题解 | 获取当前薪水第二多的员工的emp_no以及其对应的薪水salary

select
    a.emp_no,
    b.salary,
    a.last_name,
    a.first_name
from
    employees a
    join salaries b using (emp_no)
where
    b.salary = (
        select
            max(salary)
        from
            salaries
        where
            salary < (
                select
                    max(salary)
                from
                    salaries
            )
    )