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Re: SPARQL results in RDF

From: Hugh Glaser <hg@ecs.soton.ac.uk>
Date: Sat, 21 Sep 2013 18:38:18 +0000
To: William Waites <ww@styx.org>
CC: "public-lod@w3.org community" <public-lod@w3.org>
Message-ID: <AA10A4BB-EB9D-4E8B-9727-32801A6BFD11@soton.ac.uk>
Many thanks, William, and for confirming so quickly.
(And especially thanks for not telling me that CONSTRUCT does what I want!)
I had suddenly got excited that RDF might actually be useable to represent something I wanted to represent, just like we tell other people :-)
So it is all non-standard, as I suspected.
Ah well, I'll go back to trying to work with XML stuff, instead of using my usual RDF tools :-(
Very best
Hugh

On 21 Sep 2013, at 19:14, William Waites <ww@styx.org>
 wrote:

> Hi Hugh,
> 
> You can get results in RDF if you use CONSTRUCT -- which is basically
> a special case of SELECT that returns 3-tuples and uses set semantics
> (does not allow duplicates), but I imagine that you are aware of this.
> 
> Returning RDF for SELECT where the result set consists in n-tuples
> where n != 3 is difficult because there is no direct way to represent
> it. 
> 
> Also problematic is that there *is* a concept of order in SPARQL query
> results while there is not with RDF.
> 
> Also the use of bag semantics allowing duplicates which also does not
> really work with RDF.
> 
> These, again, could be kludged with reification, but that is not very
> elegant. 
> 
> So most SELECT results are not directly representable in RDF.
> 
> Cheers,
> -w
> 
Received on Saturday, 21 September 2013 18:38:58 UTC

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