- From: Simon Raboczi <raboczi@tucanatech.com>
- Date: Tue, 22 Jun 2004 10:25:53 -0400
- To: public-rdf-dawg@w3.org
On 18/06/2004, at 7:39, Kendall Clark wrote: > I can think of several use cases where what I care about isn't the > particular answers -- the actual string comprising someone's email > address -- but *that* some graph has "an email address". If we have anything resembling a SELECT clause that can be used to project away variables, you get this effect by projecting away ALL the variables. Once the projection operation finishes removing duplicates, you end up with either true or false depending whether there were any solutions or not. > Or, for example, I don't care about the values of foaf:knows > predicates, I > just want to know whether some FOAF resource contains more than 8 of > them. I think this is an entirely different kind of query. Rather than "Can this query be satisfied? I don't care about the particular variable bindings required to satisfy it.", it's "Calculate a particular variable binding ?x = (count > 8) whose value just happens to be a boolean". In this case you certainly will get an explicit literal value back, presumably datatyped using XSD. However, it's just a normal variable binding expression.
Received on Tuesday, 22 June 2004 10:26:31 UTC