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// master the syntax · conquer the interview
Learn SQL online free — 27 beginner-friendly topics from first SELECT to expert analytics, with syntax, examples, and interview tips.
// conquer the interview
Learn SQL online free — 27 beginner-friendly topics from first SELECT to expert analytics, with syntax, examples, and interview tips.
Start Learning Practice playground// SELECT YOUR CURRICULUM
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Tick the circle next to any topic — or open one and hit “Mark as complete”.
—Always clarify the question first — ask about edge cases, expected output, and scale.
Think aloud during the interview. Explain your approach before writing code.
Start with the simplest query that works, then refactor for performance.
Always check for NULLs, ties, empty tables, and duplicates in your answer.
Use EXPLAIN to show you think about performance, not just correctness.
Know SQL execution order cold: FROM → JOIN → WHERE → GROUP BY → HAVING → SELECT → ORDER BY.
// FAQ
Most beginners reach working fluency in 2–4 weeks at 30–60 minutes a day: week one for SELECT, WHERE, and JOINs, then aggregations, subqueries, and window functions. This 27-topic roadmap is ordered exactly in that progression, so follow it top to bottom.
No — SQL is one of the easiest programming languages to learn because queries read almost like English sentences. Start with SELECT and filtering, practice each topic's examples, and use the hints when you get stuck. No prior coding experience is needed.
Yes. The complete 27-topic roadmap — every explanation, syntax reference, example, and interview tip — is free with no signup. Printable cheat sheets and the SQL practice playground are free too.
Start with topic 1 and move down the roadmap in order: SELECT first, then WHERE filtering, ORDER BY, and JOINs before touching aggregations or subqueries. Each topic lists its level and duration — Beginner topics take 10–15 minutes each.
Do both: follow this roadmap for structured learning, then reinforce each topic by playing the story-driven SQL puzzle games, where chapters apply the same skills (JOINs, CTEs, window functions) inside a story. Play first if you learn best by doing.
Once you finish the Advanced topics, drill the SQL interview question bank: 90+ real interview problems with schemas, hints, and instant feedback in the browser. Finish each roadmap topic's interview tips first — they flag exactly what interviewers probe.