题解 | #SQL类别高难度试卷得分的截断平均值#

# select tag,difficulty,
# 	round((sum(score)-max(score)-min(score))/(count(score)-2),1) clip_avg_score
# from(
# 	select tag,difficulty,score
# 	from examination_info i inner join exam_record r
# 	    on i.exam_id = r.exam_id
# 	    and tag = 'SQL' 
# 	    and difficulty = 'hard'
# 	    and score is not null
# 	order by score
# 	) as sub;

select tag,difficulty,
	round((sum(score)-max(score)-min(score))/(count(score)-2),1) clip_avg_score
from examination_info i inner join exam_record r
on i.exam_id = r.exam_id
and tag = 'SQL' 
and difficulty = 'hard'
and score is not null;