OK, so it's possible to invoke SQL from SPARQL. Great.
But how to get the result back to SPARQL?
For example, I want to fetch the list of registered namespaces (SELECT *
from RDF_PREFIX).
How can I get this list back to a SPARQL endpoint? Thanks beforehand.
Pierre
2008/2/6, Tim Haynes <tim.hay...@openlinksw.co.uk>:
>
> Pierre De Wilde wrote:
> > Hi,
> > It seems possible to call SQL from SPARQL as referenced in doc 'Calling
> SQL
> > from SPARQL' (ยง15.2.5).
> > Have you some examples? Is it possible to call statements
> > like backup_online('backup_#', 10000); from a SPARQL endpoint?
> >
>
> Well, I can give you a different example off the top of my head:
>
> create procedure db.dba.removegraphsmatching (in pattern varchar) {
> declare r1, r2 integer;
> r1:=(select count(*) from db.dba.rdf_quad where id_to_iri (G) like
> pattern);
> delete from db.dba.rdf_quad where id_to_iri (G) like pattern;
> r2:=(select count(*) from db.dba.rdf_quad where id_to_iri (G) like
> pattern);
> return r1-r2;
> };
>
> sparql select ?g ?s ?p ?o WHERE {
> GRAPH ?g { ?s ?p ?o . }
> filter sql:removegraphsmatching ( 'pattern%' ) };
>
> The important thing to note is that the stored procedure in question must
> be in the db.dba schema/space.
>
> Shouldn't be hard to make the sp do something less destructive :)
>
> HTH,
>
> ~Tim
> --
> Tim Haynes
> OpenLink Software
> <http://www.openlinksw.com/>
>
