Chapter 13: Object-Oriented Data Modeling

Object-oriented data modeling

Centers around objects and classes, involves inheritance, and encapsulates both data and behavior

Implementation

• programming

• database access

System Design

• system architecture

• subsystems

Object Design

• data structures

• algorithms

• controls

Analysis

• application

• what

Class

EER: Entity type = Object Oriented: _______

Object

EER: Entity instance = Object Oriented: _______

Inheritance of attributes

EER: Inheritance of attributes = Object Oriented: _______

Inheritance of behavior

EER: No representation of behavior = Object Oriented: _______

Unified Modeling Language (UML)

Object-oriented modeling is typically represented using

Class

An entity that has a well-defined role in the application domain, as well as state, behavior, and identity

Tangible

person, place or thing

Concept or Event

department, performance, marriage, registration

Artifact of the Design Process

user interface, controller, scheduler

Object

a particular instance of a class

behavior

Objects exhibit _____ as well as attributes

State

attribute types and values

Behavior

how an object acts and reacts

operations

Behavior is expressed through ______ that can be performed on it

Identity

Every object has a unique _____, even if all of its attribute values are the same

Class diagram

_______ shows the static structure of an object- oriented model: object classes, internal structure, relationships

Object diagram

_______ shows instances that are compatible with a given class diagram

Operation

A function or service provided by all instances of a class

Encapsulation

hiding internal implementation details

Constructor

creates a new instance of a class

Query

accesses but does not change an object’s state

Update

alters the state of an object

Class-Scope

operation applies to the class instead of an instance

Operations

______ implement the object’s behavior

Association

Named relationship among object classes

Association Role

Role of an object in an association

Association Role

The end of an association where it connects to a class

Multiplicity

How many objects participate in an association

Lower-bound…Upper-bound (0..1, 1..1, 1..*, 0..*)

Cardinalities are known as _____ in OO

Alternative multiplicity representation

specifying the two possible values in a list instead of a range

Object diagram

_______ shows associations between specific object instances

Association class

An association that has attributes or operations of its own or that participates in relationships with other classes

Association class

Associative entity in E-R model is known as ____ in OO

/ (example: /age)

Derived attribute and relationship symbol in OO

subclass, superclass

similar to subtype/supertype in EER

Complete, Incomplete

_____: total specialization - ______: partial specialization

Abstract Class

no direct instances possible, but subclasses may have direct instances

Concrete Class

direct instances possible

Disjoint

Example: An employee can only be one of these subclasses

Incomplete

Example: An employee may be none of them

italics (Example: {abstract})

Abstract is indicated by ______

Complete

Example: A patient MUST be EXACTLY one of the subtypes

Dynamic

Example: ______ means a patient can change from one subclass to another over time

Class-scope attribute

Specifies a value common to an entire class, rather than a specific value for an instance

underlining

Class-scope attribute is represented by _______

“=”

____ is initial, default value

Abstract Operation

Defines the form or protocol of the operation, but not its implementation

Method

The implementation of an operation

Polymorphism

The same operation may apply to two or more different classes in different ways

Class-scope attribute

Only one value common to all instances of these classes (includes default values)

Overriding

The process of replacing a method inherited from a superclass by a more specific implementation of that method in a subclass

Extension, Restriction, Optimization

For _______: add code - For _______: limit the method - For _______: improve code by exploiting restrictions imposed by the subclass

Multiple Classification

An object is an instance of more than one class

Multiple Inheritance

A class inherits features from more than one superclass

Aggregation

A part-of relationship between a component object and an aggregate object

Composition

A stronger form of aggregation in which a part object belongs to only one whole object and exists only as part of the whole object

Recursive Aggregation

Composition where component object is an instance of the same class as the aggregate object

aggregation, composition

Open diamond indicates _____, and closed diamond indicates _______

labeled dashed arrow from one to the other

Business rules involving two graphical symbols: _______

note with dashed lines to each symbol

Business rules involving three or more graphical symbols: _________

Superclass

The class they are generalized into (parent)

Subclass

The classes that are generalized (children)

Disjoint

A subclass that may not have subclass/es

Overlapping

A subclass that may have subclass/es