已知顾客拜访店铺的拜访日志
| user_id | shop |
|---|
| u1 | a |
| u2 | b |
| u1 | b |
| u1 | a |
| u3 | c |
| u4 | b |
| u1 | a |
| u2 | c |
| u5 | b |
| u4 | b |
| u6 | c |
| u2 | c |
| u1 | b |
| u2 | a |
| u2 | a |
| u3 | a |
| u5 | a |
| u5 | a |
| u5 | a |
建表、导表
create table visit(user_id string,shop string) row format delimited fields terminated by '\t';load data local inpath '/data/visit.dat' into table visit;
求每个店铺的UV（访客数）
select shop , count(distinct user_id) as uv from visit group by shop;
求每个店铺拜访次数top3的访客信息。输入店铺名称、访客id、拜访次数
1.先求出每个店铺，每个访客的拜访次数
select shop, user_id, count(*) as ct from visit group by shop, user_id;
| shop | user_id | ct |
|---|
| a | u1 | 3 |
| b | u1 | 2 |
| a | u2 | 2 |
| b | u2 | 1 |
| c | u2 | 2 |
| a | u3 | 1 |
| c | u3 | 1 |
| b | u4 | 2 |
| a | u5 | 3 |
| b | u5 | 1 |
| c | u6 | 1 |
2.计算每个店铺被用户拜访次数排名
select shop,user_id,ct,rank() over(partition by shop order by ct) rkfrom (select shop, user_id, count(*) as ct from visit group by shop, user_id) as t1;
| shop | user_id | ct | rk |
|---|
| a | u3 | 1 | 1 |
| a | u2 | 2 | 2 |
| a | u5 | 3 | 3 |
| a | u1 | 3 | 3 |
| b | u5 | 1 | 1 |
| b | u2 | 1 | 1 |
| b | u4 | 2 | 3 |
| b | u1 | 2 | 3 |
| c | u6 | 1 | 1 |
| c | u3 | 1 | 1 |
| c | u2 | 2 | 3 |
3.取每个店铺的前三名
select shop, user_id, ct from(select shop,user_id,ct,rank() over(partition by shop order by ct) rkfrom (select shop, user_id, count(*) as ct from visit group by shop, user_id) as t1) as t2 where rk <= 3;
| shop | user_id | ct |
|---|
| a | u3 | 1 |
| a | u2 | 2 |
| a | u1 | 3 |
| a | u5 | 3 |
| b | u2 | 1 |
| b | u5 | 1 |
| b | u1 | 2 |
| b | u4 | 2 |
| c | u3 | 1 |
| c | u6 | 1 |
| c | u2 | 2 |
The End