Real-World SQL Case Studies

The starter case studies are completely free with no signup — full business problem, dataset, schema, and solution. Advanced studies are part of the paid challenge packs.

No account is needed to read every case study summary. A free account unlocks the interactive SQL console with instant feedback and saves your progress across devices.

Every study ships the real-world business problem, the dataset description, the full database schema with seed data, the reference SQL solution with a step-by-step explanation, and the business insight the analysis produced.

Interview questions are standalone problems for speed and accuracy drills. Case studies are end-to-end business scenarios — context, messy data, analysis, and insight — mirroring take-home assignments and analytics interviews. Do both: drill the question bank, then prove judgment on cases.

Yes — start with Beginner studies covering SELECT, JOINs, and aggregations, then progress to window functions and CTEs. If the SQL itself feels new, work through the Learn SQL Roadmap first and return here to apply it.

Studies span Retail, Fintech, SaaS, Healthcare, and more, each modeled on the analytics problems those businesses actually solve — revenue analysis, churn, fraud, funnel conversion, and operations.