题解 | #SQL类别高难度试卷得分的截断平均值#
SQL类别高难度试卷得分的截断平均值
http://www.nowcoder.com/practice/a690f76a718242fd80757115d305be45
select tag, difficulty, round((sum(score)-max(score)-min(score))/(count(score)-2),1) as clip_avg_score FROM( exam_record as er left join examination_info as ei on er.exam_id = ei.exam_id ) where tag = 'SQL' and difficulty = 'hard'