Rolling Revenue Average

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

Domain

SQL

Difficulty

hard

Seniority

senior

Problem

Compute a 3-month rolling average of total revenue from transactions, excluding refunds (negative amounts). For each month, the average uses the current month and the two preceding months. Show year-month in YYYY-MM format and the rolling average, sorted chronologically. The first two months will not be true 3-month averages.

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