[redland-dev] Problems traversing arcs with the same URI

[Simon Cross]

Hi Brian,

> I guess I am still hoping to find a simple way to do
> this.  What is it about the arcs returned from
> librdf_model_get_arcs_out() that prevents them from
> being uniquely applied in librdf_model_get_target()? 
> Is it just that arcs that have the same uri are
> treated as the same arc, even though they clearly are
> not?  What is it that makes nodes with the same uri
> unique, but gets ignored (I think) when I pass the
> node as the arc to librdf_model_get_target()?

The problem is that the various arc functions return URIs for the
predicates rather unique identifiers for the arcs.  This makes sense
because the only unique identifier for an arc is the complete triple,
which you would fetch using the various statement finding functions.

Unfortunately RDQL doesn't seem to support a SQL-like GROUP BY clause at
the moment - although it would be nice to have.  It'd also be nice to
have ORDER BY.

Schiavo
Simon