Average Sales Per Month | Dataford Interview Questions

Closer Consulting wants a monthly view of sales performance. Write a PostgreSQL query that calculates the average non-null sale amount for each calendar month in the sales table.

Requirements

Group sales by calendar month using the sale date.
Return the month and average sale amount, rounded to two decimal places, ordered chronologically.

AVG should ignore rows where sale_amount is NULL.

Schema

sales

Column	Type	Description
sale_idPK	INT	Unique identifier for the sale
sale_date	DATE	Date on which the sale occurred
sale_amount	DECIMAL(10,2)	Monetary value of the sale

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