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 ei.tag, ei.difficulty, ROUND( (SUM(er.score) - (MAX(er.score) + MIN(er.score))) / (COUNT(er.score) - 2), 1 ) clip_avg_score FROM examination_info ei INNER JOIN exam_record er ON ei.tag = 'SQL' AND ei.difficulty = 'hard' AND ei.exam_id = er.exam_id GROUP BY ei.tag, ei.difficulty;
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