- From: Alberto Reggiori <areggiori@webweaving.org>
- Date: Mon, 17 Feb 2003 16:35:46 +0100
- To: Libby Miller <Libby.Miller@bristol.ac.uk>
- Cc: www-rdf-rules@w3.org, Alberto Reggiori <areggiori@webweaving.org>
- Message-Id: <7BA35F22-428D-11D7-8864-000393A63C18@webweaving.org>
On Friday, February 14, 2003, at 05:09 PM, Libby Miller wrote: > http://esw.w3.org/t/view/ESW/RDFQueryTestCases > > I've started a wiki page about RDF query testcases requirements: > > http://esw.w3.org/t/view/ESW/RDFQueryTestcasesRequirements I can not access the above pages at the moment but I look into those later on... > > I've jotted down some things that I think are required, based on a RDF > query testcases manifest format I've been using for query testcases > > http://swordfish.rdfweb.org/rdfquery/tests/query-results-manifest.rdf it looks good - I like a lot the use of N-Triples/N3 as input syntax with bNodes for the query but I wondering how we could express in N-Triples/N3 additional constraints such the ones with AND clause in Squish/RDQL e.g. SELECT ?x, ?y WHERE ...... AND (?x < 20 && ?y eq 'blaa' || ?y =~ /laa/ ) or one of your SquishQL examples [1] (such additional constraints clauses are not in the original QL98 paper). Anyway, even if I feel that developers and coders are still liking much more the SQL-ness of RDF query languages, the use of N-Triples/N3 as a good "neutral" syntax to express simple sub-graph matching and transformations in queries it could be a win win point. For the result set [2] in your manifest file you used some vocabulary which reminds to me about XHTML TABLEs - I just had a try to markup your sample result set as XHTML like RDF document (see attachment)...nothing more than an interesting experiment :-) > The main issue for me is how to express the query itself. > My inclination is to try and express queries as graphs with parts > missing, that is, to interpret an RDF graph as a query, as Jos de Roo > suggested [5]. +1 but we need to decide what to do with meaty constraints/features such as AND clauses in SquishQL/RDQL or similar in other query languages. > I think this would give us one big win, which is that we could ignore > the syntactic differences between several very similar query languages > for RDF (although this will by no means encompass all RDF query > languages). Plus of course, we get the query parser for free. Perhaps we could split up the test cases more: - sub-graph matching/selection and transformation tests (N3/N-Triples) - query language specific constraints and rules tests (native query syntax) > I would suggest sometime in the week of 24th February, maybe Thursday > 27th at 17:00 GMT. It sounds good to me as well - I should be able to make it even if I will be traveling from the 22-28. Some hotel room with a telephone line should be enough to make it :-) Alberto [1] http://swordfish.rdfweb.org/rdfquery/tests/queries/q5b.sq [2] http://swordfish.rdfweb.org/rdfquery/tests/rdf/rs/q3.rdf
Attachments
- application/octet-stream attachment: xhtml.rdf
Received on Monday, 17 February 2003 10:33:44 UTC