>Have you considered using GRAPH in the query?  That is the better way to 
>access a specific graph. GRAPH accesses the dataset's graphs, while FROM 
>describes the dataset.

Yes I had, but here I have no choice considering my goal. I build a SPARQL 
proxy based on the work of Costabello and Gandon ( INRIA sophia antipolis : 
http://wimmics.inria.fr/projects/shi3ld/ )


This proxy rewrite on the fly SPARQL queries and and FROM <graph> clauses to 
restrict the range of the query. Realising that FROM interpretation can change 
depending the endpoint implementation is very annoying. It doesn't appear 
explicitly in the standard, but I have to live with it.

I was just in integration trouble as the way Fuseki was start totally impacted 
the core functionalities of the security layer.

Arthur VAÏSSE-LESTEVEN


________________________________
 De : Andy Seaborne <[email protected]>
À : [email protected] 
Envoyé le : Lundi 30 septembre 2013 15h22
Objet : Re: Trubble with config.ttl that impact  queries' semantics
 

On 30/09/13 07:44, Arthur Vaïsse-Lesteven wrote:
> Hi again,
>
>
>
>> What's in config.ttl?
> I made my tests with the default file "config.ttl" that defined 2 datasets, 
> "ds" and "books". As "books" doesn't support SPARQL update I made my tests on 
> "ds".
> Testing with the default "config-tdb.ttl" allow the 2 queries to work on the 
> "TDB Service (RW)" dataset.
>
> Just to check if I correctly understood,
> If my query contains "FROM <http://example.com#MyGraph>"
>
> In case of TDB the service will check if any local graph match this URI.
>
> Others will send an HTTP get to http://example.com#MyGraph, and execute the 
> query on the dataset built on the base of this result.
>
> That is correct ?

Yes.

> Can we swap a non-TDB service to a TDB behaviour concerning the "from <graph 
> uri>" ?

Not in the current codebase.  The behaviour of FROM to GET a URL 
remotely is a valid usecase.  There could be another implementation of 
DatasetGraph that provided dynamic datasets.  (I have unfinished code in 
my personal github to do this.)

> If yes, I supposed we have to override some class to change this behaviour.

Have you considered using GRAPH in the query?  That is the better way to 
access a specific graph. GRAPH accesses the dataset's graphs, while FROM 
describes the dataset.

PREFIX uso: <http://weblab.ow2.org/SWAG_users_ontology#>
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>

SELECT ?p ?o ?n
WHERE {
   GRAPH <http://swag_data.com/users_graph> {
     ?user uso:name "[email protected]"^^xsd:String.
     ?user uso:password "liferay_portal"^^xsd:String.
     ?user ?p ?o.
     OPTIONAL { ?o uso:name ?n }
   }
}



>
> Arthur VAÏSSE-LESTEVEN

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