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Re: Querying different SPARQL endpoints

From: (wrong string) čius <martynas@graphity.org>
Date: Wed, 19 Dec 2012 20:56:30 +0200
Message-ID: <CAE35VmxmZxNRA1nGxPaYYgHK_CNSP1_m_wHwWN-Oqq4wxkAGbg@mail.gmail.com>
To: Vishal Sinha <vishal.sinha777@yahoo.com>
Cc: "public-lod@w3.org" <public-lod@w3.org>
Hey Vishal,

knowledge of structure can be useful but is not necessary. Probably
the most common pitfall is not to check if named graphs were used.
Your can try this query that handles both cases (default and named graphs):

PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX owl: <http://www.w3.org/2002/07/owl#>
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>

SELECT DISTINCT *
WHERE
{
    { ?s ?p ?o }
    UNION
    {
GRAPH ?g
{ ?s ?p ?o }
    }
}

Martynas
graphity.org

On Wed, Dec 19, 2012 at 8:28 PM, Vishal Sinha <vishal.sinha777@yahoo.com> wrote:
> There are many public SPARQL endpoints available.
> For example the cultural linked data:
> http://cultura.linkeddata.es/sparql
>
> How can I know what type of information is available in this dataset.
> Based on what assumption I can query it?
> Do I need to know any structure beforehand?
>
> Viashal
>
Received on Wednesday, 19 December 2012 18:56:57 UTC

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