SQL Ranking by Weekly Sales Growth | Dataford Interview Questions

Your question is SQL Ranking by Weekly Sales Growth. Start with the requirements and the two tables on the right.

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Problem

Domino's Operations leadership wants to identify stores with the strongest week-over-week sales improvement. Write a PostgreSQL query using the stores and weekly_store_sales tables.

Calculate growth from the week beginning 2025-01-27 to the week beginning 2025-02-03.

Requirements

Aggregate sales for each store in both weeks and exclude stores missing either week's sales.
Calculate each store's percentage sales growth, rounded to two decimal places.
Rank qualifying stores across all regions by growth, with the highest growth ranked first.
Include the average growth for the store's region and the difference between the store's growth and that regional average.

Schema

stores

Column	Type	Description
store_idPK	INTEGER	Unique Domino's store identifier
store_name	VARCHAR(100)	Store display name
region	VARCHAR(50)	Operations region

weekly_store_sales

Column	Type	Description
sales_idPK	INTEGER	Unique weekly sales record
store_id	INTEGER	Store associated with the sales record
week_start	DATE	First day of the sales week
sales_amount	NUMERIC(12,2)	Total store sales for the week