A free SQL course that makes you do the job
Two full beginner courses are free here: SQL from Zero, for people who have never written a query, and SQL Fundamentals, which takes you from SELECT to JOINs and subqueries. Every lesson has SQL you run and edit in your browser, and when you finish you practice on a real client — eight consulting engagements, also free. No card, nothing to install.
No card · in-browser · both beginner SQL courses and your entire first client (8 engagements) are free.
What the free course actually covers
SQL from Zero starts before the syntax: what a database is, how tables work, and your first running query within five minutes. SQL Fundamentals then builds the working toolkit one idea at a time — SELECT and FROM, filtering with WHERE, sorting, LIMIT, DISTINCT, grouping and aggregates, HAVING, JOINs, UNION, CASE, and subqueries. Eighteen lessons in total, and every one of them has runnable SQL in the page: you type, you run, you see rows come back from a real database in your browser.
The course closes with two lessons most free courses skip: how to write SQL that survives a code review, and why the same query behaves differently across databases — the dialect differences that bite people in their first job.
Then you practice on a real client, still free
Reading about JOINs is not the same as needing one because the category column lives in another table. So the free tier includes your entire first client: Northforge Industrial, eight consulting engagements that go from reading an order log on day one to reconciling two systems that disagree. A stakeholder briefs you, the data has the same traps real exports have (cancelled orders in the revenue column, dates stored as text), and you are graded on the business answer — any correct query passes.
There is also a free timed SQL interview screen, if you want to know whether the skills would hold up under a clock.
Honestly free, and what is not
Free means free: no card, no trial clock, no lesson limit on the two beginner courses or the eight Northforge engagements. Your first engagement does not even need an account; a free account saves your progress and rank from the second one on.
What is paid: the advanced material. Window functions, more clients, the harder interview screens, and the deeper courses sit behind a Pro tier. The free tier is deliberately a complete beginner education, not a teaser — you can go from never having written a query to delivering a full client account without paying anything.
Frequently asked
Is this SQL course really free, or free-trial free?
Really free. Both beginner courses (SQL from Zero and SQL Fundamentals, 18 lessons) and your entire first client (eight consulting engagements) cost nothing, with no card and no time limit. Advanced courses and additional clients are part of the paid Pro tier.
Do I need to install a database?
No. A real analytical database (DuckDB) runs entirely in your browser. You write and run real SQL from the first lesson, and nothing you type leaves your machine.
I've never written a query. Is this too advanced?
It starts before the first query. SQL from Zero explains what a database even is and gets you running your first SELECT in about five minutes. Every concept after that arrives one at a time, with runnable examples.
How long does the free course take?
The two courses together are roughly four hours of lessons, and most people spread the eight client engagements over a couple of weeks. There is no schedule — everything stays available.
Do I get a certificate?
You get something better to talk about: a rank you earned (Junior toward Senior) and eight delivered engagements you can walk through out loud in an interview — real queries against realistic data, not a completion PDF.
Keep reading
Learn it by doing it.
Deliver a real analysis in your browser in the next 30 minutes — free, no setup.