题解 | #平均工资#

查询出salaries 中 除去了最大值和最小值后的表再进行计算

可以确保最大值和最小值不止一条的情况去除所有最大值最小值

select avg(salary) as avg_salary
from salaries
where to_date='9999-01-01'
and salary!=(select max(salary) from salaries
             where to_date='9999-01-01')
and salary!=(select min(salary) from salaries
            where to_date='9999-01-01')