Re: [Rdfapi-php-interest] Nested SPARQL Graph Patterns

[<pl...@do...>]

Christian (or whoever may be able to answer :),

Unfortunately (unless you've spotted something I've not?) I don't see =20
any way that you can disambiguate this case. How can we know from the =20
Query object if the query was
  {
       { ?s :p1 ?o }
     OPTIONAL
       { ?s :p2 ?o2 . }
       { ?s :p3 ?o3 . }
  }

or

  {
       { ?s :p1 ?o }
     OPTIONAL
       { { ?s :p2 ?o2 . }
         { ?s :p3 ?o3 . }
       }
  }

...as the Query object contains nothing linking those BGPs (?s :p2 ?o2 =20
and ?s :p3 ?o3) as the right hand side of the OPTIONAL? They are =20
simply graph patterns in the Array, the same as ?s :p1 ?o; the SPARQL =20
engine will simply join them onto the result, not left-join them. Am I =20
missing something?

Cheers,
Peter

Quoting Christian Weiske <cw...@cw...>:

> Peter,
>
>> triple pattern. However, RAP parses this into a Query opbject
>> equivalent to:
>>
>> {
>>      { ?s :p1 ?o }
>>    OPTIONAL
>>      { }
>>      { ?s :p2 ?o2 . }
>>      { ?s :p3 ?o3 . }
>> }
>
> This is a behavior of SparqlParser that is weird, but cannot be taken
> away simply due to the internal working.
> In my SparqlEngineDb, I check if the pattern is empty and skip it in
> that case.
>
>
> --
> Regards/Mit freundlichen Gr=FC=DFen
> Christian Weiske
>
> -------------------------------------------------------------------------
> This SF.net email is sponsored by: Microsoft
> Defy all challenges. Microsoft(R) Visual Studio 2005.
> http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/
> _______________________________________________
> Rdfapi-php-interest mailing list
> Rdf...@li...
> https://lists.sourceforge.net/lists/listinfo/rdfapi-php-interest
>