sam lin created FLINK-19196: ------------------------------- Summary: FlinkSQL aggregation function to aggregate array typed column to Map/Multiset Key: FLINK-19196 URL: https://issues.apache.org/jira/browse/FLINK-19196 Project: Flink Issue Type: New Feature Components: Table SQL / API Affects Versions: 1.11.1 Reporter: sam lin
Hi, For FlinkSQL, how do I aggregate an array typed column to a Map/Multiset type? e.g. Given the source events: userID, arr_types 1, [a, b] 2, [a] 1, [b, c] ``` SELECT userID, collect_arr(arr_types) FROM src_table GROUP BY userID ``` Using the above SQL could produce results like: 1, \{a: 1, b: 2, c:1} 2, \{a: 1} My question is do we have existing UDF to do that? If not, what is the recommended way to achieve this? I'm happy to write a UDF if you could provide some code pointers. Thanks in advance! -- This message was sent by Atlassian Jira (v8.3.4#803005)