Ed Summers wrote:
> I was just playing around w/ some SPARQL using dbpedia's endpoint and
> noticed that:
>
> SELECT *
> WHERE {
> ?person rdf:type <http://dbpedia.org/ontology/Person> .
> ?person rdfs:label ?personName .
> ?person <http://dbpedia.org/ontology/birthplace> ?place .
> ?place rdfs:label ?placeName .
> FILTER (lang(?personName) = "en")
> FILTER (lang(?placeName) = "en")
> }
>
> returns some hits but this returns 0:
>
> SELECT COUNT(*)
> WHERE {
> ?person rdf:type <http://dbpedia.org/ontology/Person> .
> ?person rdfs:label ?personName .
> ?person <http://dbpedia.org/ontology/birthplace> ?place .
> ?place rdfs:label ?placeName .
> FILTER (lang(?personName) = "en")
> FILTER (lang(?placeName) = "en")
> }
>
> Is there something wrong here either in my query or my expectation
> that the count query return > 0 ?
>
> //Ed
>
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>
Ed,
It's your query, you need optionals in there. Here is a quick mod that
focuses on the typical culprits (rdfs:label values):
SELECT COUNT(*)
WHERE {
?person rdf:type <http://dbpedia.org/ontology/Person> .
optional {?person rdfs:label ?personName} .
?person <http://dbpedia.org/ontology/birthplace> ?place .
optional {?place rdfs:label ?placeName} .
FILTER (lang(?personName) = "en")
FILTER (lang(?placeName) = "en")
}
--
Regards,
Kingsley Idehen Weblog: http://www.openlinksw.com/blog/~kidehen
President & CEO
OpenLink Software Web: http://www.openlinksw.com
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