SQL Interview Handbook

SQL Interview Mastery 2026 is a comprehensive interview preparation resource designed for software engineers, backend developers, data engineers, and database professionals targeting top product companies. This handbook contains 100 carefully selected SQL interview questions ranging from beginner to advanced levels, along with detailed explanations and optimized solutions.

The guide covers essential topics such as SELECT queries, JOINs, GROUP BY, HAVING, subqueries, Common Table Expressions (CTEs), Window Functions, indexing, query optimization, normalization, database design, and performance tuning. Each question is crafted to help you understand not only the correct answer but also the reasoning and best practices behind it.

Whether you're preparing for interviews at Amazon, Microsoft, Google, Walmart, Adobe, Oracle, Atlassian, Flipkart, PayPal, or other leading technology companies, this resource will help you build confidence and strengthen your SQL problem-solving skills. The included real-world scenarios and interview-style challenges mirror the questions frequently asked in actual technical interviews.

By working through this handbook, you'll learn how to write efficient queries, optimize database performance, and confidently tackle complex SQL problems. Perfect for both interview preparation and day-to-day database development, this guide serves as your complete SQL interview companion.