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SQL Playground
TutorialsPlayground
SQL FormatterSQL MinifierSyntax ValidatorJSON to SQLCSV to SQLSQL to JSONER Diagram Generator
Daily ChallengeInterviewsCheat SheetBlog
Start Learning

Master SQL by
Doing It.

Forget boring lectures. SQL Boy is your interactive playground to learn, practice, and master database skills directly in your browser.

Start Free TutorialSQL Cheat Sheet
Privacy First
No Setup
Local Execution
Quick Challenge: Fix the query!
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Run the query to see results...

Everything You Need to Learn SQL

Our comprehensive platform combines interactive tutorials, powerful developer tools, and visual learning aids to help you master SQL from basics to advanced concepts.

Interactive Tutorials

Learn SQL through 15 hands-on lessons covering SELECT statements, JOINs, aggregations, subqueries, and window functions. Each lesson includes real-time validation and instant feedback to help you learn faster and retain knowledge better.

Start Learning

Visual Learning Tools

Understand complex SQL concepts with interactive visualizations. See how queries are parsed with AST views, explore execution plans, and watch animated JOIN operations. Visual learning makes difficult concepts easier to grasp and remember.

Explore Visuals

Developer Tools

Professional SQL tools for everyday development work. Format queries for readability, minify SQL for production, and validate syntax across multiple database dialects including MySQL, PostgreSQL, SQLite, and MariaDB.

Try Tools

Structured Learning Path

From your first SELECT statement to complex window functions, our curriculum guides you through every concept with interactive exercises and real-world examples.

Foundations

Master the basics: SELECT, WHERE, operators, and sorting results.

5 Lessons

Aggregations

Learn to summarize data with COUNT, SUM, GROUP BY and HAVING.

4 Lessons

Joins & Unions

Connect data from multiple tables using INNER, LEFT, and CROSS JOINs.

6 Lessons

Advanced SQL

Level up with Subqueries, CTEs, and Window Functions.

5 Lessons

plus dedicated tracks for...

Data AnalysisBackend DevelopmentData ScienceInterview Prep

Build a Habit with Daily Challenges

Consistency is key to mastery. Every day, we present a new bite-sized SQL problem based on real interview questions from top tech companies.

  • Solve real-world scenarios in under 15 minutes
  • Earn streaks and badges for consistency
  • Compare your solutions with the community
  • Track your improvement over time
Try Today's Challenge

Challenge #42

Easy

Find the Repeat Customers

Write a query to identify all customers who have placed more than 3 orders in the current month...

SELECT customer_id FROM orders
WHERE order_date >= '2025-01-01'
GROUP BY customer_id
HAVING COUNT(*) > 3;

Ace Your FAANG Interviews

Stop guessing. Practice with real-world SQL interview questions from the industry's toughest hiring bars. From Airbnb's pricing logic to Meta's engagement metrics.

🏢Real Data
📊FAANG Problems
✅Instant Feedback
🔍Expert Tips
Enter Interview Pool

Privacy-First, Cloud-Enabled

SQL Boy utilizes a unique hybrid architecture that gives you the best of both worlds: the privacy and speed of local execution, combined with the convenience of cloud synchronization.

Local Processing Engine

Your SQL queries never leave your device. We use WebAssembly (WASM) to run a full SQLite engine directly in your browser. This guarantees that your practice data and query logic remain completely private.

Seamless Progress Sync

Create an account to synchronize your learning journey. Your completed lessons, badges, and daily challenge streaks are securely stored in the cloud, allowing you to switch devices without losing your momentum.

Transparent Data Usage

We only store what's necessary to track your progress. We do not inspect, log, or store the specific SQL queries you write in the playground. Your code is yours alone.

Why Hybrid Matters

Traditional online SQL editors fall into two traps: they either send every keystroke to a server (privacy risk & latency), or they are purely local but forget who you are once you close the tab.

SQL Boy solves this. By decoupling execution from progress tracking, we ensure:

  • Zero Latency: Queries run instantly.
  • Data Safety: Upload sensible CSVs safely.
  • Continuity: Your badges follow you everywhere.

Frequently Asked Questions

Is SQL Boy really free?

Yes! The core learning experience, including all tutorials, the playground, and local practice, is 100% free. We believe quality education should be accessible to everyone.

Do I need to install anything?

No. SQL Boy runs entirely in your web browser. You don't need to install MySQL, PostgreSQL, or any other software. We use a powerful WASM-based SQLite engine that runs right in your browser tab.

Can I use my own data?

Absolutely. You can upload your own CSV or JSON files to the playground. Since processing happens locally, your private data never leaves your computer.

How is this different from LeetCode or HackerRank?

LeetCode focuses on assessment and algorithmic puzzles. SQL Boy is designed for *learning*. We provide interactive lessons, visualizations of how queries work (like animated joins), and a sandbox environment for exploration, not just pass/fail tests.

What SQL dialect do you use?

We currently use SQLite, which is the most widely deployed database engine in the world. The syntax is very similar to PostgreSQL and MySQL, so everything you learn here applies to other major databases.

Ready to Master SQL?

Join thousands of learners who have improved their SQL skills with our interactive platform. Start your journey today - it's completely free!

Begin Your SQL Journey

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