Extended DB Features
Oracle SQL Extensions
Linking Database Tables
Database Management System
Database Life Cycle
DBLC Design Stages
3 Schema Architecture
Post Design Stages
Application Approach DB Design
Database Design Strategy
Business Rules Importance
Customer Order Shipment
Define Business Objects
Data Flow Diagram
Interview Data Users
Attributes and Entities
Entities Conceptual Model
Store Entity Values
Attribute Domains Types
Rules for Creating Identifiers
Three Relationship Types
Convert m:n to 1:n
One to One Relationships
Optional Participation Relationships
Mandatory Optional Relationship
Student Class Entities
idef1x Crowsfoot Chen Models
ER diagram model Types
Three Model Types
Entity relationships - Exercise
Create simple statements for entity relationships.
This exercise is worth a total of 20 points. You will receive up to five points for each correct answer to the questions listed below.
In the preceding lesson, you learned that entity relationships are associations between entities. You also learned that simply knowing an association exists between entities reveals very little; that you must also know the
type of relationship
type of participation
that exist between entities in order to establish relationships.
The four entities (CUSTOMER, ORDER, CD, DISTRIBUTOR) for Stories on CD, Inc. participate in relationships with each other. Based on this knowledge, answer the following questions using this basic format for each response: The VENDOR entity participates in a relationship with the PRODUCT entity.
What relationship(s) does the CUSTOMER entity directly participate in?
What relationship(s) does the ORDER entity directly participate in?
What relationship(s) does the CD entity directly participate in?
What relationship(s) does the DISTRIBUTOR entity directly participate in?
The easiest way to determine entity relationships is with a sketch. Below is a partial sketch to get you started. If you transfer this sketch to a sheet of paper and (correctly) draw in the lines, you will have the answers to the exercise. Keep in mind that only those entities with a line drawn between them are
participating in that particular relationship.
Entity relationships initial sketch consisting of 1)CUSTOMER 2) DISTRIBUTOR 3)ORDER 4)CD
Submitting your exercise
Type or paste your answers into the text box below, then click
to submit your answer and view a results page.