SPARQL endpoint for querying multiple datasets

[royassis]

Hey there

I want to build a cross dataset SPRAQL query.
I am trying to use the FROM clause but it seems that the SPARQL endpoint is set to only one dataset.

Does Fuseki server have a endpoint where I can submit cross dataset queries ?

[flange-ipb]

Hi @royassis,

the FROM keyword may be used for selection of a named graph inside the dataset you are querying.
A cross dataset query should be doable via a SPARQL federated query. In particular, querying a dataset on the same Fuseki instance can be achieved by using http://127.0.0.1:3030/datasetname/ as the target endpoint.

Example:

SELECT *
WHERE {
  SERVICE <http://127.0.0.1:3030/datasetname> {
    ?s ?p ?o
  }
}
LIMIT 10

[royassis]

Hey @flange-ipb thanks for the response. I used your suggestion.

Regarding the FROM and FROM NAMED keywords.
In the RDF spec they mention FROM and FROM named in this context:

A SPARQL query may specify the dataset to be used for matching by using the FROM clause and the FROM NAMED clause to describe the RDF dataset

I'm still a bit confused.

[afs]

"describe the dataset" here means enumerate the graphs to have in the dataset.

FROM and FROM identify the graphs to go into a dataset that is then queried.