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 e.emp_no emp_no, s.salary salary, e.last_name last_name, e.first_name first_name
FROM salaries as s, employees as e
where s.emp_no = e.emp_no
and s.salary = (
            SELECT max(s2.salary)
            from salaries s2
            WHERE
                s2.salary < (
                            select max(salary) from salaries WHERE to_date = '9999-01-01'
                )
            AND s2.to_date = '9999-01-01'
);

思路: 连接两个表， 选择salary 最大的， 然后排除， 然后再选择最大的。