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Re: SPARQL triples with no variables

From: Axel Polleres <axel.polleres@deri.org>
Date: Mon, 30 Aug 2010 08:08:40 +0100
Cc: <public-sparql-dev@w3.org>
Message-Id: <6C207B3A-BE2C-4BB9-915F-477CD717BC5B@deri.org>
To: Graham Matthews <graham@orangedogconsulting.com>

On 28 Aug 2010, at 17:37, Graham Matthews wrote:

> Hi
> 
> I have a couple of questions about the semantics of some unusual SPARQL
> queries.
> 
> What is the semantics of the following SPARQL query?
> 
> select $x from graph_iri
> where
> {
>         $x a some_iri_1.
>         some_iri_2 some_iri_3 some_iri_4
> }
> 
> where all of the some_iri_i's are distinct, and the graph contains NO triples
> of the form
> 
>         some_iri_2 some_iri_3 some_iri_4
> 
> ?
> 
> Is the answer empty

yes. Basic graph patterns are always matched against the active graph in their entirety.

> or all $x's that satisfy the first triple?
> 
> Similarly what is the semantics of the following query?
> 
> select $x from graph_iri
> where
> {
>         $x a some_iri_1.
>         $y some_iri_3 some_iri_4
> }
> 
> where all of the some_iri_i's are distinct, and the graph contains NO triples
> that match the second
> pattern?

likewise.

> 
> thanks
> graham
> 

HTH,
Axel

> 
> 
> 
> 
Received on Monday, 30 August 2010 07:09:18 UTC

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