32. Subqueries in SQL

We’ve learned so much already and it’s time to level up 📈 🚀 In this lesson we’ll learn one of the most powerful SQL concepts and one of the pillars of analytics – subqueries.

You already see that our queries are growing and becoming more and more complex (later in the course we’ll write 50 line long queries and even more). To handle this complexity it’s a very good approach to split a big query into subqueries. You may have heard of the expression “Eat an elephant: one bite at a time”, subqueries represent this principle in SQL.

Subquery example

So...

“well worth the money”
Sign up and check out 36 free lessons and exercises.

Anatoli Makarevich, author of SQL Habit About SQL Habit

Hi, it’s Anatoli, the author of SQL Habit. 👋

SQL Habit is a course (or, as some of the students say, “business simulator”). It’s based on a story of a fictional startup called Bindle. You’ll play a role of their Data Analyst 📊 and solve real-life challenges from Business, Marketing, and Product Management.

SQL Habit course is made of bite-sized lessons (you’re looking at one atm) and exercises. They always have a real-life setting and detailed explanations. You can immediately apply everything you’ve learned at work. 🚀

“well worth the money”

Fluent in SQL in a month

Master Data Analysis with SQL with real life examples from Product Management, Marketing, Finance and more.
-- Type your query here, for example this one -- lists all records from users table: SELECT * FROM users
LIMIT 500
Loading chart... ⏳
Previous exercise: Count numbers of published books
Next lesson: Relational model of data