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

# exists硬凑
SELECT
    t1.emp_no,
    t1.salary,
    last_name,
    first_name
FROM(
    SELECT
        emp_no,
        salary
    FROM
        salaries s1
    WHERE EXISTS(
        SELECT 1 FROM salaries s2 
        WHERE 
            s2.salary > s1.salary AND
            NOT EXISTS(
                SELECT 1 FROM salaries s3 WHERE s3.salary > s2.salary
            ) AND NOT EXISTS(
                SELECT 1 FROM salaries s4 WHERE s4.salary > s1.salary AND s4.salary != s2.salary
            )
    )
) t1
INNER JOIN
    employees e1
    ON e1.emp_no = t1.emp_no