Whether you're a fresh graduate, a data analyst, or a software developer, SQL is one of the most critical skills to master for database-related roles. This guide will walk you through 30 essential SQL interview questions and answers, grouped by difficulty level: Beginner , Intermediate , and Advanced . Beginner SQL Interview Questions with Answers These questions focus on basic SQL syntax, concepts, and simple queries. What is SQL and why is it used? Answer: SQL (Structured Query Language) is used to interact with relational databases. It allows users to query, insert, update, and delete data. What are the different types of SQL statements? Answer: DDL (Data Definition Language): CREATE , ALTER , DROP DML (Data Manipulation Language): SELECT , INSERT , UPDATE , DELETE DCL (Data Control Language): GRANT , REVOKE TCL (Transaction Control Language): COMMIT , ROLLBACK , SAVEPOINT What is the difference between WHERE and HAVING ? Answer: WHERE filters...