Object Identifiers

A core concept of our knowledge graph is that each object in the graph has a unique and global URI identifier. An object node is a node in the graph that has further attributes. By default, each object in the graph has a type information ( rdf:type statement) and a link to a Domain specification ( a ds:compliesWith statement), which was used to verify the structure and shape of the object.

These URI object identifiers are also used to retrieve, update or delete the object.

Identifier format

A URI identifier is a syntactically valid URI. We distinguish between two parts of an URI: the namespace and the localName.

A namespace is the first part of a URI until the last "/" or "'#", the local name is the part of the URI after the namespace.

For example, given the url http://example.com/entity/uuid, the namespace would be http://example.com/entity, and the localname would be uuid

Identifier generation

There are basically two ways to generate such object URI identifiers in the platform.

  1. The system assigns a global and unique identifier or
  2. The client provides the identifier during the creation or update of the data

Random system identifier if missing

The system assigns each object, that is missing an identifier, a random system identifier.

The created and assigned identifiers will be listed in the response of the operation (see also Import Report).

Assign an external identifier

The other option is that the client provides object identifiers in the data - either identifiers which where already assigned by the system in previous imports, or an identifier the client created.

What’s Next

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