题解 | #平均工资#

select
    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')