题解 | #作答试卷得分大于过80的人的用户等级分布#
作答试卷得分大于过80的人的用户等级分布
http://www.nowcoder.com/practice/5bc77e3a3c374ad6a92798f0ead4c744
SELECT ui.level,COUNT(ui.uid) AS level_cnt FROM user_info ui JOIN exam_record er ON ui.uid=er.uid WHERE er.exam_id IN (SELECT exam_id FROM examination_info WHERE tag='SQL') AND er.score> 80 GROUP BY ui.level ORDER BY level_cnt DESC;
题目很简单,不难,慢慢做,捋清楚。