Last modified 8 years ago
Last modified on 12/20/10 01:23:02 PM
Virtuoso
Get SPARQL Update working
The SPARQL user needs a special sparql_update permission.
How to insert static RDF Files
curl -T static.rdf http://localhost:8890/DAV/home/<username>/rdf_sink/static.rdf -u <username>:<password>
Why aren't all the results returned in my sparql query?
The default for SPARQL/ResultSetMaxRows is 10.000. This can be changed in the configuration.
Are there more limitations?
In file_to_string() the file size is limited to 16 MB.
Common SPARQL Queries
Namespaces
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> PREFIX dc: <http://purl.org/dc/elements/1.1/> PREFIX owl: <http://www.w3.org/2002/07/owl#> PREFIX foaf: <http://xmlns.com/foaf/0.1/>
Graphs
Show all Graphs:
SELECT DISTINCT ?g
WHERE {
GRAPH ?g {
?s ?p ?o .
}
}
ORDER BY DESC(?g)
Delete Graph:
CLEAR GRAPH <http://example.com/myGraph#>
counting
Most common 10 items (taken from different urls):
PREFIX xy: <http://example.com/xy/>
PREFIX dc: <http://purl.org/dc/elements/1.1/>
SELECT COUNT(?url), ?s
WHERE {
?sub xy:item ?s .
?sub dc:source ?url .
}
ORDER BY DESC(COUNT(?url))
LIMIT 10
Ranking
You need the Virtuoso Faceted Browser VAD package.
To calculate the rank execute the following SQL command (use webconsole or isql):
s_rank()
Example Query:
SELECT ?iri( <LONG::IRI_RANK> (?iri) ) AS ?Rank
WHERE
{
?iri ?x ?y
}
ORDER BY DESC ( <LONG::IRI_RANK> (?iri) )
LIMIT 10
More Information:
