About the

SPARQL Endpoint Web Service

The SPARQL Endpoint Web service is used to directly send SPARQL queries against UMBEL's data: (1) UMBEL subject concept and abstract concept RDF description, (2) UMBEL named entities RDF description and (3) UMBEL ontology classes and properties RDF description.

Users have to specify three items in order to query the UMBEL SPARQL endpoint:

1. One of these three graph URIs:
   • http://umbel.org/umbel/sc/. The graph of the subject concepts and abstract concepts descriptions
   • http://umbel.org/umbel/ne/. The graph of the named entities descriptions
   • http://umbel.org/umbel/. The graph of the classes and properties of the UMBEL ontology description
2. One of these UMBEL versions:
   • 071. UMBEL version 0.71
3. One of the MIME types for the resultset that is to be returned by the Web service.
   • application/sparql-results+xml. XML
   • application/sparql-results+json. JSON
   • text/html. HTML
   • application/rdf+n3. RDF+N3
   • application/rdf+xml. RDF+XML
   The document describing the data structure of the XML, JSON, RDF+N3 and RDF+XML serializations can be found here.
4. The actual SPARQL query to send against the SPARQL endpoint

What the endpoint returns is a resultset that contains the SPARQL query results returned by the datastore. The data structure of this resultset is based on the SPARQL Query Results XML Format and the Serializing SPARQL Query Results in JSON documents.

Note: The SPARQL Endpoint Web service is limited to returning a maximum of 100 results in the free online version.