Looking for green plants

    oever's picture
    2008
    25
    Jul

    Do you know about DBpedia? It's a project that lets you perform complex queries on the content of wikipedia. I've been playing with it a bit and want to share some examples. Try to come up with cool queries!

    To query DBpedia, there is convenient form. Queries are performed in SPARQL. SPARQL is a query language that takes some getting used to. So I'll start with a few simple examples.

    A query for all articles with an image:
    SELECT ?a, ?b WHERE {
    ?a foaf:img ?b
    }

    A list of all drugs:
    SELECT ?a WHERE {
    ?a skos:subject
    }

    Everything with an LGPL license:
    SELECT ?a WHERE {
    ?a dbpedia2:license "LGPL"@en
    }

    All translations of 'Chair':
    SELECT ?a WHERE {
    :Chair rdfs:label ?a
    }

    All carnivors that had their name stolen:
    SELECT ?a, ?b WHERE {
    ?a dbpedia2:disambiguates ?b .
    ?a dbpedia2:regnum :Animal
    }

    All married kernel hackers:
    SELECT ?a, ?b WHERE {
    ?a skos:subject .
    ?a dbpedia2:spouse ?b
    }

    All pages that redirect to a plant:
    SELECT ?a, ?b WHERE {
    ?a dbpedia2:redirect ?b .
    ?b dbpedia2:regnum :Plant
    }

    A query for all green plants:
    SELECT ?a WHERE {
    ?a dbpedia2:regnum :Plant .
    ?a dbpedia2:color "green"@en
    }