/SQL

Database Normalization Project

Overview

This project demonstrates the process of normalizing a database schema to remove redundancy and improve data integrity. The project covers three levels of normalization: First Normal Form (1NF), Second Normal Form (2NF), and Third Normal Form (3NF). Each normalization step is provided with SQL scripts and explanatory documentation.

Files

  • 1NF.sql - SQL script for creating tables in First Normal Form.
  • 1NF.md - Documentation explaining the design and structure of the 1NF schema.
  • 2NF.sql - SQL script for creating tables in Second Normal Form.
  • 2NF.md - Documentation explaining the design and structure of the 2NF schema.
  • 3NF.sql - SQL script for creating tables in Third Normal Form.
  • 3NF.md - Documentation explaining the design and structure of the 3NF schema.

Normalization Steps

First Normal Form (1NF)

Objective: Ensure that each column contains atomic values and there are no repeating groups.

  • File: 1NF.sql
  • Description: This script creates tables with atomic values, breaking down multiple values in a single column into separate rows.
  • Example:
    • Initial Table: Books with columns for multiple authors and genres.
    • Normalized Tables: Separate tables for books, authors, and genres.
  • Documentation: 1NF.md

Second Normal Form (2NF)

Objective: Ensure that all non-key attributes are fully functionally dependent on the entire primary key.

  • File: 2NF.sql
  • Description: This script splits the table to remove partial dependencies, resulting in separate tables for customers, orders, and products.
  • Example:
    • Initial Table: Orders with customer details and product details.
    • Normalized Tables: Separate tables for customers, orders, and products.
  • Documentation: 2NF.md

Third Normal Form (3NF)

Objective: Ensure that all non-key attributes are functionally dependent only on the primary key and not on other non-key attributes.

  • File: 3NF.sql
  • Description: This script further normalizes the schema to ensure that department details are only stored in a dedicated departments table, with employee details referencing it.
  • Example:
    • Initial Table: Employees with department details.
    • Normalized Tables: Separate tables for employees and departments.
  • Documentation: 3NF.md

Usage

  1. Setup Database:

    • Execute the SQL scripts in the order of normalization (1NF -> 2NF -> 3NF) to create and populate the tables.

  2. Review Documentation:

    • Read the corresponding .md files for detailed explanations of each normalization step.

Contributing

If you have suggestions for improvements or additional normalization steps, feel free to contribute!

License

This project is licensed under the MIT License - see the LICENSE file for details