Hello Ole, The property for abstract has been changed since DBPedia Version 3.5: Instead of dbpedia2:abstract you have to query for dbo:abstract now. Then your query works.
Because such changes can happen from time to time you can check your queried properties in case of an empty result by yourself: Probably the easiest way is to browse to a resource that you expect in your result, e.g. Berlin http://dbpedia.org/resource/Berlin Benjamin ________________________________________ Von: Ole Begemann [[email protected]] Gesendet: Dienstag, 4. Mai 2010 11:58 An: [email protected] Betreff: [Dbpedia-discussion] Problem with SPARQL query returning 0 results Hello, I am new to this list. I am also a DBpedia and SPARQL noob so please excuse what might be a dumb question. A few months ago I played around with DBpedia and tried to construct a query that would return Wikipedia articles around a certain geo location. This is the query that I came up with (to search for German articles with geodata in and around Berlin, between 52-53 deg north and 13-14 deg east): PREFIX geo: <http://www.w3.org/2003/01/geo/wgs84_pos#> PREFIX foaf: <http://xmlns.com/foaf/0.1/> PREFIX dbpedia: <http://dbpedia.org/> PREFIX dbpedia2: <http://dbpedia.org/property/> PREFIX dbo: <http://dbpedia.org/ontology/> SELECT ?subject ?label ?lat ?long ?url ?thumbnailurl ?abstract WHERE { ?subject geo:lat ?lat . ?subject geo:long ?long . ?subject rdfs:label ?label . ?subject foaf:page ?url . ?subject dbo:thumbnail ?thumbnailurl . ?subject dbpedia2:abstract ?abstract . FILTER(xsd:float(?lat) >= 52.0 && xsd:float(?lat) <= 53.0 && xsd:float(?long) >= 13.0 && xsd:float(?long) <= 14.0 && lang(?label) = "de" && lang(?abstract) = "de" ) . } Using http://dbpedia.org/sparql as an endpoint, this query worked fine when I tried it a few months ago. But when I tried it again recently (over the last month or so), it only returned an empty result set: { head = { link = ( ); vars = ( subject, label, lat, long, url, thumbnailurl, abstract ); }; results = { bindings = ( ); distinct = 0; ordered = 1; }; } Can you spot what I am doing wrong? Has anything changed on the DBpedia side? I appreciate your help. Ole ------------------------------------------------------------------------------ _______________________________________________ Dbpedia-discussion mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/dbpedia-discussion ------------------------------------------------------------------------------ _______________________________________________ Dbpedia-discussion mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/dbpedia-discussion
