TableNotFound
Visualizers & Guides
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System Design ctrlz How ctrlz works
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Data Engineering Road Map DE Road Map
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Data Layers DataLayers
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ROW_NUMBER vs RANK vs DENSE_RANK Window functions explained
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IN vs EXISTS vs JOIN The NOT IN NULL trap explained
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LEFT JOIN vs INNER JOIN The WHERE clause trap explained
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COUNT(*) vs COUNT(column) The NULL trap explained
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UNION vs UNION ALL The silent row drop explained
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BETWEEN with Timestamps The missing last day explained
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WHERE vs HAVING Why aggregates can't go in WHERE
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NULLIF Explained Sentinel values and division by zero
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Numbers Stored as TEXT Why '10' sorts before '2'
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GROUP BY vs Window Functions The aggregate that ate your rows
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Gaps and Islands Finding streaks without a loop
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CAST's Silent Truncation Why bad TEXT quietly becomes 0 instead of an error
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About TableNotFound

Last updated: July 21, 2026

TableNotFound is a free tool for practicing SQL against real-world business scenarios modeled on companies like Flipkart, Uber, Netflix, Snapchat, Tinder, Myntra, and YouTube.

Every query runs entirely in your browser using SQLite compiled to WebAssembly — there's no backend, no account, and nothing you type is sent to a server. Close the tab and it's gone; open it again and start fresh.

Why it exists

Most SQL practice is disconnected from why the query matters. TableNotFound frames every question as a short business story first — a supplier pricing question at Flipkart, a driver earnings question at Uber — so you're solving a problem, not just matching syntax to a pattern.

About the company scenarios

Company names are used for scenario flavor only. These questions may or may not reflect anything actually asked at the named companies, and TableNotFound is not affiliated with, endorsed by, or sponsored by any of them.

Who's behind this

TableNotFound is built and maintained by Gowtham SB. You can find more of my work at linkedin.com/in/sbgowtham.

Found a bug, have feedback, or want to suggest a company scenario? Get in touch.

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