数据库SQL实战 --53.查找排除当前最大、最小salary之后的员工的平均工资avg_salary

题目描述

查找排除当前最大、最小salary之后的员工的平均工资avg_salary。
CREATE TABLE `salaries` ( `emp_no` int(11) NOT NULL,
`salary` int(11) NOT NULL,
`from_date` date NOT NULL,
`to_date` date NOT NULL,
PRIMARY KEY (`emp_no`,`from_date`));

输出格式:

avg_salary

解决思路

SELECT AVG(salary) avg_salary FROM salaries
WHERE to_date = '9999-01-01'
AND salary NOT IN (SELECT MAX(salary) FROM salaries)
AND salary NOT IN (SELECT MIN(salary) FROM salaries)