I was always wonder if we can extract structured data from Wikipedia. I stumbled up on DBPedia and SPARQL. DBPedia stores Wikipedia data as Dataset and it can be accessed using SPARQL. Let me demonstrate this with an example.

DBPedia has a SPARQL endpoint . And you can use SNORQL for exploring DBPedia. Let us execute the below SPARQL query in SNORQL and notice the resultset that is returned,

PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX foaf: <http://xmlns.com/foaf/0.1/>

SELECT DISTINCT ?film_title ?star_name
where {?film_title rdf:type <http://dbpedia.org/ontology/Film> .
?film_title  foaf:name ?film_name .
?film_title rdfs:comment ?film_abstract .
?film_title dbpedia-owl:starring ?star .
?star dbpprop:name ?star_name
}
LIMIT 5

I get the results as below,

SPARQL results from DBPedia

As good place to learn SPARQL is http://answers.semanticweb.com/ .

I hope this article helps you.