8 – Integrating Objects

Publisher Summary This chapter concerns with the way in which a number of relational products have integrated aspects of the object-oriented data model. The relational data model has been a mainstay of business data processing for nearly 30 years. Nothing has superseded it the way the relational data model superseded the simple network data model. However, a newer data model—the object-oriented data model—has come into use as an alternative for some types of navigational data processing. The object-oriented paradigm was the brain child of Dr. Kristen Nygarrd. To understand the role of objects in relational databases, the object-oriented paradigm should be understood as it is used in object-oriented programming. An object-oriented program is made up of a collection of objects, each of which has attributes and methods. The objects interact by sending messages to one another. The trick, of course, is to figure out exactly which objects a program needs, and the attributes and methods those objects should have. When a program creates an object from a class, it provides data for the object's variables. The object can then use the methods that have been written for its class. All of the objects created from the same class share the same procedures for their methods. They also have the same types of data, but the values for the data may differ.