Correction: "... and the final result on *fuseki-admin* comes out empty."
On Tue, Nov 26, 2024 at 9:56 AM Martynas Jusevičius <marty...@atomgraph.com> wrote: > > Hi, > > I have two Fuseki 4.6.1 instances in a Docker network (fuseki-admin > and fuseki-end-user) that federate SPARQL queries between each other. > > When I execute this query on fuseki-admin: > > PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> > PREFIX acl: <http://www.w3.org/ns/auth/acl#> > PREFIX sioc: <http://rdfs.org/sioc/ns#> > > SELECT * > FROM <urn:x-arq:UnionGraph> > WHERE > { VALUES ( ?this ?Container ) { > ( <https://localhost:4443/whateverest/> <https://localhost:4443/> ) > } > SERVICE <http://fuseki-end-user:3030/ds/> > { GRAPH ?Container > { ?Container a ?Type } > } > } > > then I can see the ?Container binding was injected into the query > string executed on fuseki-end-user: > > Query = SELECT * WHERE { GRAPH <https://localhost:4443/> { > <https://localhost:4443/> a ?Type } } > > However when I add FILTER NOT EXISTS to the federated part > > PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> > PREFIX acl: <http://www.w3.org/ns/auth/acl#> > PREFIX sioc: <http://rdfs.org/sioc/ns#> > > SELECT * > FROM <urn:x-arq:UnionGraph> > WHERE > { VALUES (?this ?Container) { (<https://localhost:4443/whateverest/> > <https://localhost:4443/>) } > SERVICE <http://fuseki-end-user:3030/ds/> > { GRAPH ?Container > { > ?Container a ?Type > } > FILTER NOT EXISTS { GRAPH ?this > { ?this > sioc:has_parent|sioc:has_container ?Container } > } > } > } > > I see a single request in fuseki-end-user but none of the variables > are bound to anything: > > Query = Query = SELECT * WHERE { GRAPH ?Container { > ?Container a ?Type } FILTER NOT EXISTS { GRAPH ?this > { ?this > <http://rdfs.org/sioc/ns#has_parent>|<http://rdfs.org/sioc/ns#has_container> > ?Container } > > This looks plain wrong because without bindings it eliminates too many > (positive) results, and the final result on fuseki-end-user comes out > empty. > > Is this a bug or am I misunderstanding something about VALUES and/or SERVICE? > > Martynas
