SQL Practice - SQL Practice Online

SQL Practice

Select All Patients

Retrieve all columns from the patients table use limit 1.
Easy
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Query Result

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Entity Relationship Diagram

Database Schema Diagram

Frequently Asked Questions

Everything about SQL Practice

Is SQL Practice completely free?
Yes — 100% free. No sign-up, no credit card. Open the editor and start writing SQL instantly.
What SQL dialect does the compiler use?
SQLite for most sets (covers SELECT, JOINs, CTEs, window functions). The Hospital dataset also supports PostgreSQL.
Are these real interview questions?
Yes — curated from real interview rounds at TCS, Infosys, and Deloitte (2026). Ranges from Easy basics to Hard window functions & CTEs.
How does the auto-grader work?
Your query output is compared with the expected result. A green ✓ means correct — plus you always get the reference SQL solution.
Can I try different schemas?
Yes! Use the schema selector in the header or switch to Playground mode to explore Hospital, E-Commerce, Employees and more.
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