> What am I doing wrong? Nothing. The SPARQL parser at the far end is rather touchy.
Works using wget or curl: http://sparql.data.southampton.ac.uk/?query=SELECT+%3Fo+%7B+%3Fs+%3Fprop+%3Fo+%7D+LIMIT+1 Does not work: http://sparql.data.southampton.ac.uk/?query=SELECT+%3Fo+%7B+%3Fs+%3Fprop+%3Fo+%7D+LIMIT++1 The difference is an extra space "LIMIT 1" > Any help to make it right? Try QueryExecution qexec = new QueryEngineHTTP(sparqlEndPoint, qString3) ; which by passes local query parsing/string conversion. Andy On 01/03/16 15:54, Carlo.Allocca wrote:
Dear All, I am using Jena to query a SPARQL endpoint but I got "==== No variables ====" as result. But, when I run the same query over the SPARQL endpoint, I get the expected results. Below, I reported the details of the query, sparql endpoint and jena code. I tried to check other endpoints, but I got the same experience. What am I doing wrong? Any help to make it right? Many Thanks, Best Regards, Carlo === Query Southampton SPARQL endpoint 1) SPARQL EndPoint: String sparqlEndPoint = "http://sparql.data.southampton.ac.uk/";; 2) SPARQL Query: String qString3 = "prefix rdfs:<http://www.w3.org/2000/01/rdf-schema#> " + "prefix rdf:<http://www.w3.org/1999/02/22-rdf-syntax-ns#> " + " SELECT DISTINCT ?o where " + "{ " + " ?s ?prop ?o . " + " FILTER (isLiteral(?o)) " + "} LIMIT 1000"; 3) Jena code: QueryExecution qexec = QueryExecutionFactory.sparqlService(sparqlEndPoint, qString3, ""); qexec.setTimeout(10 * 60 * 1000); //10 min ResultSet results = qexec.execSelect(); ResultSetFormatter.out(out, results); 4) Jena Result: ==== No variables ==== ---- | | ==== 5) SPARQL endpoint Results: http://www.w3.org/2000/01/rdf-schema#label http://www.w3.org/2004/02/skos/core#prefLabel http://www.w3.org/2000/01/rdf-schema#label http://www.w3.org/2004/02/skos/core#prefLabel http://www.w3.org/2000/01/rdf-schema#comment http://www.w3.org/2000/01/rdf-schema#label http://www.w3.org/2004/02/skos/core#prefLabel http://www.w3.org/2000/01/rdf-schema#comment http://www.w3.org/2000/01/rdf-schema#label http://www.w3.org/2004/02/skos/core#prefLabel
