25 SQL Interview Questions

Preparing for an SQL interview can feel challenging, especially when you are not sure which questions will be asked. SQL is one of the most important skills for roles like Data Analyst, Database Developer, and Backend Engineer. This guide on 25 SQL interview questions is designed to help you revise key concepts quickly and confidently.

Interviewers usually test your understanding of database basics, queries, joins, and performance-related concepts. Common questions often start with fundamentals such as What is SQL?, What is a primary key?, and What is the difference between WHERE and HAVING?. As the interview progresses, you may face slightly advanced topics like joins, subqueries, indexes, and normalization.

Practicing these 25 SQL interview questions will help you think logically and write efficient queries. Instead of memorizing answers, focus on understanding how SQL works in real-world scenarios. For example, knowing how INNER JOIN differs from LEFT JOIN becomes much easier when you relate it to actual tables like users and orders.

Whether you are a fresher attending your first interview or an experienced professional planning a job switch, revising these questions will boost your confidence. Make sure to practice queries hands-on and explain your approach clearly during interviews.