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RE: RDF query in XML

From: Tom Heath <Tom.Heath@talis.com>
Date: Fri, 7 Mar 2008 17:45:34 -0000
Message-ID: <DD5E887552496241BC701548837A282F0692E152@nemo.talis.local>
To: "Indraneel R" <vascodagama1@gmail.com>, "Danny Ayers" <danny.ayers@gmail.com>
Cc: "SW-forum list" <semantic-web@w3.org>

Hi neel,

If I've understood your goals correctly, the approach we used for our
"SparqPlug" RDFizing service may be relevant or interesting.

The approach we took is to convert the XHTML DOM into an RDF graph which
can then be queried with SPARQL to extract the required/desired data,
which (if we use CONSTRUCT queries) is then available as a nice neat bit
of RDF/XML according to whichever vocabs/ontologies we choose, ready for
use in some other application. OTTOMH I don't see any reason why this
approach wouldn't work for you in general.

There are full technical details of the approach in the paper at [1]
from the upcoming Linked Data on the Web workshop at WWW2008, and the
live SparqPlug service is at [2], although you probably want to read the
paper first ;)

HTH,

Tom.

[1]
http://events.linkeddata.org/ldow2008/papers/05-coetzee-heath-sparqplug.
pdf
[2] http://sparqplug.rdfize.com/


> -----Original Message-----
> From: semantic-web-request@w3.org 
> [mailto:semantic-web-request@w3.org] On Behalf Of Indraneel R
> Sent: 07 March 2008 13:41
> To: Danny Ayers
> Cc: SW-forum list
> Subject: Re: RDF query in XML
> 
> 
> Thanks for the reply.
> 
>    Ok i will elaborate a bit. Actually I am doing a project 
> which involves RDF/XML. One side of the application uses XML 
> and more specifically voicexml and this also generates pages 
> in XML . So it would be easier and faster if somehow i could 
> use these pages itself as an input to the query language 
> which would read from these pages, query the rdf and returns 
> the results.
>    Also if i can specify the query in XML then i can generate 
> the xml pages  tailored to the specifications of the query 
> language , to query the RDF/XML files.
>    The problem with SPARQL is the queries have to be 
> specified in its own SQL type syntax, which is off course not 
> in xml , so here i will have to parse those XML pages(from 
> the 1st part of the app)  and extract information from it and 
> then convert them into SPARQL queries.
> 
> Regards,
> neel.
> 
> On Fri, Mar 7, 2008 at 3:23 PM, Danny Ayers 
> <danny.ayers@gmail.com> wrote:
> 
> 
> 	[forwarding to semantic-web@w3.org]
> 	
> 
> 	On 06/03/2008, neelr <vascodagama1@gmail.com> wrote:
> 	>
> 	>  Hi everyone,
> 	>         I am quite new to this RDF. I am currently 
> working on a project
> 	>  which involves RDF. I wanted to know if there is any 
> software or query
> 	>  language which can query RDF/XML files in XML.
> 	>      What I mean here is the syntactic constructs of 
> the query language
> 	>  should be in XML,i.e, I should be able to write the 
> queries in XML.
> 	>       Hope to hear from you guys soon.
> 	
> 	
> 	It would be helpful to know what kind of queries you 
> have in mind.
> 	
> 	Because you can say the same thing in many different 
> ways in RDF/XML,
> 	in general it doesn't really lend itself to XML style 
> querying (XQuery
> 	etc). But most serializers have some kind of 
> constrained syntax, so if
> 	you know it's all coming out of the same API then 
> you're in with a
> 	better chance. Another alternative would be to 
> translate to one of the
> 	more regular XML syntaxes, like Trix [1].
> 	
> 	SPARQL [2] is generally the best bet for querying RDF, 
> and it's done
> 	against the model/data rather than any specific 
> serialisation (and you
> 	get XML out). There were a handful of alternative query 
> languages
> 	floating around prior to SPARQL, could well be an XML-based on
> 	somewhere - try the ESW Wiki [3].
> 	
> 	There are also a few XPath-like languages around that 
> would allow
> 	queries against the graph (rather than the tree of 
> XML), see [4].
> 	
> 	While I can't remember seeing SPARQL done in XML, I 
> would guess a
> 	syntax mapping should be relatively straightforward. 
> The top-level
> 	grammar should fit pretty nicely into an XML hierarchy, 
> the pattern
> 	part should be expressable using (presumably 
> namespaced) RDF/XML, with
> 	the inclusion of a new construct for variables. It's 
> all Unicode. An
> 	XSLT transformation to regular SPARQL could be hooked 
> onto the front
> 	end of an existing query engine for your implementation.
> 	
> 	But then again, without knowing what you have in mind, 
> it's hard to
> 	see what would be gained from using an XML-based 
> language rather than
> 	SPARQL.
> 	
> 	Cheers,
> 	Danny.
> 	
> 	
> 	[1] http://www.hpl.hp.com/techreports/2004/HPL-2004-56.html
> 	[2] http://www.w3.org/TR/rdf-sparql-query/
> 	[3] http://esw.w3.org/topic/RDF_Query
> 	[4] http://esw.w3.org/topic/RdfPath
> 	
> 	--
> 	http://dannyayers.com
> 	~
> 	http://blogs.talis.com/nodalities/this_weeks_semantic_web/
> 	
> 
> 
> 
Received on Friday, 7 March 2008 17:45:52 UTC

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