annotate tests/misc-queries/test-query-pluginid-for-rdf @ 19:bd1deebe1129

* Set track metadata only if non-empty (the RDF feature writer tests for
  existence rather than non-emptiness when determining whether to write
  a track)

PREFIX vamp: <http://purl.org/ontology/vamp/>
PREFIX examples: <http://vamp-plugins.org/rdf/plugins/vamp-example-plugins#>

SELECT ?plugin ?library_id ?plugin_id
FROM <http://vamp-plugins.org/rdf/plugins/vamp-example-plugins>

WHERE {
      ?plugin a vamp:Plugin .
      ?plugin vamp:identifier ?plugin_id .
      OPTIONAL { ?library a vamp:PluginLibrary .
            ?library vamp:identifier ?library_id .
	          ?library vamp:available_plugin ?plugin . }
}