Only a single expression in the SELECT clause is supported with UDTF's

[Tim Robertson]

Hi all,

I am trying my first UDTF, but can't seem to get it to run.  Can
anyone spot anything wrong with this please:

hive> select taxonDensityUDTF(kingdom_concept_id, phylum_concept_id)
as p,k from temp_kingdom_phylum;
FAILED: Error in semantic analysis: Only a single expression in the
SELECT clause is supported with UDTF's
hive>

Below is my code.  Thanks for any pointers,

Tim



@description(
                  name = "taxonDensityUDTF",
                  value = "_FUNC_(kingdom_concept_id, phylum_concept_id)"
                )
public class TaxonDensityUDTF extends GenericUDTF {
        Integer kingdom_concept_id = Integer.valueOf(0);
        Integer phylum_concept_id = Integer.valueOf(0);
        
        /**
         * @see org.apache.hadoop.hive.ql.udf.generic.GenericUDTF#close()
         */
        @Override
        public void close() throws HiveException {
                Object[] forwardObj = new Object[2];
                forwardObj[0] = kingdom_concept_id;
                forwardObj[1] = phylum_concept_id;
                forward(forwardObj);
                // TEST STUFF FOR NOW
                forwardObj = new Object[2];
                forwardObj[0] = kingdom_concept_id+1;
                forwardObj[1] = phylum_concept_id+1;
                forward(forwardObj);            
        }

        /**
         * @see 
org.apache.hadoop.hive.ql.udf.generic.GenericUDTF#initialize(org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector[])
         */
        @Override
        public StructObjectInspector initialize(ObjectInspector[] arg0)
throws UDFArgumentException {
                ArrayList<String> fieldNames = new ArrayList<String>();
                ArrayList<ObjectInspector> fieldOIs = new 
ArrayList<ObjectInspector>();
                fieldNames.add("kingdom_concept_id");
                fieldNames.add("phylum_concept_id");
                
fieldOIs.add(PrimitiveObjectInspectorFactory.javaIntObjectInspector);
                
fieldOIs.add(PrimitiveObjectInspectorFactory.javaIntObjectInspector);
                return 
ObjectInspectorFactory.getStandardStructObjectInspector(fieldNames,fieldOIs);
        }

        /**
         * @see 
org.apache.hadoop.hive.ql.udf.generic.GenericUDTF#process(java.lang.Object[])
         */
        @Override
        public void process(Object[] args) throws HiveException {
                kingdom_concept_id = (Integer) args[0];
                phylum_concept_id = (Integer) args[1];
        }
}