Correcting myself in case someone wants to do it with the dbpedia webinterface: the syntax is: http://docs.openlinksw.com/virtuoso/fn_GROUP_CONCAT.html
Now, back to Jena, suppose that I want that aggregated data from dbpedia to do something else that needs programming, can I query this endpoint with its syntax? 2011/9/29 Luis Daniel Ibáñez González <[email protected]> > 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. > > > -- Ing. Luis Daniel Ibáñez G.
