题解 | #0级用户高难度试卷的平均用时和平均得分#
0级用户高难度试卷的平均用时和平均得分
https://www.nowcoder.com/practice/bb474c6cbd77478fb6d9fc86934d0ebb
这道题也简单的,贴个代码
主要的坑:就是如果用户没做完试卷【即submit_time为null】,就要用这个试卷的duration代替
select re.uid, round(avg(IFNULL(re.score,0)),0) avg_score, round(avg(ifnull(timestampdiff(minute, start_time, submit_time), info.duration)),1) avg_time_took from exam_record re left join user_info uinfo using(uid) left join examination_info info using(exam_id) where uinfo.level = 0 and difficulty = 'hard' GROUP BY uid