Hi,
I installed Virtuoso on Windows. Now I want to work with Sparql queries
(connected to Openlink Virtuoso on cmd).
I have an rdf file called 'example.rdf'. I want to run this Sparql query:
SPARQL PREFIX ore:<http://www.openarchives.org/ore/terms/> PREFIX dc:<http:
purl.org/dc/elements/1.1/> SELECT distinct ?resource ?title FROM
<D:/example.rdf/> WHERE {?resource ore:proxyIn ?proxy . ?resource dc:title
?title .};
The result: resource title LONG VARCHAR LONG VARCHAR
So I get empty results instead of resource and title values. How can I get
these two columns?
I'm sure that my Sparql query is correct because I get the title and
resource values when I am running the same Sparql above on Java or on R.
I notice that I get empty result on every running Sparql on Virtuoso. For
example, also at this query I get empty result:
SPARQL SELECT ?p ?s WHERE { { SELECT DISTINCT ?p ?s FROM <http://dbpedia.org>
WHERE { ?s ?p <http://dbpedia.org/resource/Germany> } ORDER BY ASC(?p)
} } OFFSET 50000 LIMIT 1000;
The result of this query: p s LONG VARCHAR LONG VARCHAR
How can I solve this problem? Do I need to install or to do something else
for running sparql queries? E.g. jena libraries (I have virt_jena.jar file
in the folder jena and virt_jena2.jar in the folder jena2). Thanks!
Best regards,
Esra
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