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Re: [OK?]

From: Seaborne, Andy <andy.seaborne@hp.com>
Date: Wed, 11 Jan 2006 15:35:31 +0000
Message-ID: <43C525C3.2060504@hp.com>
To: Faisal.Alkhateeb@inrialpes.fr
CC: public-rdf-dawg-comments@w3.org



Faisal.Alkhateeb@inrialpes.fr wrote:
> 
> Hello,
> 
>   Happy new year for all and I wish you a lot of success.

Thank you and Happy New Year

> 
> I have just some questions: 
> 
> 1. the fisrt one regarding the collections, if we have the following example:
> 
> (1 ?x 3) :p "w" ;
>          foaf:mbox ?mbox .

> 
> Since there are no explicit interpretations, I want to know the equivalent 
> triples.

(1 ?x 3) is just syntax for the thing written out as triple patterns and the 
blank node at the head of (1 ?x 3) is the common subject for the foaf:mbox ?mbox .

I get:

   { _:b0  rdf:first  1 ;
           rdf:rest   _:b1 .
     _:b1  rdf:first  ?x ;
           rdf:rest   _:b2 .
     _:b2  rdf:first  3 ;
           rdf:rest   rdf:nil .
     _:b0  :p         "w" ;
           foaf:mbox  ?mbox .
   }

and with no ";":

   { _:b0 rdf:first 1 .
     _:b0 rdf:rest _:b1 .
     _:b1 rdf:first ?x .
     _:b1 rdf:rest _:b2 .
     _:b2 rdf:first 3 .
     _:b2 rdf:rest rdf:nil .
     _:b0 :p "w" .
     _:b0 foaf:mbox ?mbox .
   }

(I used ARQ's command arq.qparse to get those)

http://www.w3.org/2001/sw/DataAccess/rq23/#collections

> 
> 
> 2. The second one is when there are no FROM and FROM NAMED in te query, what 
> is/are the graph database(s) (i.e. RDF dataset).

The protocol may have default-graph-uri and named-graph-uri.  If these are not 
present, it is whatever the SPARQL service provides - the client does not 
specify in the request.  For example, a service may provide access to a book 
catalogue.  There is one dataset and the service does not answer queries 
involving FROM/FROM NAMED or default-graph-uri/named-graph-uri.

The order of deciding which dataset is
    protocol request - query string - service

I hope that answers your questions

	Andy

> 
> Faisal Alkhateeb
Received on Wednesday, 11 January 2006 15:35:49 GMT

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