题解 | #SQL类别高难度试卷得分的截断平均值#

排除“一个”最大最小值，想到row_number窗口函数+子查询；
成功代码如下：（完全感觉做复杂了。。稍等看下大家怎么写的）

with x as(
select tag,difficulty,score,row_number() over(order by score desc ) r
from(
select score,tag,difficulty
from exam_record a
left join examination_info b
on a.exam_id = b.exam_id
where tag = "SQL" 
and difficulty = "hard"
and score is not null
)c
)
select tag,difficulty,round(avg(score),1) as clip_avg_score
from x
where r != (select max(r) from x) 
and r != (select min(r) from x)
group by tag,difficulty