I was fearing that... So if I want that aggregation with that data, I need to code it myself until they support it...
Thanks for your help. 2011/9/29 Andy Seaborne <[email protected]> > On 29/09/11 14:10, Luis Daniel Ibáñez González wrote: > >> Hi, >> >> I've been playing with Jena (v. 2.6.4 with ARQ 2.8.7) using dbpedia's >> endpoint, and the following query: >> >> SELECT ?title (GROUP_CONCAT(?platforms) AS ?plat) >> WHERE >> { >> ?game<http://purl.org/dc/**terms/subject<http://purl.org/dc/terms/subject>> >> < >> http://dbpedia.org/resource/**Category:First-person_shooters<http://dbpedia.org/resource/Category:First-person_shooters> >> **> . >> ?game foaf:name ?title . >> ?game dbpprop:platforms ?platforms >> } >> GROUP BY ?title >> >> parsed from String with the proper constructor yields: >> >> Exception in thread "main" HttpException: HttpException: 400 Bad Request: >> HttpException: 400 Bad Request >> at >> com.hp.hpl.jena.sparql.engine.**http.HttpQuery.execCommon(** >> HttpQuery.java:337) >> at >> com.hp.hpl.jena.sparql.engine.**http.HttpQuery.execGet(** >> HttpQuery.java:189) >> at >> com.hp.hpl.jena.sparql.engine.**http.HttpQuery.exec(HttpQuery.**java:144) >> at >> com.hp.hpl.jena.sparql.engine.**http.QueryEngineHTTP.** >> execSelect(QueryEngineHTTP.**java:133) >> at jenatest.Main.main(Main.java:**58) >> >> either using default syntax or ARQ syntax. >> >> If i use "Count" it works with both syntax. >> >> Nothing special with the factories, I used: >> >> Query query = QueryFactory.create(**queryString,Syntax.syntaxARQ); >> QueryExecution qexec = QueryExecutionFactory.**sparqlService(" >> http://dbpedia.org/sparql";, query); >> >> before the execution. >> >> Am I doing something wrong? >> > > No -- what it means is that DBPedia does not support GROUP_CONCAT. > > 400 (Bad Request) is almost certainly "syntax error". Try their UI. > > QueryEngineHTTP.execSelect sends the whole query (after local checking) to > the far end. > > Andy > > > >> Thanks in advance for your help. >> >> > -- Ing. Luis Daniel Ibáñez G.
