Querying a dataset with inconsistent properties

Hi,

I'm constructing a query to fetch SKOS concepts from a set of
concepts. I'm looking to return each concept with all of its
statements, e.g. prefLabel, altLabel, etc. I was using the following
query, specifying the symbol mapping:

RDF::Query.new concept: {
  RDF.type => RDF::SKOS.Concept,
  RDF::SKOS.prefLabel => :prefLabel,
  RDF::SKOS.altLabel => :altLabel,
  RDF::SKOS.broader => :broader,
  RDF::SKOS.related => :related,
  RDF::SKOS.scopeNote => :scopeNote
}

However, this only returns concepts which have *each* of those
properties - it ignores, for example, concepts which have no `related`
predicates. What would be the best query to use to fetch all concepts
and their properties?

Best,
Misty De Meo

Received on Friday, 20 December 2013 10:45:44 UTC