60 lessons · in-browser SQLite · streaks

Learn SQL by writing it, not watching it.

Mastering SQL is a focused curriculum across four levels. Every lesson ships with a real dataset, an editor, and a grader — your query runs against a SQLite database right in your browser.

Four levels, end to end.

From your first SELECT to window functions and self-joins. Progress unlocks as you go.

Beginner

SELECT, WHERE, ORDER BY, LIMIT

Intermediate

JOINs, GROUP BY, aggregates, HAVING

Advanced

Subqueries, CTEs, CASE expressions

Specialized

Window functions, self-joins, performance

How a lesson works

01

Read the brief

A short, focused explanation of the concept and the dataset you'll work with.

02

Write the query

Edit SQL in the in-browser editor. Run it against a real SQLite database. Iterate freely.

03

Submit

Your query is graded against the expected result. Pass it and your progress + streak update.

Twelve lessons. One in-browser database. Real queries from day one.

Sign up takes a minute. Your account is reviewed by an admin before lessons unlock.