diff --git a/rdf2graphml/src/main/java/uk/ac/rothamsted/kg/rdf2pg/graphml/export/support/GraphMLRelationExportHandler.java b/rdf2graphml/src/main/java/uk/ac/rothamsted/kg/rdf2pg/graphml/export/support/GraphMLRelationExportHandler.java
index ef320dd..cf1a914 100644
--- a/rdf2graphml/src/main/java/uk/ac/rothamsted/kg/rdf2pg/graphml/export/support/GraphMLRelationExportHandler.java
+++ b/rdf2graphml/src/main/java/uk/ac/rothamsted/kg/rdf2pg/graphml/export/support/GraphMLRelationExportHandler.java
@@ -62,6 +62,9 @@ public void accept ( Set<QuerySolution> relRecords )
 
 			// TODO: remove, debug
 			int relOndexId = Optional.ofNullable ( pgRelation.getProperties ().get ( "ondexId" ) )
+				.map ( pv -> ((Set<Object>) pv) )
+				.filter ( pvset -> !pvset.isEmpty () )
+				.map ( pvset -> pvset.iterator ().next () )
 	      .map ( String::valueOf )
 	      .map ( Integer::valueOf )
 	      .orElse ( -1 );
diff --git a/rdf2pg-core/src/main/java/uk/ac/rothamsted/kg/rdf2pg/pgmaker/support/rdf/RdfDataManager.java b/rdf2pg-core/src/main/java/uk/ac/rothamsted/kg/rdf2pg/pgmaker/support/rdf/RdfDataManager.java
index 1051e69..13e4d4c 100644
--- a/rdf2pg-core/src/main/java/uk/ac/rothamsted/kg/rdf2pg/pgmaker/support/rdf/RdfDataManager.java
+++ b/rdf2pg-core/src/main/java/uk/ac/rothamsted/kg/rdf2pg/pgmaker/support/rdf/RdfDataManager.java
@@ -124,13 +124,13 @@ public String getPGId ( RDFNode node, Function<String, String> idConverter )
 	 * It doesn't do anything if the query is null.
 	 * 
 	 */
-	protected void addPGProps ( PGEntity cyEnt, String propsSparql )
+	protected void addPGProps ( PGEntity pgEntity, String propsSparql )
 	{
 		ensureOpen ();		
 		Dataset dataSet = this.getDataSet ();
 		
 		QuerySolutionMap params = new QuerySolutionMap ();
-		params.add ( "iri", dataSet.getUnionModel().getResource ( cyEnt.getIri () ) );
+		params.add ( "iri", dataSet.getUnionModel().getResource ( pgEntity.getIri () ) );
 
 		// It may be omitted, if you don't have any property except the IRI.
 		if ( propsSparql == null ) return;
@@ -143,11 +143,11 @@ protected void addPGProps ( PGEntity cyEnt, String propsSparql )
 			{
 				String propName = this.getPGId ( row.get ( "name" ), propIdConverter );
 				if ( propName == null ) throw new IllegalArgumentException ( 
-					"Null property name for " + cyEnt.getIri () 
+					"Null property name for " + pgEntity.getIri () 
 				);
 				
 				String propValue = JENAUTILS.literal2Value ( row.getLiteral ( "value" ) ).get ();
-				cyEnt.addPropValue ( propName, propValue );
+				pgEntity.addPropValue ( propName, propValue );
 			},
 			params
 		);