- From: Steve Harris <S.W.Harris@ecs.soton.ac.uk>
- Date: Mon, 23 Aug 2004 12:10:38 +0100
- To: rdf-interest <www-rdf-interest@w3.org>
On Mon, Aug 23, 2004 at 12:33:03 +0200, Alessandro Di Bella wrote: > Hi All, > I'm new to RDF and I'm trying to asses the feasibility of using OWL for a > product I'm developing. > I would like to know if being: > > A a metaclass > B a subclass of A > C a subclass of A > D a subclass of B > > How can i write an RDQL query saying that I wants to retrieve all the > instances of A? > And will the query understand my ontology and will it return instances of > B, C, D as well? That depends on the store your querying, not RDQL, also it only requires RDFS reasoning, which is more common than OWL reasoning. FWIW the query (against an RDFS complaint store) would just be: SELECT ?instance WHERE (?instance, <rdf:type>, A) - Steve
Received on Monday, 23 August 2004 11:10:41 UTC