HiveSQL-面试题028 用户中两人一定认识的组合数

数据仓库晨曦

发布于 2024-01-08 15:46:03

1240

发布于 2024-01-08 15:46:03

文章被收录于专栏：数据仓库技术数据仓库技术

一、题目

有某城市网吧上网记录表，包含字段：网吧id，访客id（身份证号），上线时间，下线时间。

规则1：如果两个用户在同一个网吧上线时间或者下线时间间隔在10分钟以内，则两个用户可能认识；
规则2：如果两个用户在三家以上的网吧出现过【规则1】可能认识的情况，则两人一定认识；

请计算该市中两人一定认识的组合数

+---------+----------+----------------------+----------------------+
| bar_id  | user_id  |      login_time      |     logoff_time      |
+---------+----------+----------------------+----------------------+
| 1       | 001      | 2023-08-01 09:00:00  | 2023-08-01 10:00:00  |
| 1       | 003      | 2023-08-01 09:04:00  | 2023-08-01 11:00:00  |
| 2       | 004      | 2023-08-01 10:00:00  | 2023-08-01 12:02:00  |
| 1       | 006      | 2023-08-01 10:00:00  | 2023-08-01 12:00:00  |
| 2       | 005      | 2023-08-01 10:10:00  | 2023-08-01 11:00:00  |
| 2       | 001      | 2023-08-01 11:01:00  | 2023-08-01 12:00:00  |
| 2       | 002      | 2023-08-01 11:03:00  | 2023-08-01 14:00:00  |
| 3       | 002      | 2023-08-02 15:00:00  | 2023-08-02 17:06:00  |
| 3       | 001      | 2023-08-02 16:01:00  | 2023-08-02 17:07:00  |
| 3       | 004      | 2023-08-02 16:02:00  | 2023-08-02 18:00:00  |
| 3       | 003      | 2023-08-02 20:00:00  | 2023-08-02 22:00:00  |
| 4       | 001      | 2023-08-03 17:00:00  | 2023-08-03 19:00:00  |
| 4       | 002      | 2023-08-03 18:00:00  | 2023-08-03 21:00:00  |
| 4       | 003      | 2023-08-03 18:05:00  | 2023-08-03 22:00:00  |
| 4       | 004      | 2023-08-03 19:00:00  | 2023-08-03 18:58:00  |
+---------+----------+----------------------+----------------------+

二、分析

1.首先计算可能认识的人，由于所有可能认识的条件必须发生在同一个网吧内，以bar_id进行自关联，然后id要求t1>t2来保证同一个用户和其他的用户只进行一次关联，限定上线时间或者下线时间在10分钟内；

2.计算出可能认识的用户组中，出现的网吧个数；

3.计算网吧个数>=3的组合数；

维度	评分
题目难度	⭐️⭐️⭐️
题目清晰度	⭐️⭐️⭐️⭐️⭐️
业务常见度	⭐️⭐️⭐️

三、SQL

1）可能认识的记录

select 
t1.bar_id,
t1.user_id,
t1.login_time,
t1.logoff_time,
t2.bar_id,
t2.user_id,
t2.login_time,
t2.logoff_time
from
(
select bar_id,user_id,login_time,logoff_time from t_netbar_028
) t1
join
(
select bar_id,user_id,login_time,logoff_time from t_netbar_028
) t2
on t1.bar_id = t2.bar_id
where t1.user_id <t2.user_id --限定t1的user_id <t2的user_id，防止重复关联和自关联
and
(
abs(unix_timestamp(t1.login_time,'yyyy-MM-dd HH:mm:ss') -unix_timestamp(t2.login_time,'yyyy-MM-dd HH:mm:ss') ) < 600-- 上线时间在10min内
or
abs(unix_timestamp(t1.logoff_time,'yyyy-MM-dd HH:mm:ss') -unix_timestamp(t2.logoff_time,'yyyy-MM-dd HH:mm:ss') )<600 -- 下线时间在10min内
)

