600+ SQL Interview Questions for 2025

600+ SQL Interview Questions for 2025 udemy course

Get ready for an SQL interview: 600+ Real-world SQL questions and practical answers.

Mastering SQL Developer Interviews: 600+ Real-World Questions & Answers

Course Description:

Are you preparing for an SQL Developer interview? This course is designed to help you master SQL concepts with 600+ real-world SQL interview questions and practical answers. Whether you're a beginner or an experienced professional, this course covers everything from fundamental SQL queries to advanced database concepts to help you excel in your interview.

What You’ll Learn:

          SQL Fundamentals – Joins, Subqueries, Normalization, Indexing, and Transactions
          Database Design & Optimization – Best practices for handling large datasets
          Advanced Concepts – Common Table Expressions (CTEs), Triggers, Stored Procedures
          Hands-on Practice – Real-world SQL challenges with expert solutions
          Interview Strategies – Avoid common pitfalls and showcase your SQL skills effectively

Course Highlights:

          Video lectures for revision – Quickly review key concepts before your interview
          Comprehensive Q&A discussions – 600+ real-world SQL questions with detailed explanations
          Practical Examples & Exercises – Strengthen your SQL skills with hands-on learning

Few Sample Interview Questions Covered:

Database Design & Normalization

          What is normalization?
          How do you implement normalization?
          What is denormalization?
          OLTP vs. OLAP – What's the difference?
          Explain the 1st, 2nd, and 3rd Normal Forms.

Keys, Data Types & Indexing

          Primary Key vs. Unique Key
          Char vs. Varchar – Key Differences
          Char vs. NChar – How do they differ?
          What is the size difference between Char and NChar?
          What is an Index, and how does it speed up search operations?

Joins & Queries

          What are the different types of Indexes?
          Clustered vs. Non-Clustered Index – When to use which?
          What are Inner Joins, Left Joins, Right Joins, and Cross Joins?
          What is UNION, and how does it differ from UNION ALL?

SQL Functions & Performance Optimization

          What are Triggers, and why are they used?
          What are the types of Triggers?
          Functions vs. Stored Procedures – What's the difference?
          How do transactions work in SQL, and how do you implement them?

Subqueries & CTEs

          What is a Subquery? Can it return multiple results?
          How do Subqueries compare to Joins in terms of performance?
          What is a Common Table Expression (CTE), and why is it useful?
          Can we execute a CTE multiple times?

Finding the Nth Highest Salary & Advanced SQL Concepts

          How do you find the Nth highest salary in SQL?
          What are the different methods to achieve this using correlated queries and T-SQL?

Who This Course Is For:

          Aspiring SQL Developers & Data Analysts
          Software Engineers working with databases
          Anyone preparing for SQL job interviews

With engaging video lectures and 600+ SQL interview questions, this course will boost your confidence and help you ace your next SQL Developer interview. Enroll now and take the next step in your career!