[ 
https://issues.apache.org/jira/browse/ARROW-12710?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17359401#comment-17359401
 ] 

Niranda Perera commented on ARROW-12710:
----------------------------------------

[~icook] I checked the postgres string_agg 
(https://www.postgresqltutorial.com/postgresql-aggregate-functions/postgresql-string_agg-function/).
 It seems to have an `order_by` option. Do you we need that part as well? If 
not, AFAIU, this would be a straight-forward scalar agg kernel, and I can take 
it up. :)

> [C++] String concatenate aggregate kernel
> -----------------------------------------
>
>                 Key: ARROW-12710
>                 URL: https://issues.apache.org/jira/browse/ARROW-12710
>             Project: Apache Arrow
>          Issue Type: New Feature
>          Components: C++
>            Reporter: Ian Cook
>            Priority: Major
>
> Like MySQL/Impala {{group_concat}} and PostgreSQL {{string_agg}}. Takes a 
> string array and a separator (possibly optional?) and returns one scalar 
> string (one per group in the case of group aggregation) representing all the 
> string values in the array concatenated together, with the separator added 
> between each pair of concatenated values.
> For example, in the case of no grouping and using separator {{"-"}}, this 
> would take input:
> {code}
> Array<string>
> [ 
>   "foo",
>   "bar",
>   "baz"
> ]
> {code}
> and return the following string scalar as output:
> {code}
> "foo-bar-baz"
> {code}
>  



--
This message was sent by Atlassian Jira
(v8.3.4#803005)

Reply via email to