Hi to all,
I'd like to join 2 datasets of POJO, let's say for example:
Person:
- name
- birthPlaceId
Place:
- id
- name
I'd like to do
people.coCoGroup(places).where("birthPlaceId").equalTo("id").with(...)
However, not all people have a birthPlaceId value in my use case..so I get
a NullPointer.
Am I using the wrong operator for this?
This is the stackTrace:
java.lang.RuntimeException: A NullPointerException occured while accessing
a key field in a POJO. Most likely, the value grouped/joined on is null.
Field name: birthPlaceId
at
org.apache.flink.api.java.typeutils.runtime.PojoComparator.hash(PojoComparator.java:217)
at
org.apache.flink.runtime.operators.shipping.OutputEmitter.hashPartitionDefault(OutputEmitter.java:175)
at
org.apache.flink.runtime.operators.shipping.OutputEmitter.selectChannels(OutputEmitter.java:132)
at
org.apache.flink.runtime.operators.shipping.OutputEmitter.selectChannels(OutputEmitter.java:28)
at
org.apache.flink.runtime.io.network.api.writer.RecordWriter.emit(RecordWriter.java:78)
at
org.apache.flink.runtime.operators.shipping.OutputCollector.collect(OutputCollector.java:65)
Best,
Flavio
