题解 | #月总刷题数和日均刷题数#

(
  select
    date_format(submit_time, '%Y%m') submit_month,
    count(*) month_q_cnt,
    round(count(*) / day(last_day(min(submit_time))), 3) avg_day_q_cnt
  from
    practice_record
  where
    year(submit_time) = 2021
  group by
    submit_month
  order by
    submit_month
  limit
    1000
)
union all
select
  '2021汇总',
  count(*) month_q_cnt,
  round(count(*) / 31, 3) avg_day_q_cnt
from
  practice_record
where
  year(submit_time) = 2021