Race against the clock. Solve SQL problems under time pressure to test your speed and accuracy.
Solve 5 basic SELECT problems as fast as you can. Perfect for warming up.
5 aggregation problems. GROUP BY, HAVING, COUNT — can you beat the clock?
5 JOIN problems of increasing difficulty. Inner, left, multi-table — show your skills.
5 finance problems across different categories. Banking data, tight deadline.
5 hard problems: window functions, CTEs, correlated subqueries. Only for the brave.