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Re: Observations (named graphs, blank node closurs)

From: Steve Harris <S.W.Harris@ecs.soton.ac.uk>
Date: Sun, 20 Feb 2005 14:36:50 +0000
To: public-rdf-dawg@w3.org
Message-ID: <20050220143650.GI25631@login.ecs.soton.ac.uk>

On Sat, Feb 19, 2005 at 05:38:29PM +0100, Giovanni Tummarello wrote:
> Wouldnt it be fairly simple to add an automatic binding to the 
> "statement" as a 4th node for each triple and this to bind this to the 
> reification node/s?
> Example 
> SELECT ?name ?mbox ?date WHERE
>       (?g dc:publisher ?name ?triplecontext)
>       (?g dc:date ?date )
>       (?triplecontext  fuzzyont:certainty ?fuzzyval) and ?fuzzyval <0.8
> with ?triplecontext binding to the reification node of the said triple. 
> (if any) 

The named graphs stuff asside, this is what the GRAPH keyword does. eg.
your example above becomes:

SELECT ?name ?mbox ?date WHERE
      GRAPH ?triplecontext (?g dc:publisher ?name)
      (?g dc:date ?date )
      (?triplecontext  fuzzyont:certainty ?fuzzyval) and ?fuzzyval <0.8

My store is one of those that supports triple context via quads, currently
using exactly the syntaxic construct you give abover. However I prefer the
GRAPH keyword for readability, unambiguity and extensibility.

- Steve
Received on Sunday, 20 February 2005 14:43:40 UTC

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