Useful sparql queries

Virtuoso servers

1. http://computor.mit.edu:8890/sparql

Example Queries

1. Return named graphs in a virtuoso server

SELECT DISTINCT ?namedgraph ?label
WHERE {
  GRAPH ?namedgraph { ?s ?p ?o }
  OPTIONAL { ?namedgraph rdfs:label ?label }
}
ORDER BY ?namedgraph

2. Browse distinct properties

SELECT DISTINCT ?property
WHERE { [] ?property [] }
ORDER BY ?property

Note: brackets denote a syntax for blank nodes

3. Browse distinct classes

SELECT DISTINCT ?class
WHERE { [] a ?class }
ORDER BY ?class