151. Deep dive into window functions. Part 1

IMO window functions are the most advanced part of SQL. It’s such a complex though powerful construct. Window functions are the last milestone on your way to become an advanced SQL user. The rest is practice, practice and more practice 🚀

Let’s take a look at the query from the last lesson. It adds numbers to users’ accounts so we can get the first account (or a signup account) of a user:

SELECT *, ROW_NUMBER() OVER (PARTITION BY user_id ORDER BY created_at ASC) AS account_number FROM accounts ORDER BY user_id ASC, created_at ASC 

ROW_NUMBER()

...

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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. 🚀

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-- Type your query here, for example this one -- lists all records from users table: SELECT * FROM users
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