Skip to content

Repository files navigation

Database Design & SQL Practice

This repository contains my hands-on practice while learning Database Design and SQL Server.

It includes database design projects, ERDs, relational schemas, and solutions to SQL challenges that helped me strengthen my understanding of relational databases and SQL.

Background

I started this repository with no prior knowledge of database design or SQL.

It documents my learning journey through designing relational databases and solving practical SQL problems. Each database design was compared against a reference solution to validate the ERD and relational schema and identify areas for improvement.

For the SQL exercises, I often challenged myself to solve the same problem using different approaches instead of stopping at the first working query. This helped me better understand SQL concepts and the tradeoffs between different query techniques.


Topics Covered

  • Relational Database Design
  • Entity Relationship Diagrams (ERD)
  • Relational Schema
  • Database Normalization (1NF, 2NF & 3NF)
  • SQL (DDL & DML)
  • Joins
  • Aggregate Functions
  • GROUP BY & HAVING
  • Views
  • Constraints
  • Indexes
  • CASE Expressions
  • EXISTS
  • Subqueries
  • Self Joins
  • Data Filtering & Sorting

Repository Structure

Database-Design-and-SQL-Practice/
│
├── 01-Simple-Clinic/
├── 02-Simple-Library/
├── 03-Karate-Club/
├── 04-Car-Rental/
├── 05-Online-Shop/
└── SQL-Problems/

Database Design Projects

This repository contains five database design projects:

  • Simple Clinic
  • Simple Library
  • Karate Club
  • Car Rental
  • Online Shop

Each project includes:

  • Entity Relationship Diagram (ERD)
  • Relational Schema
  • Original Draw.io source file

SQL Practice

The SQL-Problems folder contains solutions to more than 50 SQL exercises, covering:

  • SELECT Statements
  • WHERE, IN & BETWEEN
  • ORDER BY
  • Aggregate Functions
  • GROUP BY & HAVING
  • CASE Expressions
  • EXISTS
  • Views
  • INNER, LEFT, RIGHT & FULL JOIN
  • Subqueries
  • Self Joins
  • Data Analysis Queries

The exercises use real-world datasets to practice writing efficient SQL queries and solving practical database problems.


Repository Highlights

  • ✅ Designed five relational database projects from business requirements.
  • ✅ Created ERDs and converted them into relational schemas.
  • ✅ Solved 50+ SQL practice problems.
  • ✅ Explored multiple SQL solutions for the same problem to strengthen problem-solving skills.

Tools Used

  • Microsoft SQL Server
  • SQL Server Management Studio (SSMS)
  • Draw.io

About

Database design projects and SQL Server practice covering ERDs, relational schemas, normalization, and 50+ SQL challenges.

Topics

Resources

Stars

Watchers

Forks

Releases

Packages

Contributors