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

几乎都做不起，我感觉自己都想放弃了