Hi Guys, @Ingo Bürk <i...@ververica.com> Thanks for that, but I need this function sooner rather than later. Would be happy to contribute it back once I get it to work :) @Caizhi Weng <tsreape...@gmail.com> The gist was not in the correct version. I can't return an Array[T] since it will always be an Array[Object] at runtime, and that's not what I want. I'm actually returning ArrayData (more specifically, a GenericArrayData). But for GenericArrayData the type of the array must be an internal one, and not external. In order to do this, I need access to something like DataStructureConverters <https://github.com/apache/flink/blob/master/flink-table/flink-table-runtime/src/main/java/org/apache/flink/table/data/conversion/DataStructureConverters.java> but I can't calculate the type at runtime, I'd need this injected somehow in the TypeInference stage.
On Tue, Aug 24, 2021 at 9:38 AM Ingo Bürk <i...@ververica.com> wrote: > Hi, > > just FYI, we do already have issues in JIRA for this: > * https://issues.apache.org/jira/browse/FLINK-21949 > * https://issues.apache.org/jira/browse/FLINK-22484 > > > Best > Ingo > > On Tue, Aug 24, 2021 at 8:23 AM Caizhi Weng <tsreape...@gmail.com> wrote: > >> Hi! >> >> As far as I know, returning an array from the getValue method containing >> external data format is OK. Flink will do the conversion for you. >> >> Are you faced with any exception when using this array_agg? If yes what's >> the exception stack? >> >> You can also open a JIRA ticket to require a built-in support for >> array_agg, as this function exists in many data ware houses. >> >> Yuval Itzchakov <yuva...@gmail.com> 于2021年8月23日周一 下午7:38写道： >> >>> Hi, >>> >>> I'm trying to implement a generic ARRAY_AGG UDF function (identical to >>> the one that exists in many data WHs, e.g >>> https://docs.snowflake.com/en/sql-reference/functions/array_agg.html) >>> to utilize in Flink SQL. >>> >>> Taking reference from CollectAggFunction >>> <https://github.com/apache/flink/blob/master/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/functions/aggfunctions/CollectAggFunction.java>, >>> I tried using ArrayData to generate a GenericArrayData as an output type. >>> The problem with is I need a way to convert from the external format being >>> used in the UDF (e.g String, Integer) to the internal representation >>> required by Flink (i.e. StringData). I haven't found a straight way of >>> going about that. >>> >>> Here is a gist of the implementation >>> <https://gist.github.com/YuvalItzchakov/5cc7b076d31d73e5c1f9b7b72b3c624b> >>> . >>> Would appreciate any help on how to tackle this. >>> >>> -- >>> Best Regards, >>> Yuval Itzchakov. >>> >> -- Best Regards, Yuval Itzchakov.
