题解 | #SQL类别高难度试卷得分的截断平均值#

select
    b.tag,
    b.difficulty,
    round(avg(a.score),1) as clip_avg_score
from
    exam_record a 
left join 
    examination_info b on a.exam_id = b.exam_id
where 
    b.difficulty = 'hard' and b.tag = 'SQL' 
    and a.score < (select max(score) from exam_record) 
    and a.score > (select min(score) from exam_record)
group by 
    1,2