Question: How many architects are there who have made something used by Oakland athletics?
SPARQL query:
PREFIX res: <http://dbpedia.org/resource/>
PREFIX prop: <http://dbpedia.org/property/>
PREFIX onto: <http://dbpedia.org/ontology/>
SELECT DISTINCT COUNT(?uri) WHERE { ?x onto:tenant <http://dbpedia.org/resource/Oakland_Athletics> . ?x prop:architect ?uri . }