My example is about wikidata. But, the goal is just about SPARQL and
federated queries. And Jena  seems to have a good support for fedarated
queries.

--
Jean-Claude Moissinac



Le ven. 20 déc. 2019 à 12:38, Marco Neumann <[email protected]> a
écrit :

> you are welcome Jean-Claude, BTW wikidata SPARQL query questions can be
> best discussed over at the wikidata mailing lists / sites
>
> On Fri, Dec 20, 2019 at 11:30 AM Jean-Claude Moissinac <
> [email protected]> wrote:
>
> > So, the shared variable ?wikidata must be in the inner select to be seen
> by
> > both triple store.
> > Many thank's
> > --
> > Jean-Claude Moissinac
> >
> >
> >
> > Le ven. 20 déc. 2019 à 11:57, Marco Neumann <[email protected]> a
> > écrit :
> >
> > > PREFIX wdt: <http://www.wikidata.org/prop/direct/>
> > > PREFIX wikibase: <http://wikiba.se/ontology#>
> > > PREFIX bd: <http://www.bigdata.com/rdf#>
> > > SELECT * where{
> > > bind(<http://www.wikidata.org/entity/Q640447> as ?wikidata).
> > > SERVICE <https://query.wikidata.org/bigdata/namespace/wdq/sparql> {
> > > select ?wikidata ?p ?propLabel ?o ?oLabel where {
> > > ?wikidata ?p ?o . ?prop wikibase:directClaim ?p .
> > > SERVICE wikibase:label {bd:serviceParam wikibase:language "en,fr" .}
> > > } } }
> > >
> > > On Fri, Dec 20, 2019 at 10:56 AM Marco Neumann <
> [email protected]>
> > > wrote:
> > >
> > > > ok I see, how about the following
> > > >
> > > >
> > > > On Fri, Dec 20, 2019 at 9:34 AM Jean-Claude Moissinac <
> > > > [email protected]> wrote:
> > > >
> > > >> In the second code, the bind must be inside the service <...> {...}
> > > >> --
> > > >> Jean-Claude Moissinac
> > > >>
> > > >>
> > > >>
> > > >> Le jeu. 19 déc. 2019 à 16:48, Jean-Claude Moissinac <
> > > >> [email protected]> a écrit :
> > > >>
> > > >> > Hello
> > > >> >
> > > >> > In an instance of Fuseki, I'm trying the following query
> > > >> >
> > > >> > PREFIX wdt: <http://www.wikidata.org/prop/direct/>
> > > >> >
> > > >> > prefix wikibase: <http://wikiba.se/ontology#>
> > > >> >
> > > >> > PREFIX bd: <http://www.bigdata.com/rdf#>
> > > >> >
> > > >> > SELECT * where
> > > >> >
> > > >> > {
> > > >> >
> > > >> > bind(<http://www.wikidata.org/entity/Q640447> as ?wikidata)
> > > >> >
> > > >> > service <https://query.wikidata.org/bigdata/namespace/wdq/sparql>
> {
> > > >> >
> > > >> > select ?p ?propLabel ?o ?oLabel where {
> > > >> >
> > > >> > ?wikidata ?p ?o . ?prop wikibase:directClaim ?p . SERVICE
> > > >> wikibase:label {
> > > >> > bd:serviceParam wikibase:language "en,fr" .
> > > >> >
> > > >> > } } } }
> > > >> >
> > > >> >
> > > >> > which fails with an error 500 (Error 500: HTTP 500 error making
> the
> > > >> query:
> > > >> > Internal Server Error)
> > > >> >
> > > >> > While the following one gives results:
> > > >> >
> > > >> > PREFIX wdt: <http://www.wikidata.org/prop/direct/>
> > > >> >
> > > >> > prefix wikibase: <http://wikiba.se/ontology#>
> > > >> >
> > > >> > PREFIX bd: <http://www.bigdata.com/rdf#>
> > > >> >
> > > >> > SELECT * where {
> > > >> >
> > > >> > bind(<http://www.wikidata.org/entity/Q640447> as ?wikidata)
> > > >> >
> > > >> > service <https://query.wikidata.org/bigdata/namespace/wdq/sparql>
> {
> > > >> >
> > > >> > select ?p ?propLabel ?o ?oLabel where {
> > > >> >
> > > >> > <http://www.wikidata.org/entity/Q640447> ?p ?o .
> > > >> >
> > > >> > ?prop wikibase:directClaim ?p . SERVICE wikibase:label {
> > > bd:serviceParam
> > > >> > wikibase:language "en,fr" .
> > > >> >
> > > >> > } } } }
> > > >> >
> > > >> >
> > > >> > In my real query, in place of the bind, I have some code which
> > selects
> > > >> > some wikidata entities. The goal is to get a wikidata description
> of
> > > >> these
> > > >> > entities
> > > >> >
> > > >> > Have you some ideas?
> > > >> >
> > > >> >
> > > >> > --
> > > >> > Jean-Claude Moissinac
> > > >> >
> > > >> >
> > > >>
> > > >
> > > >
> > > > --
> > > >
> > > >
> > > > ---
> > > > Marco Neumann
> > > > KONA
> > > >
> > > >
> > >
> > > --
> > >
> > >
> > > ---
> > > Marco Neumann
> > > KONA
> > >
> >
>
>
> --
>
>
> ---
> Marco Neumann
> KONA
>

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