I am new to Fuseki and Stardog, and I am trying to use a sparql SERVICE query to access some of the information in a Jena Fuseki (2.4.0) server with the Stardog (4.2) interface. The issue I am having is that every query I try ends up with an "Internal Server Error". Here is an example:
select ?f ?g
WHERE {
SERVICE <http://localhost:3030/resultados/query> {
?f a ?g
}
}
Looking at the http messages sent, I found that Fuseki answers with a 400 code error with the following code:
Error 400: Parse error:
SELECT ?f ?g
WHERE {
?f rdf:type ?g
}
Line 3, column 6: Unresolved prefixed name: rdf:type
Which seems to indicate that it doesn't support the rdf prefix. However, if I include it in the query, the error message changes to "Multiple prefix declarations for prefix 'rdf'"
Is there some configuration in Fuseki or Stardog that I might be missing to allow these queries? Both are installed with the default settings.
Thanks