题解
每天的日活数及新用户占比
http://www.nowcoder.com/practice/dbbc9b03794a48f6b34f1131b1a903eb
with t as (select distinct uid,left(in_time,10) date from tb_user_log union select distinct uid,left(out_time,10) date from tb_user_log order by date) #查出每天都有哪些用户活跃(去重) select t.date dt, count() dau, round( sum( case when (t.uid,t.date) in (select uid,left(min(date(in_time)),10) from tb_user_log group by uid) then 1 else 0 end ) /count(), 2) uv_new_ratio FROM t group by t.date order by t.date