Re: [Tracker] Basic Reasoning

[Martyn Russell <martyn lanedo com>]

On 11/06/13 06:58, אנטולי קרסנר wrote:
> Thanks, now I understand it better.
>
> I'm not sure I need a reasoner, I just need to be able to do queries
> which don't rely on explicit relations and properties.
>
> To be honest, I didn't read much about SPARQL so maybe it can do
> everything I need without reasoning... I asked just to be sure I can
> implement the user queries I need.
>
> I guess I'll see when I get there and start using actual queries.

Ivan is right, you would need to perform more than one query here. For 
example:

  $ tracker-sparql -q "select ?s where { ?s rdfs:subClassOf nfo:Document }"

  Results:
    http://www.semanticdesktop.org/ontologies/2007/03/22/nfo#TextDocument
    http://www.semanticdesktop.org/ontologies/2007/03/22/nfo#Presentation
    http://www.semanticdesktop.org/ontologies/2007/03/22/nfo#Spreadsheet
    http://www.semanticdesktop.org/ontologies/2007/03/22/nfo#MindMap
    http://www.semanticdesktop.org/ontologies/2007/03/22/nfo#Note
    http://www.semanticdesktop.org/ontologies/2007/03/22/nfo#HelpDocument

I believe you would have to do it again for nfo:TextDocument and so on 
to find out the classes there.

Sadly, I don't think we have a way to find the parent for a class right 
now, it's one directional at the moment.

--
Regards,
Martyn

Founder and CEO of Lanedo GmbH.