题解 | #2021年11月每天的人均浏览文章时长#

with t1 as(select  *,DATE(out_time) as dt,TIMESTAMPDIFF(second,in_time,out_time)as time from tb_user_log
where DATE_FORMAT(out_time,'%Y-%m')='2021-11' and artical_id	<>0) 
select dt,round(sum(time)/count(distinct uid),1) as avg_viiew_len_sec from t1 
group by dt order by avg_viiew_len_sec