Aggregates and Project Expressions in SPARQL 1.1 require that you use brackets around them and that they be aliased using the AS keyword e.g.
SELECT (COUNT(?inst) AS ?instances) FROM <http://dbpedia.org> WHERE { ?inst a <http://dbpedia.org/ontology/Activity> } If you change your query to the above it should work fine unless you are using a really outdated version of ARQ. Regards, Rob > -----Original Message----- > From: 朱曼 [mailto:[email protected]] > Sent: 08 August 2011 15:15 > To: [email protected] > Subject: is count function supported? > > Dear list, > > The following code causes "com.hp.hpl.jena.query.QueryParseException". > Is > count function supported? > > import com.hp.hpl.jena.query.*; > String queDBPedia = "select count(?inst)\n" > + "from <http://dbpedia.org>\n" > + "where {?inst a < > http://dbpedia.org/ontology/Activity>}"; > Query query = QueryFactory.create(queDBPedia); > > Or do I need to count the total number after I get all the instances? > Thanks for your time! > > Best regards > > June
