5 RECORDING INFORMATION ABOUT THINGS
This chapter introduces the related concepts of the attribute, the unique identifier and the domain, and their representation on both entity relationship models and class models. The object-oriented concept of the operation is also introduced at the end of the chapter.
REVISITING ENTITY TYPES, OBJECT CLASSES, RELATIONSHIPS AND ASSOCIATIONS
Figure 5.1 The previous models
Until now we have only seen entity types or objects classes and the relationships or associations between them.
Entity types or object classes represent the things of interest ...