题解 | 未下单用户登陆渠道统计
未下单用户登陆渠道统计
https://www.nowcoder.com/practice/5090553d7854458987997a5c91c30975
select channel, count(1) as cnt from user_info a left join order_log b on a.uid=b.uid where b.uid is null group by channel order by cnt desc, channel limit 1