题解 | 平均工资

with extremes as (
    select
        max(salary) as max_salary,
        min(salary) as min_salary
    from salaries
    where to_date = '9999-01-01'
)
select 
    avg(salary) as avg_salary
from salaries
where to_date = '9999-01-01' 
and (salary not in (select max_salary from extremes))
and (salary not in (select min_salary from extremes))

我发现我极容易用with语句，把一个比较简单的问题写成很长的代码。