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 tag
,count(start_time) AS tag_cnt
from exam_record er
inner join examination_info ei
on er.exam_id = ei.exam_id
where uid in(
select uid
from exam_record
where month(submit_time) = 9
group by uid
having count(submit_time)>=3
)
group by tag
order by tag_cnt desc
连接作答信息表和试卷信息表，选择字段tag和开始作答时间（为了统计作答次数），限制用户uid是提交次数不少于3次的用户
投递平安产险科技中心等公司6个岗位
