Relational Data Model

Introduction

A relational data model organizes data into tables, with each table representing a relation.

Components

• Tables (Relations): Collections of related data, represented as rows and columns.
• Rows (Tuples): Individual records or entries in a table.
• Columns (Attributes): Characteristics or properties of the data in a table.
• Primary Key: Unique identifier for each row in a table.
• Foreign Key: Field in a table that references the primary key of another table.

Relationships

• One-to-One (1:1): One row in one table is related to only one row in another table.
• One-to-Many (1:N): One row in one table is related to multiple rows in another table.
• Many-to-Many (M:N): Multiple rows in one table are related to multiple rows in another table.

Benefits

• Data Integrity: Relational data models enforce data integrity through constraints and relationships.
• Data Flexibility: Relational data models allow for flexible data retrieval and manipulation.
• Scalability: Relational data models can handle large amounts of data and support multiple users.

Relational Algebra

• Selection: Retrieves specific rows from a table.
• Projection: Retrieves specific columns from a table.
• Join: Combines rows from two or more tables based on a related column.