题解 | #SQL类别高难度试卷得分的截断平均值#

select d.tag,d.difficulty,FORMAT(sum(c.score)/count(c.uid),1) clip_avg_score
from exam_record c,examination_info d
where c.exam_id=d.exam_id
and d.tag='SQL'
and d.difficulty='hard'
and c.score <>(
    select min(score) mins from exam_record a,examination_info b
    where a.exam_id=b.exam_id
    and b.tag='SQL'
    and b.difficulty='hard'
)
and c.score <>(
    select max(score) maxs from exam_record a,examination_info b
    where a.exam_id=b.exam_id
    and b.tag='SQL'
    and b.difficulty='hard'
)