select emp_no, salary, last_name, first_name from
employees join salaries using (emp_no)
where salary = 

(select max(salary) from employees inner join salaries using (emp_no)
where salary not in
(select max(salary) from salaries))

先找到第二高的salary，然后用emp_no作为结点连接俩张表，where salary 等于第二高。