RelationalDBDesign
SiteMap
Database Analysis
Database Design
Extended DB Features
Oracle SQL Extensions
Diagram Conventions
«Prev
Next»
Database Design
Database Structure
Relational Database Model
Relationally Complete
Relational Completeness
Database Structure
Linking Database Tables
SQL in RDBMS
Create Table SQL
DBMS
Database Change Management
Relational DB Structure
Database Life Cycle
Database Design Strategy
Subject Approach DB Design
Design Subject
Application Approach Design
Schema Architecture
Three Schema Arch
DBLC Design Stages
Post Design Stages
Design Tools
DB Design Strategy Conclusion
Requirements Analysis
Requirements Analysis
Define Business Objects
BO Characteristics
Business Rules Importance
Interview Data Users
Data Flow Diagram
Creating User Views
Calculated Fields
Requirements Documentation
Requirements Analysis Conclusion
Attributes and Entities
Entities Conceptual Model
Store Entity Values
Rules for Creating Identifiers
Entity Instances
Attribute Domains Types
Multivalued Attribute
Multi-Valued Attributes
Multivalued Attribute(resolve)
Entity Attribute Constraints
Module Summary
ER Diagrams
ERD Concept
Three Relationship Types
One to One Relationships
Identify one To One
One to many Relationships
Identify One to Many
Define many To Many
Identify Many To Many
Many to Many Challenges
Convert m:n to 1:n
Mandatory Optional Relationship
Optional Participation Relationships
ERD Conclusion
ERD Conventions
ER Diagram
Three Model Types
idef1x Crowsfoot Chen Models
Entity Attribute Relationship
ER Diagram Types
Crow's Foot Notation
DB Participation Types
Interview End- Users
Verbalize ER Diagram
ER diagram model Types
Accommodating Client - Exercise
Users revisited
Objective:
Revise the ER diagram to account for a new or changed business rule.
Exercise scoring
This exercise is worth a total of two points. It is auto-scored, which means you do not need to submit anything. When you have completed the exercise, simply click the
Submit
button to receive credit for the exercise and view a results page.
Background and Overview
In the preceding lesson, you learned that a completed ER diagram should be reviewed with end users in order to make any necessary modifications. In this exercise, you will revise the ER diagram for the Stories on CD database to accommodate the client's revised business rules.
Instructions
Assume you have reviewed the completed ER diagram with Ted and Lisa of Stories on CD, Inc. They are pleased with your work, but want to make an adjustment to the relationship between the CD and DISTRIBUTOR entities. Specifically, they do
not
want to store
potential
distributors in their database. Instead, they want to make sure that every distributor is associated with at least one CD.
The original one-to-many relationship diagrammed for CD:DISTRIBUTOR gave CD an optional status in the relationship. The restated business rule requires a revision to the ER diagram regarding the participation status of CD from optional to mandatory. Make the adjustment to your ER diagram.
Submitting your Exercise
This exercise does nott require you to submit anything to a tutor. When you have completed it, simply click the
Submit
button to receive full credit and view a results page.