SPARQL Examples – Federation

Posted on Aug 31, 2017 (last modified May 7, 2021)

Federate data from 2 endpoints

Find the birth dates of all of the actors in Star Trek: The Motion Picture.
Try this on ARQ.

PREFIX movie: <http://data.linkedmdb.org/resource/movie/> PREFIX dbpedia: <http://dbpedia.org/ontology/> PREFIX foaf: <http://xmlns.com/foaf/0.1/> SELECT ?actor_name ?birth_date FROM <http://www.w3.org/People/Berners-Lee/card> # placeholder graph WHERE { SERVICE <http://data.linkedmdb.org/sparql> { <http://data.linkedmdb.org/resource/film/675> movie:actor ?actor . ?actor movie:actor_name ?actor_name } SERVICE <http://dbpedia.org/sparql> { ?actor2 a dbpedia:Actor ; foaf:name ?actor_name_en ; dbpedia:birthDate ?birth_date . FILTER(STR(?actor_name_en) = ?actor_name) } }

The SERVICE keyword is used to send part of a query against a remote SPARQL endpoint.