Question 1

Does SQL Quest explain why my query is wrong?

Accepted Answer

Yes — and this is what separates SQL Quest from every other SQL practice site. When you submit a wrong query, SQL Quest runs a structured diagnosis and explains the specific gap: wrong column count, different sort order, NULL handling issue, off-by-one cell values, SQL syntax error translated to plain English. Every other SQL practice site (DataLemur, LeetCode, HackerRank, StrataScratch) just says 'incorrect, try again' — SQL Quest tells you exactly what went wrong and gives actionable hints.

Question 2

Does SQL Quest remember my progress between sessions?

Accepted Answer

Yes. When you return after 2+ hours away, SQL Quest greets you with a Welcome Back card showing your last-session stats (attempted, solved, top focus skill), what specific challenges you got stuck on, and a one-click resume button to pick up where you left off. The AI Coach also reads this history so hints can reference past struggles: 'Last time you hit a wall with CASE WHEN placement — same root cause here.' Real tutor behavior.

Question 3

How is the AI tutor different from other SQL practice site AIs?

Accepted Answer

Most SQL site AIs run on GPT-3.5 with a basic system prompt. SQL Quest's Coach runs on Claude (Anthropic) with contextual memory: it reads your session recap, current wrong-answer diagnosis, whether you've revealed the structure skeleton, and the specific challenge you're on. So instead of generic 'this is a GROUP BY problem' hints, you get 'you're making the same NULL-handling mistake from last session — try COALESCE here.' It feels like a tutor who remembers you.

Question 4

I already took a SQL course on Udemy or Coursera — is this repetitive?

Accepted Answer

No. SQL Quest's adaptive coach reads your skill radar before recommending anything. If you already know SELECT basics, it skips the SELECT lesson and routes you straight to your weak spots. The whole point is to target what your course didn't make stick.

Question 5

How is SQL Quest different from a video course?

Accepted Answer

Videos show you SQL. SQL Quest makes you produce queries cold. Mastery checks require fresh solves on challenges you haven't seen before. Retrieval checks schedule a spaced checkpoint a day after each lesson so concepts transfer to long-term memory — something no video format can do.

Question 6

How is SQL Quest different from LeetCode for SQL?

Accepted Answer

LeetCode is a problem bank. SQL Quest is an adaptive tutor. It tells you which problem to solve next and why, based on your skill radar across 10 canonical SQL skills. You never stare at a problem list wondering where to start.

Question 7

What does the adaptive coach do?

Accepted Answer

Pick a goal (SQL Fundamentals, FAANG Interview Prep, and more coming). The coach walks a hand-crafted curriculum, skipping any step your radar already shows mastery on, and gates advancement with mastery checks and spaced retrieval checkpoints. One click launches the exact next thing to do.

Question 8

Will this help me pass a FAANG SQL interview?

Accepted Answer

Yes — FAANG interview prep is one of the goal tracks. The question patterns that Meta, Google, Amazon, Apple, and Netflix actually ask are covered, along with a mock interview mode with timed scoring. But the platform is not only interview prep — it's adaptive SQL mastery more broadly.

Question 9

Can I practice SQL with industry-specific data instead of generic ecommerce or movies?

Accepted Answer

Yes — three industry tracks ship with real public datasets, not synthetic scenarios. (1) Banking & Finance: 20 challenges on FDIC BankFind data (200 US banks including JPMorgan, BoA, Citi). Practice tier1 capital ratios, NPL detection, branch geographic analysis, fraud patterns on actual regulator data. (2) Real Estate: 20 challenges on NYC OpenData (PLUTO building footprints, ACRIS property deeds, DOB construction permits). Practice neighborhood analytics, transaction patterns, building age vs assessed value. (3) Manufacturing: 20 challenges on UCI AI4I 2020 predictive maintenance dataset (industry-standard ML benchmark used by Siemens, GE, Honeywell). Sensor analytics, failure mode detection, quality control. Filter via URL: sqlquest.app/app.html?sector=finans (or gayrimenkul, uretim) — or pick a sector card from the Practice tab.

Question 10

Is SQL Quest free to use?

Accepted Answer

Yes. The Coach, skill radar, weekly report, around 120 Easy and Medium challenges, and 10 AI tutor calls per day are free forever, no card. Every signup also starts on a 7-day Pro trial that unlocks Hard challenges, the full mock-interview bank, unlimited AI tutor, and all sector tracks. After 7 days you drop back to Free automatically unless you upgrade.

Question 11

Do I need to install anything?

Accepted Answer

No. SQL Quest runs entirely in your browser using WebAssembly-powered SQLite. Works on Chrome, Firefox, Safari, and Edge. No downloads, no configuration.

Question 12

Does SQL Quest support Turkish or other languages?

Accepted Answer

Yes — Turkish is live. The AI Coach speaks Turkish natively (powered by Claude), so it auto-responds in Turkish when you write Turkish. There is also a dedicated Turkish landing at /turkce-sql-ogren/. We prioritize localization by where users actually come from (Türkiye is 43% of current traffic). Other languages will follow.

Question 13

What is the refund policy on Pro?

Accepted Answer

Reasonable. 7-day full refund on Monthly and Annual plans. 14-day refund on the Lifetime plan if you've completed fewer than 10 challenges. Email support@sqlquest.app or see /refund.html for full terms.

Feature	SQL Quest	DataLemur	StrataScratch	HackerRank	LeetCode DB	SQLBolt
Explains why your query is wrong	✓	—	—	—	—	—
Remembers your last session	✓	—	—	—	—	—
AI Coach with contextual memory	✓ Claude	—	—	—	—	—
Show Structure progressive hints	✓	—	—	—	—	—
Adaptive Coach (picks your next)	✓	—	—	—	—	—
Company-tagged challenges	✓ 13 cos	✓ ~6	✓	partial	—	—
Browser-only (no install)	✓	✓	✓	✓	✓	✓
Substantial free tier	✓	partial	paywall	✓	✓	✓

You finished the course.
Now actually write the queries.

Your coach reads your radar, then picks the next step

Practice on real industry data

The SQL questions FAANG actually asks

The tutor features no other SQL site has

Every feature is built on what real users tell me

Wrong-answer diagnostics

Show Structure hints

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Every signup starts on 7 days of Pro

The course taught you syntax.
The Coach makes you fluent.

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You finished the course.Now actually write the queries.