A easy SQL interview practice problem on DataDriven. Write and execute real sql code with instant grading.

Domain

SQL

Difficulty

easy

Seniority

L3

Problem

For promo campaigns (campaign names containing 'promo'), compute the cost-per-acquisition by year: total notifications divided by total opens. Show the campaign, year, and the resulting ratio.

Summary

The campaign ran. What did each customer cost?

Practice This Problem

Solve this SQL problem with real code execution. DataDriven runs your SQL queries against a real database and grades it automatically.