获取薪水第二多的员工的empno以及其对应的薪水salary

select emp_no,
       salary,
       last_name,
       first_name
from employees
left join salaries using(emp_no)
where salary=(select max(salary) from salaries
              where salary<(select max(salary) from salaries))
/*排除掉第一最大值，选第二最大值。*/