CODEWITHSUNDEEP
rdfsemantic-webrdfsblank-nodes
Anmol Kagrecha
Anmol Kagrecha

Reputation: 153

Can a Blank Node have rdf:type property?

Is it valid to form the following triple:

_:bn rdf:type foaf:name

where _:bn is a blank node?

I read the W3C standards for rdf:type. It says that the rdfs:domain of rdf:type is rdfs:resource. rdfs:resource is the the class of everything.

So is it correct to assign a rdf:type for a blank node?

Upvotes: 3

Views: 621

Answers (2)

bdulac
bdulac

Reputation: 1666

For a more generic answer, a blank node is a purely abstract "thing" being provided by a graph database.

Giving a type to a node means creating a triple, in other words providing a property to a subject.

subject= my blank node
property=rdf:type 
object=foaf:name

A blank node might not have an identifier but starts being a concrete "thing" when it becomes the subject of properties.

The absence of an identifier is not definitely a problem for considering the node to be a resource as it might later be associated to the node via another triple. e.g. (using the appropriate Dublin Core property for an identifier) :

subject= my blank node
property=http://purl.org/dc/terms/subject
object=http://my-testdomain.com/my-url

Upvotes: 2

user205512
user205512

Reputation: 8888

Yes, it's absolutely fine. Blank nodes are simply things without a URL identifier. (Well it's a little more complex, but I wouldn't worry about it)

Like a car without a registration plate, it doesn't stop them doing anything cars with plates can do.

But it makes life difficult for people trying to work out whether they've seen the same car, or find the car.

Upvotes: 5

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