Attribute - modelint/shlaer-mellor-metamodel GitHub Wiki

β€œAn attribute is the abstraction of a single characteristic possessed by all the entities that were, themselves, abstracted as a Class.” MB.

images/class-attribute-subsystem/attribute-10.png

The complete set of Attributes in a Class should be meaningful for all instances of that Class at all times. This means that each instance of a Class provides a value for each of its Attributes under all circumstances. Concepts like not applicable or NULL mark the absence of any value and are consequently illegal.

This rule maintains consistency with the underlying relational model of data.

Identifiers

  1. Name + Class + Domain

No two Attributes share the same name within a Class.

Attributes

No non-referential attributes