Post on 20-Aug-2015
Linkatu: Linked data journalism
Irekia, Bilbao 2012
“the value of your information
grows exponentially with your
ability to combine it with new
information”
– Henry Story, Sun Microsystems
http://richard.cyganiak.de/2007/10/lod/
BBC and Linked Data @metade
Document
Book
Novel Short story
http://www.bbc.co.uk/nature/life/Lion
RDF is a triple model i.e. every piece of knowledge is broken down into
( subject , predicate , object )
( doc.html , author , Fabien ) ( doc.html , theme , Music )
( subject , predicate , object )
http://inria.fr/~fabien#me
http://inria.fr/schema#author
http://inria.fr/rr/doc.html
http://inria.fr/schema#theme
Music
http://dbpedia.org/page/Lion
http://en.wikipedia.org/wiki/Lion
SPARQL stands for SPARQL Protocol and RDF Query Language
SPARQL query
SELECT ...
FROM ...
WHERE { ... }
SELECT clause
to identify the values to be returned
FROM clause
to identify the data sources to query
WHERE clause
the triple/graph pattern to be matched against the triples/graphs of RDF
WHERE clause
a conjunction of triples: { ?x rdf:type ex:Person
?x ex:name ?name }
PREFIX
to declare the schema used in the query
example persons and their names
PREFIX ex: <http://inria.fr/schema#>
SELECT ?person ?name
WHERE {
?person rdf:type ex:Person
?person ex:name ?name .
}
Example of result <?xml version="1.0"?>
<sparql xmlns="http://www.w3.org/2005/sparql-results#" >
<head>
<variable name="person"/>
<variable name="name"/>
</head>
<results ordered="false" distinct="false">
<result>
<binding name="person">
<uri>http://inria.fr/schema#fg</uri>
</binding>
<binding name="name">
<literal>gandon</literal>
</binding>
</result>
<result> ...
FILTER
to add constraints to the graph pattern (e.g., numerical like X>17 )
example persons at least 18-year old
PREFIX ex: <http://inria.fr/schema#>
SELECT ?person ?name
WHERE {
?person rdf:type ex:Person
?person ex:name ?name .
?person ex:age ?age .
FILTER (?age > 17)
}
http://data.nytimes.com/
http://linkedlifedata.com/
what is a “data market place" ?
Service that make it easy to find data from a range of secondary data sources, then consume the data in a usable and unified format. Several of these services are trying to create marketplaces for data, envisioning that data providers can offer their data sets for sale to data seekers
what is a "platform" ?
a place where we
encourage...
support...
enable...
our communities
You own the data
You control access
You can pull it/change it
You can delete it
You can decide what is best
@alabarga
alabarga@linkatu.net