Created on Feb. 17, 2013, 10:12 p.m. by Hevok & updated by Hevok on May 2, 2013, 5:17 p.m.
There are several different Representations of RDF.
Node-Edge-Node Triple (=Graph Representation)
Subject -Predicate-> Object
http://denigma.de/data/entry/aging http://denigma.de/data/entry/causes http://denigma.de/data/entry/cancer
N3 Notation
Simple listing of Triples
{ http://denigma.de/data/entry/aging, http://denigma.de/data/entry/causes, http://denigma.de/data/entry/cancer }
An alternative representation is the N3 Notation in which the for instance the three URI, i.e. for the resources, for Subject, Predicate and Object are separated by a comma and enclosed in curly braces. However, this gets for longer and more complicated knowledge pretty expensive.
Turtle (Terse RDF Triple Language)
The turtle language is a simplification of the N3 language. It uses URIs in angle brackets, Literals are given in quotation mark and every Triple ends with a period, while whitespaces within the Triple will be ignored.
<Subject><Property><Object> .
<Subject><Property>"Object" .
In Turtle simple Triples/Statements look like that:
<http://denigma.de/data/entry/aging>]
<http://denigma.de/data/entry/causes>]
<http://denigma.de/data/entry/cancer>].
In order to avoid long URIs there are shortcuts. For prefixes that are used rather often one has some ways to define certain prefixes via declaring a namespace:
@prefix xsd: <http://www.w3.org/2001/XMLSchema#>] .
@prefix dc: <http://purl.org/dc/elements/1.1/>] .
@prefix ex: <http://example.org/stuff/1.0>] .
<http://www.w3.org/TR/rdf-syntax-grammar>]
dc:title "RDF/XML Syntax Specification (Revised)"@en ;
ex: editor [
ex:fullname "Dave Beckett"^^xsd:string ;
ex:homePage <http://purl.org/net/dajobe/>]
].
So prefixes will be substituted in the statements. Here editor defines a blank node with Value and a resources associated to it.
RDF XML-Serialization*
Example:
<xml version="1.0" encoding="utf-8">
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntaz-ns#"
xmlns:prof="http://denigma.de/profiles/">]
<rdf:Description rdf:about="http://denigma.de/Hevok>]
<prof:hasPhoneNr>"++49-123-1234-123"</prof:hasPhoneNr>
<rdf:Description>
<rdf:Description rdf:about="http://denigma.de/Hevok">]
<prof:hasBlog rdf:resource="http://denigma.de/blog/" />]
<rdf:Description>
</rdf:RDF>
Shortcut version with base Definition:
<xml version="1.0" encoding="utf-8">
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntaz-ns#"
xmlns:prof="http://denigma.de/profiles/">]
xml:base="http://denigma.de/">]
<rdf:Description rdf:about="Hevok
prof:hasPhoneNr>"++49-123-1234-123"</prof:hasPhoneNr>
<prof:hasBlog rdf:resource="blog" />
<rdf:Description>
</rdf:RDF>
If there is not base URI, relatives paths refer to the URI where the Document itself is located.
Comment on This Data Unit