Skolarli SQL tutorials are hands-on, step-by-step walkthroughs you can follow and run. Each one answers a single concrete question, shows the working code, and explains the tradeoffs.
General
Fifteen SQL interview questions for intermediate to senior data, backend, and analytics candidates, covering joins, aggregation, subqueries, and window functions, with working queries and the efficiency trade-offs interviewers listen for. Assumes familiarity with basic SELECT, WHERE, and GROUP BY.
Read tutorialGeneral
Ten practical query-writing questions covering pagination, CASE logic, date ranges, CTEs, and upserts, the everyday patterns that come up as often as joins but rarely get grouped together. Each question pairs a working query with a less scalable alternative and the trade-off between them.
Read tutorialEvery tutorial opens with a direct answer to the question in its title, then walks through the working solution step by step. Code you can copy sits in a syntax-highlighted block. Tutorials that belong to a series are ordered from beginner to advanced so you can follow a path rather than hunt for the next piece.
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For hiring & L&D teams
These tutorials are also where teams come to shape their question banks. If you're putting together coding assessments, technical screens, or a question library for hiring or training, Skolarli's assessment platform does it at scale — with proctoring and integrity built in. Tell us what you're assessing for.