Hive将数据选择为结构数组

Question

我试图找出一种方法在Hive中从平面源中选择数据并输出到一个名为struct的数组中.这是我正在寻找的一个例子......

样本数据:

house_id,first_name,last_name
1,bob,jones
1,jenny,jones
2,sally,johnson
3,john,smith
3,barb,smith

期望的输出:

1   [{"first_name":"bob","last_name":"jones"},{"first_name":"jenny","last_name":"jones"}]
2   [{"first_name":"sally","last_name":"johnson"}]
3   [{"first_name":"john","last_name":"smith"},{"first_name":"barb","last_name":"smith"}]

我尝试了collect_list和collect_set,但它们只允许原始数据类型.有关如何在Hive中进行此操作的任何想法？

Answer 1

我会使用这个jar,它是一个更好的实现collect(并采用复杂的数据类型).

查询:

add jar /path/to/jar/brickhouse-0.7.1.jar;
create temporary function collect as 'brickhouse.udf.collect.CollectUDAF';

select house_id
  , collect(named_struct("first_name", first_name, "last_name", last_name))
from db.table
group by house_id

输出:

1   [{"first_name":"bob","last_name":"jones"}, {"first_name":"jenny","last_name":"jones"}]
2   [{"first_name":"sally","last_name":"johnson"}]
3   [{"first_name":"john","last_name":"smith"},{"first_name":"barb","last_name":"smith"}]