Looking for green plants

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 <http://dbpedia.org/resource/Category:Drugs>
}

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:ordo :Carnivora
}

All married kernel hackers:

SELECT ?a, ?b WHERE {
  ?a skos:subject <http://dbpedia.org/resource/Category:Linux_kernel_hackers> .
  ?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
}