Interrogation
Get flash to fully experience Pearltrees
This is intended to be a crash course for a techie/programmer who needs to learn the basics ASAP. It is not intended as an introduction for managers or policy makers (I suggest looking at Tim Berners-Lee's TED talks if you want the executive summary). It's primarily aimed at people who're tasked with creating RDF and don't have time to faff around. It will also be useful to people who want to work with RDF data. RDF is a data structure perfect for people creating mash-ups!
Linked Data Guide for Newbies - OpenOrg
RDF is a directed, labeled graph data format for representing information in the Web. This specification defines the syntax and semantics of the SPARQL query language for RDF. SPARQL can be used to express queries across diverse data sources, whether the data is stored natively as RDF or viewed as RDF via middleware.
SPARQL Query Language for RDF
Now that we’ve published nearly 10,000 of our tags as Linked Open Data , you’re probably wondering what kind of cool applications you can build with this data. To help you get started (and since linked data applications are a little different from your average Web application), we thought we’d provide a sample application and detailed information about how we built it. When the user selects the name of an institution from the auto-complete field, the application queries DBpedia for the NYT identifiers of all the alumni of that institution.
Build Your Own NYT Linked Data Application - NYTimes.com
Semantic web tutorial: RDF, RDFS and SPARQL using CORESE
This semantic web tutorial gives a quick tour of RDF, RDFS, SPARQL and Rules. It was designed as a hand-on-keyboard introduction to the basics of RDF model , RDFS semantics for lightweight ontologies, OWL Lite semantics for lightweight ontologies, SPARQL query language for RDF graph bases and production rules for knowledge factorisation in semantic web annotation bases. RDF is a triple model where every assertion is decomposed in three parts: (subject, predicate, object) for instance (tutorial.php, author, "Fabien") . The subject is URI identifying a resource. The predicate is a binary relation identified by a URI. The object is either a URI identifying a resource or a literal value.
RDF est un format de données de graphe orienté et étiqueté pour représenter des informations dans le Web. Cette spécification définit la syntaxe et la sémantique du langage d'interrogation SPARQL pour RDF . SPARQL peut être utilisé pour exprimer des interrogations à travers diverses sources de données, que les données soient stockées nativement comme RDF ou vues comme du RDF via un logiciel médiateur (middleware) . SPARQL est capable de rechercher des motifs de graphe (graph patterns) obligatoires et optionnels ainsi que leurs conjonctions et leurs disjonctions. SPARQL gère également le test extensible des valeurs et la contrainte des interrogations par un graphe RDF source. Les résultats des interrogations SPARQL peuvent être des ensembles de résultats ou des graphes RDF .