- From: Yoshio FUKUSHIGE <fuku@w3.org>
- Date: Tue, 14 Dec 2004 20:41:27 +0900
- To: "Steve Harris" <S.W.Harris@ecs.soton.ac.uk>, <public-rdf-dawg@w3.org>
>> PREFIX foaf: <http://xmlns.com/foaf/0.1/> >> SELECT ?name, ?nick >> WHERE (?x foaf:name ?name) >> [(?x foaf:nick ?nick) >> (?x foaf:givenname ?nick)] >> [(?x foaf:nick ?nick) >> (?x foaf:surname ?nick)] > > This would be quite confusing as you could get one solution with two > different results for ?nick, using the current execution model. I think. Oh... Thank you, Steve, for pointing it out. Yes, you are right. The optional conditions can be met at the same time, which slipped from my mind... Hmm, what can I do with my uneasiness... It comes from the fact that whenever one adds a new clause to a query under construction, one has to check if variables in the new clause confilict with other variables in existing clauses. Do you think it is a painful but unevitable and necessary task for users? Or at least a realistic solution? Only if we had some mechanism for explicitly denoting the scope of the variables! Introducing such mechanism, however, would be very laborious... Hmm Yoshio
Received on Tuesday, 14 December 2004 11:41:31 UTC