SQL Practice Repository

A structured, beginner-friendly collection of SQL exercises and practice problems designed to help you master Structured Query Language — from basic queries to advanced topics like window functions, CTEs, and query optimization.

📁 Repository Structure

sql-practice/
│
├── README.md                 # You are here
├── .gitignore                # Ignored files for SQL projects
├── schema.sql                # Database schema (Employee & Department tables)
├── sample_data.sql           # Realistic sample data for practice
├── progress.md               # Track your learning progress
│
├── basics/                   # Fundamental SQL queries
│   ├── select.sql
│   ├── where.sql
│   ├── order_by.sql
│   ├── limit.sql
│   └── distinct.sql
│
├── filtering/                # Filtering techniques
│   ├── like.sql
│   ├── between.sql
│   ├── in.sql
│   └── null.sql
│
├── sorting-grouping/         # Sorting and aggregation
│   ├── group_by.sql
│   ├── having.sql
│   └── aggregate_functions.sql
│
├── joins/                    # Joining tables
│   ├── inner_join.sql
│   ├── left_join.sql
│   ├── right_join.sql
│   ├── full_join.sql
│   └── self_join.sql
│
├── advanced/                 # Advanced SQL concepts
│   ├── subqueries.sql
│   ├── cte.sql
│   ├── window_functions.sql
│   ├── case.sql
│   └── views.sql
│
├── interview_questions/      # Practice interview-style SQL problems
└── notes/                    # Your personal SQL notes

🚀 Prerequisites

To run these SQL files, you'll need one of the following:

• MySQL (version 8.0+ recommended)
• PostgreSQL (version 12+ recommended)
• SQLite (for lightweight practice)
• Any SQL database of your choice

Recommended Tools

• MySQL Workbench – GUI for MySQL
• pgAdmin – GUI for PostgreSQL
• DBeaver – Universal database tool
• VS Code with SQL extensions (like SQLite Viewer or MySQL)

🛠️ How to Use This Repository

1. Clone or download the repository

git clone https://github.com/your-username/sql-practice.git
cd sql-practice

2. Set up the database

Run the schema file to create the tables:

MySQL / PostgreSQL:

source schema.sql;

SQLite:

sqlite3 practice.db < schema.sql

3. Load sample data

source sample_data.sql;

4. Start practicing

Open any .sql file in your preferred SQL editor and start writing your queries in the placeholder sections provided.

5. Test your queries

-- Example: Run a SELECT query
SELECT * FROM Employee;
SELECT * FROM Department;

📚 Topics Covered

Topic	Files
Basics	SELECT, WHERE, ORDER BY, LIMIT, DISTINCT
Filtering	LIKE, BETWEEN, IN, NULL handling
Sorting & Grouping	GROUP BY, HAVING, Aggregate Functions
Joins	INNER JOIN, LEFT JOIN, RIGHT JOIN, FULL JOIN, SELF JOIN
Advanced	Subqueries, CTEs, Window Functions, CASE, Views

📊 Sample Schema

The repository includes two primary tables:

Employee

Column	Type	Description
emp_id	INT (PK)	Unique employee ID
emp_name	VARCHAR	Employee full name
job_title	VARCHAR	Job position
manager_id	INT (FK)	Reports to (self-referencing)
date_hired	DATE	Hire date
salary	DECIMAL	Monthly salary
dept_id	INT (FK)	Department ID

Department

Column	Type	Description
dept_id	INT (PK)	Unique department ID
dept_name	VARCHAR	Department name
location	VARCHAR	Office location

✅ Progress Tracking

Use progress.md to track which topics you've completed and add notes about what you've learned.

🤝 Contributing

This is a personal practice repository, but feel free to fork it and adapt it for your own learning journey!

📄 License

This project is for educational purposes. Feel free to use and modify it.