- From: Richard Cyganiak <richard@cyganiak.de>
- Date: Sun, 26 Sep 2010 17:00:48 +0100
- To: Christophe Guéret <cgueret@few.vu.nl>
- Cc: Linked Data community <public-lod@w3.org>
Sounds like it might be an instance of this problem:
http://www.semanticoverflow.com/questions/947/dbpedia-sparql-endpoint-xsddate-comparison-weirdness
If not, then perhaps asking this on the DBpedia mailing list might get
better responses.
https://lists.sourceforge.net/lists/listinfo/dbpedia-discussion
Best,
Richard
On 26 Sep 2010, at 16:03, Christophe Guéret wrote:
> Hello,
>
> There seems to be an issue with the SPARQL end point of DBPedia, http://dbpedia.org/sparql
> .
>
> When I run this first query:
>
> SELECT ?result WHERE {<http://dbpedia.org/resource/WVNS-DT2
> <http://dbpedia.org/resource/WVNS-DT2>>
> <http://dbpedia.org/ontology/formationDate
> <http://dbpedia.org/ontology/formationDate>> ?result. }
>
> I get the following result telling me that ?result is a date:
>
> <sparql xmlns="http://www.w3.org/2005/sparql-results#"
> xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
> xsi:schemaLocation="http://www.w3.org/2001/sw/DataAccess/rf1/result2.xsd
> ">
> <head>
> <variable name="result"/>
> </head>
> <results distinct="false" ordered="true">
> <result>
> <binding name="result"><literal
> datatype="http://www.w3.org/2001/XMLSchema#date">2006-09-13</
> literal></binding>
> </result>
> </results>
> </sparql>
>
>
> But when I want to find a resource which matches that specific date,
> no result are returned:
>
> SELECT ?result WHERE { ?result
> <http://dbpedia.org/ontology/formationDate> "2006-09-13"^^<http://www.w3.org/2001/XMLSchema#date
> >. }
>
> gives
>
> <sparql xmlns="http://www.w3.org/2005/sparql-results#"
> xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
> xsi:schemaLocation="http://www.w3.org/2001/sw/DataAccess/rf1/result2.xsd
> ">
> <head>
> <variable name="result"/>
> </head>
> <results distinct="false" ordered="true">
> </results>
> </sparql>
>
>
> Could this be a bug of some sort? I also tried to run the same
> couple of queries on http://lod.openlinksw.com/sparql and everything
> works fine there.
>
>
> Cheers,
> Christophe
>
>
> --
> Dr. Christophe Guéret (cgueret@few.vu.nl)
> http://cgueret.net
> Postdoc working on SOKS (http://www.few.vu.nl/soks)
> Knowledge Representation& Reasoning Group
> Computational Intelligence Group
> Department of Computer Science, AI
> VU University Amsterdam
>
> <cgueret.vcf>
Received on Sunday, 26 September 2010 16:01:24 UTC