SQLGym

Keep your SQL skills sharp, wherever you are. SQLGym is a focused practice environment for people who already know SQL and want to solve problems on their iPhone.

Write real PostgreSQL queries against original fictional datasets. Run your query, compare your output, fix mistakes, and move to the next problem.

• Ten original problems across easy, medium, and hard difficulties. • Practice joins, aggregations, CTEs, subqueries, dates, and window functions. • A native SQL editor with a keyboard toolbar and schema-aware suggestions. • Inspect table schemas, sample data, and expected output as you work. • Review concise solutions after solving a problem or choosing to give up. • Track solved problems, attempts, first-attempt accuracy, and daily streaks. • Practice offline. No account or subscription required.

Queries run on your iPhone. Your progress stays on that device and does not sync across devices.

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