Dear All, Thanks for your support. Yes, I can now able to work with Aggregate Functions.
- Regards On Mon, May 12, 2014 at 9:59 PM, Hugh Williams <[email protected]>wrote: > Andy, > > On 12 May 2014, at 13:19, Andy Seaborne <[email protected]> wrote: > > > On 12/05/14 12:54, Hugh Williams wrote: > >> Hi Rob, > >> > >> What is not SPARQL 1.1 about the query being run ie > >> > >> select distinct ?T1 ?T2 count(*) from <http://dbpedia.org> > >> where > >> { > >> ?s1 <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> ?T1. > >> ?s2 <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> ?T2. > >> ?s1 <http://dbpedia.org/property/spouse> ?s2. > >> ?s2 <http://dbpedia.org/property/birthPlace> ?obj. > >> FILTER(REGEX(?T1, "http://dbpedia.org/ontology/";)). > >> FILTER(REGEX(?T2, "http://dbpedia.org/ontology/";)). > >> } > >> group by ?T1 ?T2 > >> > >> The only potential problem I see is the "count(*)" which maybe have to > be changed to be "(count(*) as ?count)" as in the specs if this is not > deemed to be SPARQL 1.1 ie > > > > It is not legal SPARQL 1.1. > > > >> select distinct ?T1 ?T2 (count(*) as ?count) from <http://dbpedia.org> > >> where > >> { > >> ?s1 <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> ?T1. > >> ?s2 <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> ?T2. > >> ?s1 <http://dbpedia.org/property/spouse> ?s2. > >> ?s2 <http://dbpedia.org/property/birthPlace> ?obj. > >> FILTER(REGEX(?T1, "http://dbpedia.org/ontology/";)). > >> FILTER(REGEX(?T2, "http://dbpedia.org/ontology/";)). > >> } > >> group by ?T1 ?T2 > >> > >> Which seems to work against other endpoints ... > >> > >> Would be nice if the Jena SPARQL validator at > http://www.sparql.org/validator.html worked to check ? > >> > > > > What "would be nice"? > > > > It correctly shows it to be an error unless you enable extensions. > > [Hugh] The validator was giving a "service unavailable" error, earlier but > is working now ... > > > > >> I note in the code Jena snippet below the call > "QueryFactory.create(query, Syntax.syntaxSPARQL_11);" , which seems to be > forcing the invocation of the Jena Parser, but if the > "Syntax.syntaxSPARQL_11" param is removed then it should bypass the Jena > parser and pass Query on to Virtuoso as is , as detailed at: > >> > >> > http://virtuoso.openlinksw.com/dataspace/doc/dav/wiki/Main/VirtJenaProvider#Bypass%20Jena/ARQ%20parser > > > > is 'query' the same in both code snippets? > > [Hugh] Should be the same ... > > Regards > Hugh > > > > > Andy > > > >> > >> Best Regards > >> Hugh Williams > >> Professional Services > >> OpenLink Software, Inc. // http://www.openlinksw.com/ > >> Weblog -- http://www.openlinksw.com/blogs/ > >> LinkedIn -- http://www.linkedin.com/company/openlink-software/ > >> Twitter -- http://twitter.com/OpenLink > >> Google+ -- http://plus.google.com/100570109519069333827/ > >> Facebook -- http://www.facebook.com/OpenLinkSoftware > >> Universal Data Access, Integration, and Management Technology Providers > >> > >> On 12 May 2014, at 09:17, Rob Vesse <[email protected]> wrote: > >> > >>> Yes, though the Virtuoso specific syntax shown there is not legal > SPARQL > >>> > >>> See Aggregates (http://www.w3.org/TR/sparql11-query/#aggregates) in > the > >>> SPARQL 1.1 specification which Jena fully supports > >>> > >>> Rob > >>> > >>> On 12/05/2014 05:49, "Md Mizanur Rahoman" <[email protected]> wrote: > >>> > >>>> Dear Experts, > >>>> > >>>> My question is: > >>>> > >>>> Is there any Jena implementation that can execute Aggregate function > like > >>>> count, sum etc? Iterative counting of all elements could an option, > >>>> however, I want to know about direct implement of below method. > >>>> > >>>> such as, the below method > >>>> > >>>> ------------------------------ > >>>> > ------------------------------------------------------------------------ > >>>> public void queryExecutor(VirtGraph dataset) { > >>>> > >>>> String query = > >>>> "select distinct ?T1 ?T2 count(*) "+ > >>>> "from <http://dbpedia.org> "+ > >>>> "where "+ > >>>> "{ "+ > >>>> "?s1 <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> ?T1. "+ > >>>> "?s2 <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> ?T2. "+ > >>>> "?s1 <http://dbpedia.org/property/spouse> ?s2. "+ > >>>> "?s2 <http://dbpedia.org/property/birthPlace> ?obj. "+ > >>>> "FILTER(REGEX(?T1, \"http://dbpedia.org/ontology/\";)). "+ > >>>> "FILTER(REGEX(?T2, \"http://dbpedia.org/ontology/\";)). "+ > >>>> "}"+ > >>>> "group by ?T1 ?T2 "; > >>>> > >>>> > >>>> System.out.println(query); > >>>> > >>>> Query sparql1 = QueryFactory.create(query, > >>>> Syntax.syntaxSPARQL_11); > >>>> try { > >>>> VirtuosoQueryExecution vqe1 = > >>>> VirtuosoQueryExecutionFactory.create(sparql1, dataset); > >>>> ResultSet results1 = vqe1.execSelect(); > >>>> > >>>> } > >>>> catch (Exception e) { > >>>> System.out.println("Error in query execution: " + > >>>> e.toString()); > >>>> e.printStackTrace(); > >>>> } > >>>> > >>>> } > >>>> > -------------------------------------------------------------------------- > >>>> --------------------------------- > >>>> > >>>> > >>>> - > >>>> Regards > >>>> Mizan > >>>> NII, Japan > >>>> > >>>> > >>>> > >>>> ---------- Forwarded message ---------- > >>>> From: Md Mizanur Rahoman <[email protected]> > >>>> Date: Wed, May 7, 2014 at 7:35 PM > >>>> Subject: Group By Query in Jena Java > >>>> To: [email protected] > >>>> > >>>> > >>>> Dear Expert, > >>>> > >>>> I want to execute a group by query in Jena. I am using Jena V2.6.4. > But it > >>>> is giving exception > >>>> > -------------------------------------------------------------------------- > >>>> --------------------------- > >>>> > >>>> Exception in thread "main" com.hp.hpl.jena.query.QueryParseException: > >>>> Encountered " "count" "count "" at line 1, column 26. > >>>> > >>>> > -------------------------------------------------------------------------- > >>>> ---------------------------- > >>>> And here is my method, > >>>> > >>>> > -------------------------------------------------------------------------- > >>>> ---------------------------- > >>>> public void queryExecutor(VirtGraph dataset) { > >>>> > >>>> String query = > >>>> "select distinct ?T1 ?T2 count(*) "+ > >>>> "from <http://dbpedia.org> "+ > >>>> "where "+ > >>>> "{ "+ > >>>> "?s1 <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> ?T1. "+ > >>>> "?s2 <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> ?T2. "+ > >>>> "?s1 <http://dbpedia.org/property/spouse> ?s2. "+ > >>>> "?s2 <http://dbpedia.org/property/birthPlace> ?obj. "+ > >>>> "FILTER(REGEX(?T1, \"http://dbpedia.org/ontology/\";)). "+ > >>>> "FILTER(REGEX(?T2, \"http://dbpedia.org/ontology/\";)). "+ > >>>> "}"+ > >>>> "group by ?T1 ?T2 "; > >>>> > >>>> > >>>> System.out.println(query); > >>>> > >>>> Query sparql1 = QueryFactory.create(query, > >>>> Syntax.syntaxSPARQL_11); > >>>> try { > >>>> VirtuosoQueryExecution vqe1 = > >>>> VirtuosoQueryExecutionFactory.create(sparql1, dataset); > >>>> ResultSet results1 = vqe1.execSelect(); > >>>> > >>>> } > >>>> catch (Exception e) { > >>>> System.out.println("Error in query execution: " + > >>>> e.toString()); > >>>> e.printStackTrace(); > >>>> } > >>>> > >>>> } > >>>> > -------------------------------------------------------------------------- > >>>> --------------------------------- > >>>> > >>>> My question is: > >>>> > >>>> * Is there any Jena version that can execute Aggregate function like > >>>> count, > >>>> sum etc? > >>>> > >>>> - > >>>> Regards > >>>> Mizanur > >>>> NII, Japan > >>> > >>> > >>> > >>> > >> > > > > -- *Md Mizanur Rahoman* PhD Candidate The Graduate University for Advanced Studies National Institute of Informatics 2-1-2 Hitotsubashi, Chiyoda-ku, Tokyo 101-8430, Japan. Cell # +81-80-4802-5848 Email: [email protected] Web: https://sites.google.com/site/mdmizanurrahoman/ Linked In: http://www.linkedin.com/pub/md-mizanur-rahoman/20/7b8/45a
