- From: Dan Connolly <connolly@w3.org>
- Date: Thu, 12 May 2005 10:01:08 -0500
- To: Nicolas F Rouquette <nicolas.rouquette@jpl.nasa.gov>, public-rdf-dawg-comments@w3.org
> 1) Extracting the list of the ontologies defined in DOLCE. Hmm... I would expect to do that ala... SELECT ?ont WHERE { ?ONT rdf:type owl:Ontology }. Does DOLCE not declare its ontologies using rdf:type owl:Ontology? > I understand that SPARQL was specifically designed for context-free queries > that could be executed very efficiently and that extracting _:x in this example > requires tracking _:x and all of his "descendent" triples. > Be as it may, > it does not change the fact that this type of "projection" or "extraction" > from an OWL ontology is a reasonable thing to ask for. Hmm... yes, in fact, we have adopted a closely related use case... 2.17 Building Ontology Tools (Semantic Web) http://www.w3.org/TR/rdf-dawg-uc/#u2.17 note the "Motivates: Extensibility Mechanism" link below; i.e. we think this sort of query might involve things beyond SPARQL 1.0. Meanwhile, I think your query might be doable, if somewhat awkward, using OPTIONAL... http://www.w3.org/TR/2005/WD-rdf-sparql-query-20050419/#optionals > The problem boils down to a context-sensitive graph query > to retrieve things like: > > ns1:requisite > rdf:type owl:ObjectProperty ; > rdfs:domain [ rdf:type owl:Class ; > owl:unionOf (ns1:information-object ns1:course > ns1:role ns1:figure) > ] ; > rdfs:range ns1:parameter ; > rdfs:subPropertyOf :immediate-relation-i ; > owl:inverseOf ns1:requisite-for . > > In this case, there's a triple: > > ns1:requisite rdfs:domain _:x > > where _:x corresponds to this: > > [ rdf:type owl:Class ; > owl:unionOf (ns1:information-object ns1:course ns1:role ns1:figure) > ] You might try: CONSTRUCT { ?C rdfs:domain ?D. ?D rdf:type ?DT. ?D owl:unionOf ?DU } WHERE { ?C rdfs:domain ?D. OPTIONAL { ?D rdf:type ?DT } OPTIONAL { ?D olw:unionOf ?DU } }. and so on. The lists are particularly problematic. We don't have a good design for that, and we don't plan to in this version. See issue accessingCollections. http://www.w3.org/2001/sw/DataAccess/issues#accessingCollections -- Dan Connolly, W3C http://www.w3.org/People/Connolly/ D3C2 887B 0F92 6005 C541 0875 0F91 96DE 6E52 C29E see you at XTech in Amsterdam 24-27 May?
Received on Thursday, 12 May 2005 15:01:12 UTC