Hi I have just discovered that a query with count have a behaviour that is different from the same query without count. Now, I might be missing something, but here is what happens. My understanding is that COUNT only counts the statements that would otherwise be returned using the same SPARQL query without COUNT.
Query: PREFIX onto: <http://dbpedia.org/ontology/> PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> SELECT DISTINCT ?uri WHERE { ?cave rdf:type onto:Cave . ?cave onto:location ?uri . OPTIONAL {?uri rdfs:label ?string. FILTER (lang(?string) = 'en') } } HAVING (count(?cave) > 2) returns 18 results now the same query but with count PREFIX onto: <http://dbpedia.org/ontology/> PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> SELECT count(DISTINCT ?uri) WHERE { ?cave rdf:type onto:Cave . ?cave onto:location ?uri . OPTIONAL {?uri rdfs:label ?string. FILTER (lang(?string) = 'en') } } HAVING (count(?cave) > 2) returns 156 it seems that it ignores the part with HAVING(count(?cave)>2) as PREFIX onto: <http://dbpedia.org/ontology/> PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> SELECT count(DISTINCT ?uri) WHERE { ?cave rdf:type onto:Cave . ?cave onto:location ?uri . OPTIONAL {?uri rdfs:label ?string. FILTER (lang(?string) = 'en') } } returns 156 as well -- Best, Danica Damljanovic -- Research Associate GATE team http://gate.ac.uk Natural Language Processing Group University of Sheffield http://www.dcs.shef.ac.uk/~danica ------------------------------------------------------------------------------ EMC VNX: the world's simplest storage, starting under $10K The only unified storage solution that offers unified management Up to 160% more powerful than alternatives and 25% more efficient. Guaranteed. http://p.sf.net/sfu/emc-vnx-dev2dev _______________________________________________ Dbpedia-discussion mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/dbpedia-discussion
