Database Reference
In-Depth Information
Examples:
Object Set
EMPLOYEE
Instances
John Doe, Mary Smith, Jane Williams, Maryanne Rogers
Object Set
CUSTOMER
Instances
Harold Epstein, Bill Richardson, Walker Electricals, Inc., Jerry
Philips and Sons, Inc.
Object Set
PRODUCT
Instances
Coat, slacks, shirt, dress, socks, hat, gloves
Object Set.
INVOICE
Instances.
No.1234 dated 10/15/2002, No.2345 dated 12/23/2002, No.3456 dated
1/10/2003
Object Set
BUILDING
Instances
121 Main Street, 33 Park Avenue, 101 Center Boulevard, 25 Ray
Road
Types of Objects
We have gone through several examples of business objects and their instances. You
now have a fairly good understanding of objects represented in a data model. You
have seen that EMPLOYEE is a business object. You have also noted that
PRODUCT, INVOICE, and BUILDING are objects as well. What then are objects?
What are the various types of objects? How do you differentiate between one type
of object and another?
A person, as in the case of EMPLOYEE, is an object. A BUILDING is a mate-
rial object. In the case of INVOICE, it is neither a person nor a material. When you
refer to the object INVOICE, you do not indicate the piece of paper on which the
invoice details are printed and sent to the customer. The piece of paper is a mani-
festation of a single instance of the object INVOICE. What then is the object
INVOICE? It is a concept that covers the billing to a customer for services or
products.
Listed below are the common types of objects:
Person
EMPLOYEE, STUDENT, PATIENT
Place
STATE, COUNTRY, REGION
Material
MACHINE, PART, PRODUCT, BUILDING
Event
SALE, VISIT, APPOINTMENT
Concept
ACCOUNT, COURSE, INVOICE
Recognizing Object Sets
Let us say that you have the responsibility for examining the information require-
ments of a department store and creating an object-based data model. As you very
well know, business objects are the fundamental building blocks for creating the
model. So, by inspecting the requirements definition, you must first recognize the
business objects that are relevant. How do you accomplish this initial task?
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