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Re: RDF query in XML

From: Hugh Glaser <hg@ecs.soton.ac.uk>
Date: Sat, 8 Mar 2008 11:59:52 +0000
To: SW-forum list <semantic-web@w3.org>
Message-ID: <C3F83038.2340E%hg@ecs.soton.ac.uk>

So it seems you may simply be asking if there is a standard XML
serialisation for SPARQL.
So now I can ask another question: Is there an ontology for SPARQL?
Can I find a standard way to represent a SPARQL query in RDF, for example?
(If there is and I missed it, please ignore the rest.)

The question of what a SPARQL endpoint looks like is still not quite clear
( http://esw.w3.org/topic/SparqlEndpointDescription ), and how you hand over
the string which is the query is also problematic.
It seems to me that if we live in the Semantic Web, I should for example be
able to give a SPARQL service a URI that resolves to an RDF representation
of a query.

Anyone done this for RDF, or at least XML?

Cheers
Hugh


On 07/03/2008 13:40, "Indraneel R" <vascodagama1@gmail.com> wrote:

>
> 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 Saturday, 8 March 2008 12:00:25 UTC

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