- From: Eric Prud'hommeaux <eric@w3.org>
- Date: Tue, 14 Feb 2006 10:45:30 -0500
- To: public-rdf-dawg@w3.org
- Message-ID: <20060214154530.GA28459@w3.org>
Re discussion of bNodes in different graphs discussion in today's meeting, would an example of a bNode that has a sort of fixed place in the universe help? I have been working on querying conventional relational data with SPARQL. A simple interpretation of a row in the Person table is a foaf:Person with some given name and other attributes. We view the primary key as an encoding artifact of the relational store and elect not to share that number with the outside world. -- Person -- primary key given email (unique key) 21857 Eric eric@w3.org 31572 Eric em@w3.org => mbox a owl:inverseFunctionalProperty . [ a foaf:Person ; given "Eric" ; mbox <mailto:eric@w3.org> ] . [ a foaf:Person ; given "Eric" ; mbox <mailto:em@w3.org> ] . I think this is a told blank node if my SPARQL impl *chooses* to constrain SELECT mbox ?o WHERE { _:pk21857 mbox ?o } to have a subject of the obvious primary key, yielding ?o <mailto:eric@w3.org> Unconstrained, this would yield ?o <mailto:eric@w3.org> <mailto:em@w3.org> This may help with Pat and Enrico's discussion, it may not... -- -eric office: +81.466.49.1170 W3C, Keio Research Institute at SFC, Shonan Fujisawa Campus, Keio University, 5322 Endo, Fujisawa, Kanagawa 252-8520 JAPAN +1.617.258.5741 NE43-344, MIT, Cambridge, MA 02144 USA cell: +81.90.6533.3882 (eric@w3.org) Feel free to forward this message to any list for any purpose other than email address distribution.
Received on Tuesday, 14 February 2006 15:45:38 UTC