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Xingcan Cui edited comment on FLINK-8863 at 5/19/18 5:04 PM: ------------------------------------------------------------- Hi [~twalthr], I got two questions during the implementation. 1. Why {{org.apache.flink.table.api.TableEnvironment}} only exposes a {{registerFunction()}} method for {{ScalarFunction}}? 2. Shall we add a hierarchy depth restriction for the parameters of a UDF constructor? was (Author: xccui): Hi [~twalthr], I got two questions during the implementation. 1. Why {{org.apache.flink.table.api.TableEnvironment}} only exposes a {{registerFunction()}} method for {{ScalarFunction}}s? 2. Shall we add a hierarchy depth restriction for the parameters of a UDF constructor? > Add user-defined function support in SQL Client > ----------------------------------------------- > > Key: FLINK-8863 > URL: https://issues.apache.org/jira/browse/FLINK-8863 > Project: Flink > Issue Type: Sub-task > Components: Table API & SQL > Reporter: Timo Walther > Assignee: Xingcan Cui > Priority: Major > > This issue is a subtask of part two "Full Embedded SQL Client" of the > implementation plan mentioned inĀ > [FLIP-24|https://cwiki.apache.org/confluence/display/FLINK/FLIP-24+-+SQL+Client]. > It should be possible to declare user-defined functions in the SQL client. > For now, we limit the registration to classes that implement > {{ScalarFunction}}, {{TableFunction}}, {{AggregateFunction}}. Functions that > are implemented in SQL are not part of this issue. > I would suggest to introduce a {{functions}} top-level property. The > declaration could look similar to: > {code} > functions: > - name: testFunction > from: class <-- optional, default: class > class: org.my.MyScalarFunction > constructor: <-- optional, needed for > certain types of functions > - 42.0 > - class: org.my.Class <-- possibility to create > objects via properties > constructor: > - 1 > - true > - false > - "whatever" > - type: INT > value: 1 > {code} -- This message was sent by Atlassian JIRA (v7.6.3#76005)