题解 | 月均完成试卷数不小于3的用户爱作答的类别
月均完成试卷数不小于3的用户爱作答的类别
https://www.nowcoder.com/practice/b1d13efcfa0c4ecea517afbdb9090845
select i.tag tag, count(r.id) tag_cnt
from exam_record r
left join examination_info i
on r.exam_id = i.exam_id
where r.uid in (
select uid from exam_record
where submit_time is not null
group by uid, month(submit_time)
having count(*) >= 3
)
group by tag
order by tag_cnt desc
