Re: [Owlim-discussion] how to use context in sparql?

[Barry Bishop]

Hi Yonghong,

A named graph is just that, a graph with a name. Sesame calls this name
a 'context'.

The way named graphs behave is to extend the triple data model to a
quad, i.e. each statement is subject-predicate-object-context, where
'context' can be null.

To add a statement with a context, here is an example:

Repository repository = ....;
RepositoryConnection conn = repository.getConnection();
ValueFactory vf = repository.getValueFactory();

URI subj = vf.createURI("http://example.org/owlim#Pilot";);
URI obj = vf.createURI("http://example.org/owlim#Human";);
URI context = vf.createURI("http://example.org/owlim#People";);
        
repositoryConnection.add(subj, RDF.TYPE, obj, context);
repositoryConnection.commit();
repositoryConnection.close();


I hope this helps,
barry

On 11/08/2010 18:09, yonghong ke wrote:
>  /It seems/ that a sesame context is different  from a named graph,
> isn't it?
> If i want to add a statement to a named graph,So how should do?
> 
> 
> 在 2010年8月4日 下午4:17，yonghong ke <kyh....@gmail.com
> <mailto:kyh....@gmail.com>>写道：
> 
>     Thank you very much,i'ill try what you said.
> 
>     在 2010年8月2日 下午5:02，Jacek Kopecky <j.kope...@open.ac.uk
>     <mailto:j.kope...@open.ac.uk>>写道：
> 
>         Hi Yonghong,
>         a quick example adapted from the link sent by Barry:
> 
>         SELECT *
>         FROM NAMED <http://example.org/example/example.rdf>
>         WHERE { your graph pattern }
> 
>         This should just use the triples in that particular context.
>         Hope it helps,
>         Jacek
> 
>         On 2 Aug 2010, at 09:46, Barry Bishop wrote:
> 
>         > Hi Yonghong,
>         >
>         > If you have not done this before, probably the best place to
>         start is to
>         > read here:
>         >
>         >    http://www.w3.org/TR/rdf-sparql-query/#namedGraphs
>         >
>         > You will need to use FROM or FROM NAMED or a combination of
>         the two. I
>         > won't explain further, as the above URL explains it better
>         than I could.
>         >
>         > Best of luck,
>         > barry
>         >
>         > --
>         > Barry Bishop
>         > OWLIM Product Manager
>         > Ontotext AD
>         > Tel: +43 650 2000 237
>         > email: barry.bis...@ontotext.com
>         <mailto:barry.bis...@ontotext.com>
>         > www.ontotext.com <http://www.ontotext.com/>
>         >
>         > On 02/08/2010 10:31, yonghong ke wrote:
>         >> Hi, all:
>         >>  I create a context like follow：
>         >>
>         >>      String location = "http://example.org/example/example.rdf";;
>         >>
>         >>      URI context = f.createURI(location);
>         >>
>         >>
>         >>      con.add(sub, predicate, obj, context);
>         >>
>         >>
>         >> i want to query  in the ‘context’ use sparql,  how should i do ?
>         >>
>         >> Thanks!
>         >>
>         >>
>         >>
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> 
>         --
>         The Open University is incorporated by Royal Charter (RC
>         000391), an exempt charity in England & Wales and a charity
>         registered in Scotland (SC 038302).
> 
> 
> 
> 
> 
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