Question: Which city has the oldest running metro?
SPARQL query:
PREFIX onto: <http://dbpedia.org/ontology/> PREFIX res: <http://dbpedia.org/resource/> PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> select ?loc where { ?uri onto:type res:Rapid_transit . ?uri onto:openingYear ?date . ?uri onto:location ?loc . ?loc rdf:type onto:City . } ORDER BY ASC(?date) LIMIT 1