SQL Quiz
Joins, aggregates, indexes, and query design — this SQL quiz checks whether you can actually query data well. Great for data and backend interview prep.
▶ Play the SQL QuizWhat you'll be tested on
- SELECT, WHERE, and JOINs
- GROUP BY and aggregates
- Indexes and performance
- Normalization basics
How it works
1. Pick your mode. Play solo to learn at your own pace, or host a room and battle friends live.
2. Answer timed questions. Fresh AI-generated questions every round — no two games are the same.
3. Climb the leaderboard. Track streaks, XP and accuracy as you master SQL.
Frequently asked questions
Does the SQL quiz include joins?
Yes — inner, outer, and self joins are core to the question set.
Is it database-specific?
It focuses on standard SQL concepts that apply across MySQL, Postgres, and others.
Is JBattle free?
Yes. Playing quizzes, hosting rooms, and challenging friends on JBattle is completely free and runs in your browser — no download needed.