DBpedia SPARQL 和谓词连接

Question

I've got a problem with the DBpedia SPARQL endpoint because the properties of the properties like the label of rdf:type are not stocked in the endpoint. So when I run this query:

SELECT * 
WHERE{
  <http://dbpedia.org/ontology/Place> ?predicat ?object .
  OPTIONAL{?predicat rdfs:label ?label}
}

I've got nothing for?label.

If someone got any idea to solve this problem it would be very helpful.

Answer 1

You can't get the real labels from DBpedia because the SPARQL endpoint doesn't have them. But you can take the local name of the property URI. So, for rdfs:subClassOf you'd get "subClassOf". That's better than nothing. This can be done using Virtuoso's (non-standard) bif:regexp_replace function.

SELECT DISTINCT (bif:regexp_replace(STR(?p), "^.*[/#]", "") AS ?label) WHERE {
   <http://dbpedia.org/ontology/Place> ?p ?o .
}

Answer 2

I don't think there's a SPARQL solution. Dbpedia doesn't have the data you want, and I couldn't easily find a SPARQL endpoint for that RDF at W3C. And I don't think the Virtuoso dbpedia endpoint supports federation yet, even if we did find a SPARQL endpoint for W3C.

Happy to be proven wrong on any of those points.