DATABASE Module 7-8

Data Modeling

process of creating a conceptual representation of data, typically in the form of a data model.

Best Practices for Building Data Models (1/8)

Understanding the business requirement

Best Practices for Building Data Models (2/8)

Use a consistent naming convention

Best Practices for Building Data Models (3/8)

Avoid data rebundancy

Best Practices for Building Data Models (4/8)

Enforce data integrity

Best Practices for Building Data Models (5/8)

Use appropriate data types

Best Practices for Building Data Models (6/8)

Test and validate the model

Best Practices for Building Data Models (7/8)

Document the model

Best Practices for Building Data Models (8/8)

Review and update the data model regularly

Types of data models

1. Conceptual Data Model

2. Logical Data Model

3. Physical Data Model

Conceptual Data Model

high-level representation of the data and the relationships between them. Understand the overall structure of the data

Logical Data Model

more detailed representation of the data, includes information about entities, attributes, and relationships. Is technology-independent

Physical Data Model

final/most detailed representation of the data, includes information about specific technology and database will be used to store the data.

Conceptual vs Logical vs Physical Model

Object Oriented Databases

Represents data as objects and classes

Relational Databases

Represents data in tables and rows

Database Design

process of creating a structured plan how data will be stored, organized, accessed within database

Steps in Database Design Process (GCCTCPI)

Gathering

Creating Conceptual

Translating

Creating Physical

Implementation

Three Main types or Relationships in Database Design

One to one R

One to many

Many to many

Components of Entity Relationship Diagram

Entities

Attributes

Relationships

Cardinality

Connectivity

Participation

Keys

Visual Representation ER Models

Rectangle - Entity

Elipses - Attributes

Diamonds - Relationships

Lines - Connect entities

Crow’s Foot notation - Indicate cardinality

Dashed lines - Indicare weak or optional R

Primary Key notation

Foreign Key notation