Figure 3-10: Projects in UML
Ok, you now have the basic elements required for an entity/relationship model: the entity class, the relationship, and the attribute.
This is all you need from UML to create an equivalent entity/relationship model.
Nothing else is required.
UML has a number of features to describe concepts important to object-oriented designers and programmers. These are features that have no place in a conceptual entity/relationship diagram. They include:
· Abstract Entities – In UML, every instance of an “abstract entity” is defined to be at least one of its sub-types. That is, the super-type is an abstraction, with no physical existence apart from its sub-types. Based on the constraints described ...