Chapter 03: Data Modeling Using the Entity–Relationship (ER) Model

Conceptual modeling

Important phase in designing a successful database application

Database application

Refers to a particular database and associated programs for database queries and updates

BANK database application

Includes programs for database updates corresponding to customer deposits and withdrawals

Graphical user interfaces (GUIs)

Provide user-friendly interfaces utilizing forms and menus for end users

Mobile apps

Provide interfaces to BANK customers via mobile devices

Entity-relationship (ER) model

Popular high-level conceptual data model used for database applications

ER diagrams

Diagrammatic notation associated with the ER model

Unified Modeling Language (UML)

Object modeling methodology increasingly popular in database and software design

Class diagrams

Specify detailed design of software modules and interactions

Relationship types

Define associations among entities from different entity types

Entity sets

Collections of entities of a particular entity type in the database

Key attributes

Attributes whose values are distinct for each individual entity in the entity set

Value sets

Specifies the set of values that may be assigned to an attribute for each individual entity

Relationship sets

Sets of associations among entities from different entity types

Cardinality ratios

Specify the maximum number of relationship instances that an entity can participate in

Participation constraints

Specify whether the existence of an entity depends on its being related to another entity via the relationship type

Recursive relationships

Relationship types where the same entity type participates more than once in different roles

Attributes of relationship types

Can include relationship attributes that are determined by the combination of participating entities in a relationship instance