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rdfsparqlsemantic-webdbpedia

How to query dbpedia by property type value,

I am trying to write a SPARQL query to retrieve all pages that are linked to neighborhoods on Wikipedia. An example is http://live.dbpedia.org/page/Carter_Crest,_Edmonton. The property type is http://dbpedia.org/property/settlementType where settlementType should be "neighbourhood", the other option is template:infobox_settlement. So far, I've tried the following:

SELECT ?property ?hasValue ?isValueOf
WHERE {
  { <http://dbpedia.org/ontology/Settlement> ?property ?hasValue }
  UNION
  { ?isValueOf ?property <http://dbpedia.org/ontology/Settlement> }
}


SELECT ?class ?label
WHERE {
  ?class rdf:type owl:Place.
  ?class rdfs:label ?label. 
  FILTER(lang(?label) = "Neighbourhood")
}
Solution

  • <http://dbpedia.org/ontology/Settlement> is the IRI of the type Settlement. Any particular settlement, such as Carter Crest, Edmonton, is an instance of that type.

    By writing

    <http://dbpedia.org/ontology/Settlement> ?property ?hasValue

    you look for properties that are linked to the type Settlement, rather than to any instances of it. What you are looking for is any property that is linked to an arbitrary object of type Settlement:

    ?someObject ?property ?hasValue.
?someObject a <http://dbpedia.org/ontology/Settlement>.

    In your second query, what you are currently retrieving is any instance of type owl:Place, whose textual description equals Neighbourhood (which sounds like a type again, rather than a specific thing).

    However, you probably want to retrieve an instance whose type's label equals Neighbourhood. (And actually, you probably don't actually want to do that, either; that would be wild guessing that the type labeled Neighbourhood is what you are looking for. If you know the concrete type IRI, search for that as above.)