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Re: Querying Named Graph using SPARQL

From: David Booth <david@dbooth.org>
Date: Tue, 13 Aug 2013 14:21:17 -0400
Message-ID: <520A791D.2070504@dbooth.org>
To: Axel Polleres <axel@polleres.net>
CC: Quentin Reul <Quentin.H.Reul@gmail.com>, semantic-web@w3.org, public-rdf-wg@w3.org, public-sparql-dev@w3.org
Hi Axel,

That doesn't work in Sesame 2.7.1 at least, apparently because ?G is not 
bound, even though there is one solution.  The SPARQL 1.1 spec says:
http://www.w3.org/TR/sparql11-query/#emptyGroupPattern
[[
The group pattern:
   { }
matches any graph (including the empty graph) with one solution that 
does not bind any variables.
]]

Is this a bug in the spec?

David

On 08/13/2013 11:48 AM, Axel Polleres wrote:
> Hi Quentin,
>
> how about just
>
>   SELECT ?G WHERE { GRAPH ?G {} }
>
> (no need to dump all triples, if the only concern is which ?G exist)
>
> BTW, public-sparql-dev@w3.org may be the list you wanted to use.
>
> best,
> Axel
>
Received on Tuesday, 13 August 2013 18:21:45 UTC

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