How it works
Read a little, then prove it
No video to watch. Every lesson and question here is something you do, graded the moment you submit.
Read the brief
Every question is a realistic scenario — a Grab ops dashboard, a Shopee orders table, a Maybank loan book — not generic trivia. One clear ask, not a spec.
Write the query
A real Postgres compiled to WebAssembly runs entirely in your browser tab. No account, no install, no setup screen between you and the editor.
Get graded instantly
Hit run and your result set is compared against the answer the second you submit. A near miss shows exactly which rows are missing or extra, not just pass/fail.
Get unstuck without the answer
Stuck? Progressive hints — sub-problem, then skeleton SQL, then the trap — before you ever see the solution. Signed in, an AI coach reviews your specific query.
Try it now
Wallets with a healthy balance
No sign-in needed to try this one — sign in only when you want your progress saved.