Practice SQL on Real Databases
The LeetCode for SQL & Data Engineering. Solve problems on production-style schemas, debug data issues, and prep for interviews — all with real SQL execution.
SELECT c.name, COUNT(o.id) AS total_orders
FROM customers c
JOIN orders o ON c.id = o.customer_id
GROUP BY c.name
HAVING COUNT(o.id) > 5;412
Problems
3
Industry Datasets
23
Tables
Real
SQL Execution
Everything you need to master SQL
A complete platform built for learning by doing, not just reading.
Practice Arena
400+ problems across 6 difficulty levels with real SQL execution and instant feedback
Data Debugging
Find duplicates, NULL bugs, wrong joins — skills no other platform teaches
Query Analyzer
Step through SQL execution visually and understand every clause
Documentation
Comprehensive SQL reference with real examples and practice links
Interview Prep
97 curated problems from FAANG, Big Tech, and FinTech interviews
Challenge Mode
Timed challenges with difficulty selection and bonus XP rewards
DB Design & Optimization
Learn normalization, ER modeling, and query optimization techniques
Leaderboard
Compete with other SQL practitioners and track your ranking
6 levels of mastery
Progress from basics to advanced topics at your own pace.
Level 1
Fundamentals
70
problems
Level 2
Aggregations
65
problems
Level 3
Joins
70
problems
Level 4
Subqueries
55
problems
Level 5
Window Functions
50
problems
Level 6
Advanced
102
problems
Real-world datasets
Practice on production-style schemas with realistic data.
E-Commerce
Orders, products, customers, reviews — a full retail data model
Finance
Transactions, accounts, loans, cards — real banking data
Healthcare
Patients, doctors, prescriptions, billing — clinical data at scale
Ready to master SQL?
Stop reading tutorials. Start writing real queries against real databases. Free to get started.