题解 | #试卷发布当天作答人数和平均分#
试卷发布当天作答人数和平均分
https://www.nowcoder.com/practice/5b58e89556dc4153a79d8cf8c08ba499
select exam_id,
count(distinct uid) as uv,
round(avg(score),1) as avg_score
from exam_record
where (exam_id,date(start_time)) in (
select exam_id,date(release_time)
from examination_info
where tag = 'SQL'
)
and uid in(
select uid
from user_info
where level > 5
)
group by exam_id
order by uv desc,avg_score asc
#现在做这些题都是对一半多，总有关键的地方想不到
