I don't know of anything like what you want atleast until Hive 0.11.
However, you could try something like this:
INSERT OVERWRITE TABLE rollup
SELECT id, start_time, collect_set(concat_ws(",", objects.name,
objects.value, objects.type)) AS product_details
FROM bar
GROUP BY id, start_time;
It's a bit hacky, but it does the trick. It basically concats all the
objects you care about in a string, and then collects a set of that. Then,
when you want to extract a field from the "product_details" array, just do
this (say you want to extract the very first product's name in each array):
SELECT SPLIT(a[0].product_details)[0] AS first_name FROM rollup a;
Hope that helps!
Best Regards,
Nishant Kelkar
On Wed, Sep 3, 2014 at 1:47 PM, anusha Mangina <anusha.mang...@gmail.com>
wrote:
> I have a table defined as:
>
> CREATE TABLE foo (
> id INT,
> start_time STRING,
> name STRING,
> value STRING,
> type STRING
> )
>
> The 'name', 'value' and 'type' fields actually describe another object, and
> I'd like to turn these into STRUCTs, something like:
>
> CREATE TABLE bar (
> id INT,
> start_time STRING,
> object STRUCT<name: STRING,
> value: STRING,
> type: STRING>
> )
>
> However, I'd also like to create a rollup table containing the most recent
> result for a given 'id' field. There can be multiple different 'object'
> structs for a given combination of 'id' and 'start_time', so I thought I'd
> turn this into an array of structs. My ideal rollup table would look like:
>
> CREATE TABLE rollup (
> id INT,
> start_time STRING,
> objects ARRAY<STRUCT<name: STRING,
> value: STRING,
> type: STRING>>
> )
>
> However, I can't do this because the following query fails:
>
> INSERT OVERWRITE TABLE rollup
> SELECT id, start_time, collect_set(object)
> FROM bar
> GROUP BY id, start_time
>
> Here's the error I get:
>
> FAILED: UDFArgumentTypeException Only primitive type arguments are accepted
> but struct<name:string,value:string,type:string> was passed as parameter 1.
>
> Is there any way I can do this?
>
>
