- From: Jonas Liljegren <jonas@rit.se>
- Date: 23 Nov 2000 17:52:16 +0100
- To: Graham Klyne <GK@Dial.pipex.com>
- Cc: "ML RDF-interest" <www-rdf-interest@w3c.org>
Graham Klyne <GK@Dial.pipex.com> writes:
> At 01:21 PM 11/23/00 +0100, Jonas Liljegren wrote:
> >Graham Klyne <GK@Dial.pipex.com> writes:
> >
> > > [S] --rdf:Type-----> [rdf:Statement]
> > > [S] --rdf:Subject--> [SomeResource]
> >
> >Heh! This could be used as an alternative to having dedicated
> >variable URIs in queries. The above would match all statements with
> >the specified subject.
>
> Something of the kind did occur to me...
>
>
> >But I still prefere having the varaiables...
>
> ... I can sympathize with that.
>
> But consider:
> [?S] --rdf:type-------> [rdf:Statement]
> [?S] --rdf:subject----> [SomeResource]
> [?S] --rdf:predicate--> [?A]
> [?S] --rdf:object-----> [?B]
> would match all resources that modelled statements about [SomeResource].
>
> What is the purpose of variables in such a query?
The variables is necessary if you want something two or more steps
away. As in:
[?S1] --rdf:type-------> [rdf:Statement]
[?S1] --rdf:subject----> [SomeResource]
[?S1] --rdf:predicate--> [?A]
[?S1] --rdf:object-----> [?B]
[?S2] --rdf:type-------> [rdf:Statement]
[?S2] --rdf:subject----> [?B]
[?S2] --rdf:predicate--> [type]
[?S2] --rdf:object-----> [?C]
This woulb be used to get all the types of the resource properties.
And since we are using whole statements, we can transfer and store
them in a more compact manner.
--
/ Jonas Liljegren
The Wraf project http://www.uxn.nu/wraf/
Sponsored by http://www.rit.se/
Received on Thursday, 23 November 2000 11:51:03 UTC