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Re: DBpedia SPARQL Endpoint and Transitive Queries

From: Antoine Isaac <aisaac@few.vu.nl>
Date: Thu, 08 Oct 2009 17:42:23 +0200
Message-ID: <4ACE085F.1060902@few.vu.nl>
To: Alexandre Passant <alexandre.passant@deri.org>
CC: Kingsley Idehen <kidehen@openlinksw.com>, "dbpedia-discussion@lists.sourceforge.net" <dbpedia-discussion@lists.sourceforge.net>, "public-lod@w3.org" <public-lod@w3.org>
Alexandre Passant a écrit :
> Hi,
> 
> On 8 Oct 2009, at 16:09, Kingsley Idehen wrote:
> 
>> All,
>>
>> The intersection of Leigh Dodds SPARQL extensions survey [1], imminent 
>> official release of Virtuoso 6.0 (DBpedia basic and Live already use 
>> this, ditto LOD Cache, and B3S public endpoints), and an old post by 
>> Bernard Vatant re. skos:broader, has lead to this simple, but powerful 
>> example of  Virtuoso's Transitive Option extension for SPARQL :
>>
>> #Transitive Option Off
>>
>> PREFIX p: <http://dbpedia.org/property/>
>> PREFIX dbpedia: <http://dbpedia.org/resource/>
>> PREFIX category: <http://dbpedia.org/resource/Category:>
>> PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
>> PREFIX skos: <http://www.w3.org/2004/02/skos/core#>
>> PREFIX geo: <http://www.georss.org/georss/>
>>
>> SELECT DISTINCT ?m ?n ?p ?d
>> WHERE {
>>  ?m rdfs:label ?n.
>>  ?m skos:subject ?c.
>>  ?c skos:broader category:Churches_in_Paris.
>>  ?m p:abstract ?d.
>>  ?m geo:point ?p
>> FILTER ( lang(?n) = "fr" )
>> FILTER ( lang(?d) = "fr" )
>> }
>>
>> #Transitive Option On
>>
>> PREFIX p: <http://dbpedia.org/property/>
>> PREFIX dbpedia: <http://dbpedia.org/resource/>
>> PREFIX category: <http://dbpedia.org/resource/Category:>
>> PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
>> PREFIX skos: <http://www.w3.org/2004/02/skos/core#>
>> PREFIX geo: <http://www.georss.org/georss/>
>>
>> SELECT DISTINCT ?m ?n ?p ?d
>> WHERE {
>>  ?m rdfs:label ?n.
>>  ?m skos:subject ?c.
>>  ?c skos:broader category:Churches_in_Paris OPTION (TRANSITIVE).
>>  ?m p:abstract ?d.
>>  ?m geo:point ?p
>> FILTER ( lang(?n) = "fr" )
>> FILTER ( lang(?d) = "fr" )
>> }
>>
>>
> 
> As skos:broader is not transitive [1] but its superproperty 
> skos:broaderTransitive is, shouldn't the second query be
> 
>  ?c skos:broaderTransitive category:Churches_in_Paris OPTION (TRANSITIVE).
> 
> Best,
> 
> Alex.
> 
> [1] http://www.w3.org/TR/2009/REC-skos-reference-20090818/#L2413


+1. Also, skos:subject is not in the recommendation...

Best,

Antoine
Received on Thursday, 8 October 2009 15:42:52 UTC

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