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RE: querying reacheability using RDQL

From: Chris Catton <chris.catton@zoology.oxford.ac.uk>
Date: Fri, 10 Sep 2004 10:39:16 +0100
To: <www-rdf-interest@w3.org>
Message-ID: <007401c4971a$0a15c800$0301a8c0@chios>
Hii,

A variation on this which might prove useful is using a transitive
property and then using different reasoners to differentiate direct and
indirect arcs - so using a transitive reasoner will give you t2,t3, and
t4 and a non-transitive reasoner will just give you t2 and t3. 

Chris Catton

BioImage Database Development Manager

Department of Zoology

University of Oxford

OX1 3PS

 

Tel: +44 (0) 1865 281993

email: chris.catton@zoology.oxford.ac.uk

web site:  <outbind://98/www.bioimage.org> www.bioimage.org

 

 

> -----Original Message-----

> From: www-rdf-interest-request@w3.org 

> [ <mailto:www-rdf-interest-request@w3.org>
mailto:www-rdf-interest-request@w3.org] On Behalf Of Seaborne, Andy

> Sent: 08 September 2004 11:55

> To: Alessandro Di Bella

> Cc: www-rdf-interest@w3.org

> Subject: RE: querying reacheability using RDQL

> 

> 

> 

> Query expressions in RDQL are of fixed length so, no, you can't write 

> an arbitrary reachability query.

> 

> One way it can happen is if the source provides inference and there is


> some super property which is transitive. Then it is just a matter of 

> asking (?x :p ?y).

> 

> An example would be rdfs:subClassOf.

> 

> Do you have a concrete use case for this requirement? The RDF Data 

> Access Working group is working on a query language and it is 

> gathering

> requirements:

> 

 <http://www.w3.org/TR/rdf-dawg-uc/> http://www.w3.org/TR/rdf-dawg-uc/

Andy

________________________________

From: www-rdf-interest-request@w3.org [
<mailto:www-rdf-interest-request@w3.org>
mailto:www-rdf-interest-request@w3.org] On Behalf Of Alessandro Di Bella

Sent: 7 September 2004 16:18

To: www-rdf-interest@w3.org

Subject: querying reacheability using RDQL

 

Hi,

Is it possible to query the reachability of a resource from another? For
example, given the triples:

t1, cxn1, t2

t1, cxn2, t3

t2, cxn3, t4

t5, cnx4, t6

 

can i execute a query that says: 

select all individuals that can be reached from t1 

and that returns

t2 (direct arc)

t3 (direct arc)

t4 (indirect arc through t2)

?

Thanks

Alessandro

 

 

 

 

 

 

Chris Catton

BioImage Database Development Manager

Department of Zoology

University of Oxford

OX1 3PS

 

Tel: +44 (0) 1865 281993

email: chris.catton@zoology.oxford.ac.uk

web site: www.bioimage.org

 

 
Received on Friday, 10 September 2004 09:39:20 GMT

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