寻找前5大区域和区域内的价格找到前5名客户。 （蜂巢）

Question

我们有一个要求，我们希望通过它们的价格总和找到前N个区域，然后找到每个区域的前N个客户。

示例数据。

REGION_NAME,CUSTOMER_NAME,PRICE

RG1,Customer1,100
RG1,Customer2,200
RG1,Customer3,100
RG2,Customer4,100
RG2,Customer5,200
RG2,Customer6,400
RG3,Customer7,100
RG3,Customer8,200
RG3,Customer9,500
RG3,Customer9,200

假设我们希望通过汇总价格

来获得每个地区的前2名和前2名客户

Region_name，Region_sum，Customer_name，Customer_price（Sum）

 RG3,1000,Customer9,700 (Sum of customer price)
 RG3,1000,Customer8,200
 RG2,700,Customer6,400
 RG2,700,customer5,200  

如何为此编写HIVE查询？我们无法想到如何使用HIVE来写这个。我们可能要编写MapReduce或PIG？

Answer 1

您可以使用分析功能和自我加入在Hive中执行此操作：

select regions_ranked.region_name, regions_ranked.region_sum, customers_ranked.customer_name, customers_ranked.customer_sum from
(
  select region_name, customer_name, customer_sum, rank() over (partition by region_name order by customer_sum desc) as customer_rank from (
    select region_name, customer_name, sum(price) as customer_sum
    from foo group by region_name, customer_name
  ) customers_sum
) customers_ranked
join
(
  select region_name, region_sum, rank() over (order by region_sum desc) as region_rank from (
    select region_name, sum(price) as region_sum
    from foo group by region_name
  ) regions_sum
) regions_ranked
on customers_ranked.region_name = regions_ranked.region_name
where region_rank <= 2 and customer_rank <= 2;

这给出了您正在寻找的确切输出，尽管不按顺序排列。您可以通过＆＃34;进行排序。如果你想要的话，最后一句。