Yes I think Calcite does not support varargs in for scalar function (so in
UDF). Please check this JIRA:
https://issues.apache.org/jira/browse/CALCITE-2772
-Rui
On Tue, Jan 26, 2021 at 2:04 AM Niels Basjes <ni...@basjes.nl> wrote:
> Hi,
>
> I want to define a Beam SQL user defined function that accepts a variable
> list of arguments (which may be empty).
>
> What I essentially would like to have is
>
> public class ParseUserAgentJson implements BeamSqlUdf {
>
> public static String eval( String input,
> String... fields) { ... }
>
> }
>
> When I do this I get this on the case where the list is empty
>
> *Caused by:
> org.apache.beam.vendor.calcite.v1_20_0.org.apache.calcite.sql.validate.SqlValidatorException:
> No match found for function signature ParseUserAgentJson(<CHARACTER>)*
> * at
> java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native
> Method)*
> * at
> java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)*
> * at
> java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)*
> * at
> java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:490)*
>
>
> So I tried
> public static String eval( @Parameter(name = "userAgent") String input,
>
> @Parameter(name = "Fields", optional = true)
> String ... fields
> )
>
> Which gives
>
>
> *java.lang.AssertionError: No assign rules for OTHER defined*
>
> * at
> org.apache.beam.vendor.calcite.v1_20_0.org.apache.calcite.sql.type.SqlTypeAssignmentRules.canCastFrom(SqlTypeAssignmentRules.java:389)*
> * at
> org.apache.beam.vendor.calcite.v1_20_0.org.apache.calcite.sql.type.SqlTypeUtil.canCastFrom(SqlTypeUtil.java:864)*
> * at
> org.apache.beam.vendor.calcite.v1_20_0.org.apache.calcite.sql.SqlUtil.lambda$filterRoutinesByParameterType$4(SqlUtil.java:620)*
>
>
> It seems this is Calcite that is unable to do the "Variable arguments"
> trick.
>
> So right now I have this workaround which works but limits it to a maximum
> of 10 arguments:
>
> public static String eval( // NOSONAR java:S107 Methods should not have
> too many parameters
>
> @Parameter(name = "userAgent") String input,
> @Parameter(name = "Field 1", optional = true) String field1,
> @Parameter(name = "Field 2", optional = true) String field2,
> @Parameter(name = "Field 3", optional = true) String field3,
> @Parameter(name = "Field 4", optional = true) String field4,
> @Parameter(name = "Field 5", optional = true) String field5,
> @Parameter(name = "Field 6", optional = true) String field6,
> @Parameter(name = "Field 7", optional = true) String field7,
> @Parameter(name = "Field 8", optional = true) String field8,
> @Parameter(name = "Field 9", optional = true) String field9,
> @Parameter(name = "Field 10", optional = true) String field10
> ) {
>
>
> My question: Is there a better way to do this?
>
> --
> Best regards / Met vriendelijke groeten,
>
> Niels Basjes
>
