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
select
uid,
round(sum(score)/count(uid),0) as avg_score,
round(sum(if(submit_time is null,duration,timestampdiff(minute,start_time,submit_time)))/count(uid),1)
from
exam_record
join user_info using (uid)
join examination_info using (exam_id)
where
difficulty = 'hard'
and level = 0
group by uid
本题难度在于，对于未完成的试卷应该是选择它的examination_info中的duration属性进行选择判断。
