题解 | #SQL类别高难度试卷得分的截断平均值#

SELECT tag, difficulty, clip_avg_score
FROM
    (SELECT e1.exam_id, ROUND(AVG(score),1) clip_avg_score
    FROM exam_record e1
    LEFT JOIN (
        SELECT exam_id,MIN(score) min_score, MAX(score) max_score
        FROM exam_record
        GROUP BY exam_id
        ) e2 
    ON e2.exam_id = e1.exam_id
    WHERE score > min_score AND score < max_score
    GROUP BY  e1.exam_id
    )t1 
LEFT JOIN examination_info t2 
ON t1.exam_id = t2.exam_id

感觉是最笨得方法了