Do I need advanced SQL to attempt this?

This problem is labeled as Intermediate. You don’t need to be an expert, only comfortable with SQL and willing to experiment. If you get stuck, the hints and solution will help you along.

Will I get hints and step-by-step explanations if I get stuck?

Yes. Every problem comes with optional hints you can reveal one at a time, plus a fully worked step-by-step solution. Hints and solutions will link to Learning Pages where you can get more information about particular concepts. You decide how much help you want while practicing.

Practice SQL Window Functions | Xorthax's Trading Post

Tables Used

orders

Column	Type
orderid	bigint
customerid	bigint
orderdate	timestamp without time zone
totalamount	double precision
status	text

Expected Output

Column
customerid
orderid
totalrevenue

1. Galactic Customer Revenue Breakdown

Track each customer's contribution to the Zlacksys 19 treasury.

Xorthax is reviewing his customer transactions across the galaxy. He wants to know the total revenue generated by each customer at his trading post on Zlacksys 19. Write a query to calculate the revenue contribution of each order, along with the total galactic revenue per customer.

Write Your Query

This problem is labeled as Intermediate. You don’t need to be an expert—just comfortable with SQL and willing to experiment. If you get stuck, the hints and solution will guide you step by step.

Yes. Every problem comes with optional hints you can reveal one at a time, plus a fully worked step-by-step solution. You decide how much help you want while practicing.

All problems on PracticeWindowFunctions.com are completely free and can be solved without creating an account. Right now there are over 80 practice problems, with new ones added regularly.

Ace the Data Science Interview

Comprehensive prep for data interviews: SQL, stats, product sense, and case studies.

(Affiliate link – as an Amazon Associate I earn from qualifying purchases.)