OBJECT-BASED DATA MODEL: PRINCIPLES AND COMPONENTS - Database Design and Development: An Essential Guide for IT Professionals - page 171

CUSTOMER: Customer Number (preassigned)
DEPOSIT: Transaction Number
Relationships Indicate relationships, with diamond shapes, between
CHECKING ACCOUNT and CUSTOMER, CHECKING ACCOUNT and
DEPOSIT, CUSTOMER and DEPOSIT.
Cardinalities Number to show cardinalities at either side of the diamonds for
the above relationships.
Generalization/Specialization Show notations to indicate superset ACCOUNT
and subset CHECKING ACCOUNT.

Medical Insurance Claims Processing

Business Objects Show object boxes for INSURED, POLICY, AGENT, and

CLAIM.
Attributes Show attribute ellipses for characteristics of the above four objects.
Identifiers Show attribute ellipses for the following identifiers, underlining the
attribute names within the ellipses:
INSURED: Social Security Number
POLICY: Policy Number
CLAIM: Claim Number (assigned)
AGENT: AGENT ID (assigned)
Relationships Indicate relationships, with diamond shapes, between INSURED
and POLICY, AGENT and POLICY, CLAIM and POLICY.
Cardinalities Number to show cardinalities at either side of the diamonds for
the above relationships.
Generalization/Specialization

None required.

Example of a Model Diagram

From the above real-world information requirements and their mapping to the
object-based data model, you have a glimpse of how the model is created and the
model diagram drawn. Note, however, that we have just introduced the principles;
we have not gone into too many details or dealt with any complexities in the real-
world business situations. Nevertheless, you now have a more concrete notion about
how a model represents real-world information.
The subsequent sections of this chapter elaborate on the individual model com-
ponents. Before getting into a discussion of the details, let us take a specific example
of real-world information about a small group practice of surgeons, review a data
model diagram, and note the components. The description of the group practice
operations and information requirements follows:
Three orthopedic surgeons, Dr. Samuel J. Laufer, Dr. Andrew Bowe, and Dr. Lisa
Sanderson, have joined together to form Orthopedic Associates P.A. They want to
install a computer system for their group practice. They also want to use a database
for their information requirements. Initially, the database is required to support just
the billing function.