题解 | #筛选限定昵称成就值活跃日期的用户#

我觉得这个应该是对的，加了group by ui和max（）来确定最近的一次活跃时间。

虽然不加这个也能够提交通过。

select uid,
       nick_name,
       achievement
from user_info
where nick_name like '牛客%号'
and achievement between 1200 and 2500
and (
    uid in(
        select uid
        from exam_record
        group by uid
        having date_format(max(start_time), '%Y%m') = '202109')
    or uid in(
        select uid
        from practice_record
        group by uid
        having date_format(max(submit_time), '%Y%m') = '202109')
)