SQL Average Sales Per Customer | Dataford Interview Questions

Aimpoint Digital analysts need a customer-level sales summary for a client reporting workflow. Write a PostgreSQL query that calculates the average sale amount for every identified customer.

Requirements

Group sales by customer_id and calculate the average non-null sale_amount.
Exclude sales records that do not have an identified customer, then order customers by average sale amount from highest to lowest.

Schema

sales

Column	Type	Description
sale_idPK	INT	Unique sales transaction identifier
customer_id	INT	Customer identifier associated with the sale
sale_amount	DECIMAL(10,2)	Monetary value of the sale
sale_date	DATE	Date on which the sale occurred

Your question is SQL Average Sales Per Customer. Start with the requirements and the one table in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.

Problem

Aimpoint Digital analysts need a customer-level sales summary for a client reporting workflow. Write a PostgreSQL query that calculates the average sale amount for every identified customer.

Requirements

Group sales by customer_id and calculate the average non-null sale_amount.
Exclude sales records that do not have an identified customer, then order customers by average sale amount from highest to lowest.

Schema

sales

Column	Type	Description
sale_idPK	INT	Unique sales transaction identifier
customer_id	INT	Customer identifier associated with the sale
sale_amount	DECIMAL(10,2)	Monetary value of the sale
sale_date	DATE	Date on which the sale occurred

Your question is SQL Average Sales Per Customer. Start with the requirements and the one table in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.