- About this tool
- Four small synthetic datasets (hospital, e-commerce, movies, university) live inside
engine.js; SQLite runs in your browser through sql.js 1.10.2 (vendored in vendor/). Every checkbox, filter, grouping and sort you set is turned into one SELECT, shown in the mirror and executed. Practice mode hides the mirror and grades the SQL you write against the same result. No build, no server, no account, nothing uploaded.
- Not verified here
- The engine is SQLite. The mirror uses an Oracle-style layout and shows
LIMIT as a ROWNUM comment, but the text itself is not run against Oracle: CAST(… AS TEXT) and LIMIT are SQLite constructs. The generator covers a teaching subset (inner and left joins along fixed keys, WHERE, GROUP BY, HAVING, ORDER BY, DISTINCT, five aggregates); subqueries, self-joins and window functions are out of scope. Practice grading compares result sets, not SQL text.