The Web, one huge database ...

In an attempt to reaching out to the Web developers (called 'Hacker Joe', here ;) I've compiled a screen-cast on how one can understand the Web as a huge database. The screen-cast starts out with a bit of explanation of some essentials, however, the bigger part of it is dedicated to two hands-on examples: first we query and use data from DBPedia (the linked data version of Wikipedia) and then we look into a heavily distributed linked data form, that is, using a FOAF profile we again query and use data from there.

Note that the accompanying slides are available as well via slideshare. In case you want to test the queries used in the screen-cast along with the endpoints, here you are ...

DBpedia Example

SELECT ?typedlink ?value {

  <http://dbpedia.org/resource/Darth_Vader> ?typedlink ?value .

  FILTER isURI(?value)

}

In order to try it out, go to http://dbpedia.org/sparql, paste it in and execute it.

FOAF Profile Example

PREFIX foaf: <http://xmlns.com/foaf/0.1/>

SELECT ?acquaintance ?acquaintanceName 

FROM <http://www.w3.org/People/Berners-Lee/card>

WHERE {

 <http://www.w3.org/People/Berners-Lee/card#i> foaf:knows ?acquaintance .

 ?acquaintance foaf:name ?acquaintanceName . 

 FILTER isURI(?acquaintance)

}

In order to try out this example, go to http://sparql.org/sparql.html, paste the above SPARQL query in and execute it.

More Of This Stuff

• Turn Twitter Into Your Personal Assistant
• The Real Deal: data.gov.uk
• Modeling your data with DBpedia vocabularies
• SPARQL By Example
• Further guides and tutorials on linked data

Kudos to Tuukka Hastrup, who provided immediate feedback and made me put the slides and the code fragments online as well ;)