题解 | #21年8月份练题总数#

#1.2021年8月份 year(date)='2021' and month(date)='8'
#2.总用户数 count(dinstic device_id)
#3.总练习次数 count(question_id)
select 
    count(distinct device_id) as did_cnt,
    count(question_id) as question_cnt
from question_practice_detail as qpd
where year(qpd.date)='2021' and month(qpd.date)='8'

#1.2021年8月份 year(date)='2021' and month(date)='8'

#2.总用户数 count(dinstic device_id)

#3.总练习次数 count(question_id)