Subqueries, also known as inner queries or nested queries, are a powerful SQL feature that allows you to write complex queries by embedding one query inside another. While they can be tricky to grasp due to their structure, especially for beginners, mastering them is key to working with complex datasets.

This intermediate-level course is designed to help you master subqueries, whether you're learning them for the first time or looking for a refresher. In the first part, you'll learn the fundamentals of subqueries, including both correlated and non-correlated subqueries. If you’re already familiar with subqueries, this section serves as a solid review to brush up on your knowledge.

The remaining five parts offer extensive hands-on practice. You'll work through over 70 exercises across five different datasets:

• Orchestras dataset: Understand how subqueries can be used to analyze music groups and their performances.
• Store dataset: Practice applying subqueries to filter and analyze sales data.
• University dataset: Use subqueries to examine student enrollments, courses, and grades.
• Track running competition results dataset: Analyze race results and performance data using subqueries.
• Blog traffic dataset: Explore how subqueries can help in understanding website traffic and visitor behavior.

The datasets are based on real-world scenarios, ensuring that the exercises are both practical and applicable, helping you build skills for everyday SQL work.

To get the most out of this course, you'll need a basic understanding of the basics of SQL, including commands like SELECT, FROM, WHERE, GROUP BY, HAVING, and ORDER BY. If you don’t know them, try our course SQL Basics.

This is an interactive course—you'll write SQL queries directly in your web browser. Our platform runs and checks your queries in real-time, with no installations required, so you can jump right into practice.

You’ll receive a certificate of completion after successfully finishing the course.

Whether you're looking to learn SQL subqueries from scratch or refine your existing skills, this course provides the perfect mix of theory and practice.

What Do You Need To Take This Course?

• A web browser and an Internet connection
• Basic knowledge of SQL

Who Should Take This Course?

• SQL beginners looking to learn subqueries from the ground up.
• Intermediate SQL users who want to practice and refine their subquery skills.
• Data analysts or developers who need hands-on experience with SQL subqueries across diverse datasets.
• Anyone preparing for SQL interviews or exams that cover subqueries.