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No SQL engine required. In your spare moments — commuting, on a break, before bed — sharpen your ability to read and predict SQL through quick four-choice quizzes.
Predict query results from a table and SQL — our signature format. Great for JOIN and GROUP BY.
Step through SQL fundamentals to subqueries and set operations, chapter by chapter.
10 seconds per question. Build combos by chaining correct answers.
Streaks, accuracy, and per-chapter heatmaps show where you stand at a glance.
SQL syntax highlighting plus a monospaced font keep code easy on the eyes.
No account, fully offline. Nothing competes for your attention.
Quick answers about how to use the app and how to fix common issues.
The app intentionally does not include a SQL engine — it trains your ability to predict results in your head. To run real queries, open Settings → "Try it for real" to launch external sites such as DB Fiddle or SQLite Online.
All study data is stored only on your iPhone and is never sent to external servers. See the Privacy Policy for details.
Settings tab → "Reset learning data" wipes your answer history, progress, and achievements (this cannot be undone).
The app picks 5 questions for that day automatically — drawn from chapters where your accuracy has been low recently or that you haven't touched in a while. Finish them all to earn that day's "Query Certificate".
Standard SQL is the baseline; dialect differences for MySQL / PostgreSQL / Oracle / SQL Server / SQLite are tagged with a "DBMS tag". You can pick which DBMS to focus on in Settings.
Yes. Every feature works fully offline. Network access is only needed for external links and App Store rating prompts.