kinda SOLVED - Was: Re: Basic SPARQL question : foaf <-> modulus query matching with blank nodes

Henry Story <henry.story@bblfish.net> writes:

> On 18 Jul 2012, at 11:18, Olivier Berger wrote:
>
>> ...
>> <http://www-public.it-sudparis.eu/~berger_o/foaf.rdf#me>
>>    a :Person ;
>>    cert:key <http://www-public.it-sudparis.eu/~berger_o/foaf.rdf#mecert> ;
>>    :familyName "Berger" ;
>>    :firstName "Olivier" ;
>> 
>> <http://www-public.it-sudparis.eu/~berger_o/foaf.rdf#mecert>
>>    a cert:RSAPublicKey ;
>>    cert:exponent "65537"^^<xsd:int> ;
>
> that should be 
>
>      cert:exponent 66637
> or
>      cert:exponent "66637"^^xsd:int
>
> ( but I imagine that's a typo on your part... )
>

No : it's what rapper -o turtle gave me, I think...

>
>> 
>> The difference is that in the first one, I explicitely gave a URI to my
>> cert.
>> 
>> Aren't blank nodes supposed to serve in graph construction in SPARQL
>> queries ?
>
> They should. 
>
>> Have I hit a virtuoso limitation ?
>
> I doubt it. There must be another explanation to that.
>

I found it : it's the way blank nodes get inserted in Virtuoso in
Erfurt's code that was wrong.

So Erfurt 1.1's the culprit
(https://github.com/AKSW/Erfurt/issues/20#issuecomment-7062664 for reference)

>
>> 
>> I think I'll try with the MySQL backend option of Erfurt to try and see
>> if (it works and) I hit a similar behaviour.
>> 

Actually, provided a few fixes, it was able to perform the SPARQL query
allright using MySQL backend instead of Virtuoso ;)

That's the benefit of searching for solving that issue : I've found a
motivation to test Erfurt both over Virtuoso and MySQL ;)

Sorry for the bothering, and thanks for the useful feedback.

Best regards,
-- 
Olivier BERGER 
http://www-public.it-sudparis.eu/~berger_o/ - OpenPGP-Id: 2048R/5819D7E8
Ingenieur Recherche - Dept INF
Institut Mines-Telecom, Telecom SudParis, Evry (France)

Received on Wednesday, 18 July 2012 10:47:33 UTC