W3C home > Mailing lists > Public > www-rdf-interest@w3.org > September 2004

RE: querying reacheability using RDQL

From: Seaborne, Andy <andy.seaborne@hp.com>
Date: Wed, 8 Sep 2004 11:55:10 +0100
Message-ID: <8D5B24B83C6A2E4B9E7EE5FA82627DC96969@sdcexcea01.emea.cpqcorp.net>
To: "Alessandro Di Bella" <aldib@fuurou.org>
Cc: <www-rdf-interest@w3.org>

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/

	Andy

________________________________

From: 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
Received on Wednesday, 8 September 2004 10:55:44 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Monday, 7 December 2009 10:52:09 GMT