题解 | 作答试卷得分大于过80的人的用户等级分布
# 步骤分析: # 作答SQL试卷的用户 # 得分在80分以上 # 用户等级分组统计人数,降序排序 SELECT u.level, COUNT(DISTINCT er.uid) AS level_cnt FROM exam_record AS er LEFT OUTER JOIN examination_info AS ei ON er.exam_id = ei.exam_id LEFT OUTER JOIN user_info AS u ON er.uid = u.uid WHERE ei.tag = 'SQL' AND er.score > 80 GROUP BY u.level ORDER BY level_cnt DESC, level DESC;