题解 | #查找排除当前最大、最小salary之后的员工的平均工资avg_salary#
查找排除当前最大、最小salary之后的员工的平均工资avg_salary
http://www.nowcoder.com/practice/95078e5e1fba4438b85d9f11240bc591
利用窗口函数
SELECT AVG(salary)
FROM (
SELECT *,
RANK() OVER(ORDER BY salary) r1,
RANK() OVER(ORDER BY salary DESC) r2
FROM salaries
WHERE to_date = '9999-01-01'
) a
WHERE r1!=1 AND r2!=1 