查询结果

2)按照t1的user_id、t2的user_id 进行分组，统计网吧ID个数

select 
user_id1,
user_id2,
count(distinct bar_id) as bar_num
from
(
select 
t1.bar_id,
t1.user_id as user_id1,
t2.user_id as user_id2
from
(
select bar_id,user_id,login_time,logoff_time from t_netbar_028
) t1
join
(
select bar_id,user_id,login_time,logoff_time from t_netbar_028
) t2
on t1.bar_id = t2.bar_id
where t1.user_id <t2.user_id --限定t1的user_id <t2的user_id，防止重复关联和自关联
and
(
abs(unix_timestamp(t1.login_time,'yyyy-MM-dd HH:mm:ss') -unix_timestamp(t2.login_time,'yyyy-MM-dd HH:mm:ss') ) < 600-- 上线时间在10min内
or
abs(unix_timestamp(t1.logoff_time,'yyyy-MM-dd HH:mm:ss') -unix_timestamp(t2.logoff_time,'yyyy-MM-dd HH:mm:ss') )<600 -- 下线时间在10min内
)
)t
group by user_id1,user_id2

查询结果

3)统计最终结果

select count(1) as group_nums
from 
(select 
user_id1,
user_id2,
count(distinct bar_id) as bar_num
from
(
select 
t1.bar_id,
t1.user_id as user_id1,
t2.user_id as user_id2
from
(
select bar_id,user_id,login_time,logoff_time from t_netbar_028
) t1
join
(
select bar_id,user_id,login_time,logoff_time from t_netbar_028
) t2
on t1.bar_id = t2.bar_id
where t1.user_id <t2.user_id --限定t1的user_id <t2的user_id，防止重复关联和自关联
and
(
abs(unix_timestamp(t1.login_time,'yyyy-MM-dd HH:mm:ss') -unix_timestamp(t2.login_time,'yyyy-MM-dd HH:mm:ss') ) < 600-- 上线时间在10min内
or
abs(unix_timestamp(t1.logoff_time,'yyyy-MM-dd HH:mm:ss') -unix_timestamp(t2.logoff_time,'yyyy-MM-dd HH:mm:ss') )<600 -- 下线时间在10min内
)
)t
group by user_id1,user_id2
)tt
where bar_num >=3

查询结果

四、建表语句和数据插入

--建表语句
CREATE TABLE t_netbar_028 (
bar_id bigint COMMENT '网吧ID',
user_id string COMMENT '用户ID',
login_time string COMMENT '上线时间',
logoff_time string COMMENT '下线时间'
) COMMENT '网吧上下线记录表'
ROW FORMAT DELIMITED FIELDS TERMINATED BY '\t' 
;
-- 插入数据
insert into t_netbar_028(bar_id,user_id,login_time,logoff_time)
values
(1,'001','2023-08-01 09:00:00','2023-08-01 10:00:00'),
(2,'001','2023-08-01 11:01:00','2023-08-01 12:00:00'),
(2,'002','2023-08-01 11:03:00','2023-08-01 14:00:00'),
(3,'001','2023-08-02 16:01:00','2023-08-02 17:07:00'),
(3,'002','2023-08-02 15:00:00','2023-08-02 17:06:00'),
(4,'001','2023-08-03 17:00:00','2023-08-03 19:00:00'),
(4,'002','2023-08-03 18:00:00','2023-08-03 21:00:00'),
(1,'003','2023-08-01 09:04:00','2023-08-01 11:00:00'),
(3,'003','2023-08-02 20:00:00','2023-08-02 22:00:00'),
(4,'003','2023-08-03 18:05:00','2023-08-03 22:00:00'),
(2,'004','2023-08-01 10:00:00','2023-08-01 12:02:00'),
(3,'004','2023-08-02 16:02:00','2023-08-02 18:00:00'),
(4,'004','2023-08-03 19:00:00','2023-08-03 18:58:00'),
(2,'005','2023-08-01 10:10:00','2023-08-01 11:00:00'),
(1,'006','2023-08-01 10:00:00','2023-08-01 12:00:00')

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原始发表：2023-08-08，如有侵权请联系 cloudcommunity@tencent.com 删除

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