I haven't used sparql-mode, but endpoint
isn't part of the SPARQL syntax. The service
keyword is used to indicate federated query. It's described more fully in SPARQL 1.1 Federated Query, and there are examples. I think that your query would be something along the lines of:
select distinct ?concept where {
service <http://dbpedia.org/sparql> {
[] a ?concept
}
}
limit 5
I'm not familiar with all the details, so I'm not sure about whether the remote endpoint gets the information about the limit 5
or not, so it might be helpful to handle it with a subquery within the service
:
select ?concept where {
service <http://dbpedia.org/sparql> {
select distinct ?concept where {
[] a ?concept
}
limit 5
}
}
As I said, I don't have sparql-mode, but I can run that query with Jena's command line sparql
tool, and I get the kind of results that one would expect. (You might want to increase that limit
, though; the first five results I tend to get are things like:
-----------------------------------------------------------------------
| concept |
=======================================================================
| <http://www.w3.org/1999/02/22-rdf-syntax-ns#Property> |
| <http://www.openlinksw.com/schemas/virtrdf#QuadMapFormat> |
| <http://www.openlinksw.com/schemas/virtrdf#QuadStorage> |
| <http://www.openlinksw.com/schemas/virtrdf#array-of-QuadMap> |
| <http://www.openlinksw.com/schemas/virtrdf#QuadMap> |
| <http://www.openlinksw.com/schemas/virtrdf#array-of-QuadMapFormat> |
which are not the useful DBpedia classes you're probably expecting.)