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. >> >
