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" <mi...@nii.ac.jp> 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 <mi...@nii.ac.jp>
>Date: Wed, May 7, 2014 at 7:35 PM
>Subject: Group By Query in Jena Java
>To: users@jena.apache.org
>
>
>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
