SQL Query Practice Trainer

A local SQL trainer that runs in your browser. Practice real queries on a real database, no sign-up, no cloud.

Quick Start

git clone https://github.com/burgano/SQL-query-practice.git
cd sql-query-practice

macOS / Linux:

bash run.sh

Windows:

run.bat

The script sets everything up automatically and opens the browser. No manual installation needed.

To stop the server use the Stop server button inside the app.

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Platform notes

macOS

• Requires Python 3.8+ — python.org
• Creates a virtual environment, installs dependencies, starts the server
• Browser opens automatically at http://localhost:<port>
• Port 5000 may be taken by AirPlay Receiver → the script finds the next free port automatically
  • To disable AirPlay: System Settings → General → AirDrop & Handoff → AirPlay Receiver → Off
  • Or specify a port manually: PORT=8080 bash run.sh

Linux (Ubuntu / Debian)

• Requires Python 3.8+: sudo apt install python3
• python3-venv is installed automatically if missing (requires sudo)
• If the project is on an NTFS/exFAT drive (no symlink support), the virtual environment is created in ~/.local/share/sql-query-practice-venv instead
• Browser opens automatically via xdg-open (requires a desktop environment)

Windows

• Python is installed automatically if not found (via winget or direct download from python.org)
• Virtual environment and dependencies are set up automatically
• Browser opens automatically
• Port is selected automatically starting from 5000

What's Inside

5 related tables with realistic data:

#	Table	Description
1	users	25 users from different cities
2	orders	40 orders
3	products	20 products
4	returns	12 returns
5	service_requests	18 support tickets

130 exercises covering:

• SELECT / WHERE / ORDER BY / LIMIT
• AND / OR / IN / NOT IN / LIKE / BETWEEN / IS NULL
• COUNT / SUM / AVG / MIN / MAX
• GROUP BY / HAVING
• JOIN / LEFT JOIN
• ROUND / COALESCE / LOWER / concatenation
• CASE WHEN
• Subqueries
• INSERT / UPDATE / DELETE
• Multi-table JOINs (3, 4, 5 tables)

Features

• Choose SQL dialect: SQLite, MySQL or PostgreSQL
• Sequential or random exercise order
• 1 to 5 tables depending on what you want to practice
• Hint system hidden behind a button
• Reveal answer on demand
• Answer checked by comparing actual query results, not strings
• DML exercises reset the data before each check

Stack

Python 3.8+ / Flask / SQLite / CodeMirror / Vanilla JS

Project Structure

sql-query-practice/
├── app.py
├── database.py
├── exercises.py
├── run.sh
├── run.bat
├── assets/
├── static/
│   ├── style.css
│   └── script.js
└── templates/
    ├── welcome.html
    ├── trainer.html
    └── complete.html