拼多多数据分析8.28一面
热乎的面经
po主背景:211本硕,本统计,硕金融。面试总时长55分钟
1. 自我介绍2minutes
2. 简历上的一个项目,商品标签效果分析30minutes(反复提出相似案例,比如样本方差很大怎么办,多个标签怎么办,考验知识储备水平)
3. sql题:商品上下架时间表,goods_id,Type(online:上架、offline:下架),log_time的形式
通过sql变成goods_id,online_time,offline_time
4. 反问
题主是被面试官引导着做出来了,面试现场脑子短路.....估计凉了
附上sql代码~(回忆的,可能有错误?)
select goods_id ,a.log_time as online_time ,b.log_time as offline_time from (select * ,row_number() over(partition by goods_id order by log_time) as r1 from Log where Type = 'Online') a left join (select * ,row_number() over(partition by goods_id order by log_time) as r2 from Log where Type = 'Offline') b on a.goods_id =b.goods_id and a.r1=b.r2