题解 | #广告点击的高峰期#
广告点击的高峰期
https://www.nowcoder.com/practice/6756d65784f9413b8505c1d0c6754b3a
select click_hour, click_cnt from (select hour(click_time) click_hour, count(trace_id) click_cnt, rank() over (order by count(trace_id) desc) click_rank from user_ad_click_time group by hour(click_time)) as t where click_rank = 1 ;