题解 | #分别满足两个活动的人#

select
    uid,
    "activity1" as activity
from
    exam_record
where
    year (submit_time) = 2021
group by
    uid
having
    min(score) >= 85
union
select
    uid,
    "activity2" as activity
from
    exam_record
    join examination_info on examination_info.exam_id = exam_record.exam_id
where
    timestampdiff (
        second,
        exam_record.start_time,
        exam_record.submit_time
    ) < examination_info.duration * 60 / 2
    and examination_info.difficulty = 'hard'
    and exam_record.score > 80
order by
    uid

还能这样写啊