Hold a data-analyst job. Answer your inbox in SQL.

It's a job, not a problem set.

Requests arrive the way they do at work — a sentence or two from someone who doesn't know or care how the database is laid out. You read it, work out what they actually need, and write the SELECT. It runs against the company's real tables and your result is checked column by column, order-independent. Some come in urgent, on a countdown. Keep your reputation up and you level up; let it slide and you get let go and pick a new job.

SELECT b.branch_name, COUNT(*) AS new_accounts
FROM   bank_accounts a
JOIN   bank_branches b ON b.branch_id = a.branch_id
WHERE  a.account_type = 'checking'
  AND  a.opened_date >= CURRENT_DATE - INTERVAL 30 DAY
GROUP BY b.branch_name
ORDER BY new_accounts DESC
LIMIT  10;

Not sure what they mean by “new”? Reply to the colleague and ask — or, in the full simulator, open an intake call and ask as many questions as you want before you answer.

Closer to the actual job.

Most SQL practice hands you a prompt, the exact columns to return, and a schema diagram. Real analyst work gives you none of that — and neither does this.

Eight companies to work for.

Each is a full database of its own. Switch jobs any time — your level carries over.

The simulator is the teacher.

Lessons that come from your mistakes.

You don't pick lessons off a shelf. When the simulator sees you keep missing a skill, it writes one — against the same database you're working in, so the examples use tables you already know.

• A plain-language explanation of the skill, framed around your current job's data.
• One fully worked example query, walked through a line at a time.
• A Tables & fields browser showing exactly the tables the exercises use — click a name to drop it into the editor.
• One to three graded exercises, escalating in difficulty, checked the same way the simulator checks your replies.
• Clear them all and your mastery score on that skill jumps.

Fumble a join inside a grouping lesson? That still counts against joins. Every query you write anywhere is scored on every skill it touches.

Every core SQL skill, in context.

Not a syllabus you march through — the simulator draws from these as the requests demand, and leans harder on whatever you're weakest at.

A scorecard for every SQL skill.

Your workspace keeps a 0–100 mastery score per skill, updated on every graded reply. It's how the simulator decides what to throw at you next and what to teach — and it's the clearest read you'll get on where you actually stand.

Reputation and level ride alongside it: three clean answers and the requests get harder; a bad run and you drop a level, or get let go and pick a new job.

Everything else in the lab.

If SQL is the thing between you and the job.

Free SQL placement test.

Sixteen questions against a real retail database — no account, no payment. Score 75% or better and claim a verifiable SQL Foundations certificate you can hand an employer. Below that, you'll see exactly which skills to work on, and if you join your measured levels carry straight into your account — you don't start over.

Before you join.

One membership. All of it.