Subject-predicate-object triples (or simply triples) are the main form of knowledge representation in RDF, the language of the semantic web. Becasue of this RDF databases are often referd to has triple stores. Although the triple seems verey simple, it can dscribe anything that more complex representations such as tables, XML or JSON data structures Some RDF databases also stupport named graphs, where triples are tagged with a graph URI, and hence are called quad stores.
An example:
| subject | predicate | object | ||
|---|---|---|---|---|
| Scooby Doo | –- | instance of | –- | Great Dane |
| Dog | –- | number of legs | –- | 4 |
In RDF the subject and predicate must both be URIs, like this:
| <https://alandix.com/> | <dc:creator> | "Alan Dix" |
| <aibk:Scooby_Doo> | <rdf:type> | <aibk:Great_Dane> |
| <aibk:Dog> | <aibk:number_of_legs> | "4"^^xsd:integer |
Used on page 392