Database Systems: Design, Implementation, & Management
Database Systems: Design, Implementation, & Management
12th Edition
ISBN: 9781305627482
Author: Carlos Coronel, Steven Morris
Publisher: Cengage Learning
Expert Solution & Answer
Book Icon
Chapter 4, Problem 13RQ

Explanation of Solution

Composite entity:

A composite entity is normally used to convert M: N relationships into 1: M relationships. It is also referred as “bridge entity”, which has a primary key (PK) composed of multiple attributes.

  • The PK attributes are inherited from the entities, which it associates to one another.

Usage of composite entity in ERD:

In the Entity Relationship Management (ERM), an M: N relationship is effective at the conceptual level. But when implementing the ERM in a relational database, the M: N should be mapped to a set of 1: M relationships using “composite entity”.

Example:

Consider the entities CLASS and STUDENT with M: N relationship defined by following business rules:

  • A student can take several classes...

Blurred answer
Students have asked these similar questions
What exactly are entity-relationship diagrams, and how do they come into play? What kind of symbol is utilized to represent a relationship? What is an associative entity, and how does it work? Give an illustration of your point.
In an ERD, how is a connection between two or more entities indicated? Provide an example of the Crow's Foot notation in action.
What is the definition of an Entity set?
Knowledge Booster
Background pattern image
Recommended textbooks for you
Text book image
Database Systems: Design, Implementation, & Manag...
Computer Science
ISBN:9781305627482
Author:Carlos Coronel, Steven Morris
Publisher:Cengage Learning
Text book image
Principles of Information Systems (MindTap Course...
Computer Science
ISBN:9781285867168
Author:Ralph Stair, George Reynolds
Publisher:Cengage Learning
Text book image
Database Systems: Design, Implementation, & Manag...
Computer Science
ISBN:9781285196145
Author:Steven, Steven Morris, Carlos Coronel, Carlos, Coronel, Carlos; Morris, Carlos Coronel and Steven Morris, Carlos Coronel; Steven Morris, Steven Morris; Carlos Coronel
Publisher:Cengage Learning
Text book image
Oracle 12c: SQL
Computer Science
ISBN:9781305251038
Author:Joan Casteel
Publisher:Cengage Learning