An identifier is a class attribute, or a combination of class attributes, whose values uniquely identify each occurrence of the class. It is used during intermodel generation when you generate a CDM or a PDM into an OOM, the CDM identifier and the PDM primary or alternate keys become identifiers in the OOM.
An identifier can be created for a class in the following diagrams:
Each class can have at least one identifier. Among identifiers, the primary identifier is the main identifier of the class. This identifier corresponds to a primary key in the PDM.
When you create an identifier, you can attach attributes or business rules to it. You can also define one or several attributes as being primary identifier of the class.
For example, the social security number for a class employee is the primary identifier of this class.