group by emp_no) as a)