A guided sheet of every SQL pattern, optimisation trick, product metric, and business question I’ve seen across Zomato, Zepto, and Top Q-Comm, paired with the writing that explains the why.
Write real queries against real datasets, get graded on the spot, and build a streak while you get sharper. This is the tool the rest of the site builds up to.
Real PostgreSQL, in your browser
No sandbox limits, no setup. A real Postgres engine runs your query the instant you hit Run.
Graded the moment you submit
Check compares your output against the real answer and tells you exactly what passed.
Streaks and Sprint Coins
Solve daily, keep a streak, earn coins you spend on hints and full solutions.
Noob or Master mode
Practice with copy allowed, or lock it down and force yourself to actually type the query.
Not every session needs a graded exercise. Open a blank Postgres tab, build your own schema, or load a dataset and poke around, all in your browser.
Skip the setup, load real data
Pick a dataset from the dropdown and you’re querying real tables instantly, no schema to write first.
Or start from a blank tab
Create your own tables, insert your own data, and query them freely. No exercise, no grading, just SQL.
Real PostgreSQL, timed runs
The same engine that powers QueryLab. Every query is timed, with a hard stop on runaway ones.
Picks up where you left off
Your tab and dataset are saved automatically, close it and come back to exactly what you had.
Eight steps, sequenced by what actually builds on what.
Jump straight to whatever topic is blocking you.
Long-form essays that explain the why, not just the how.
Practice SQL on real datasets, right in your browser.
A free-form SQL scratchpad, no exercise required.
Cheat sheets and reference cards, ready to download.