1 / 35

Chapter 4: The Enhanced ER Model and Business Rules

2. Objectives. Definition of termsUse of supertype/subtype relationshipsUse of generalization and specialization techniquesSpecification of completeness and disjointness constraintsDevelop supertype/subtype hierarchies for realistic business situationsDevelop entity clustersExplain universal d

sela
Download Presentation

Chapter 4: The Enhanced ER Model and Business Rules

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

    1. © 2007 by Prentice Hall 1 Chapter 4: The Enhanced ER Model and Business Rules Modern Database Management 8th Edition Jeffrey A. Hoffer, Mary B. Prescott, Fred R. McFadden

    2. 2 Objectives Definition of terms Use of supertype/subtype relationships Use of generalization and specialization techniques Specification of completeness and disjointness constraints Develop supertype/subtype hierarchies for realistic business situations Develop entity clusters Explain universal data model Name categories of business rules Define operational constraints graphically and in English

    3. 3 Supertypes and Subtypes Subtype: A subgrouping of the entities in an entity type that has attributes distinct from those in other subgroupings Supertype: A generic entity type that has a relationship with one or more subtypes Attribute Inheritance: Subtype entities inherit values of all attributes of the supertype An instance of a subtype is also an instance of the supertype

    4. 4

More Related