As a tech company, Oracle offers a diverse range of products including databases, cloud solutions, and other software services. The company would likely be interested in understanding the average sales revenue by product category. The marketing team at Oracle wants to understand the **average sales revenue made for each product category each month.** Given a relational table called 'sales' with columns sales_id(unique identifier for the sale), product_id(unique identifier for the product), category_id(unique identifier for product category), sales_date(date of the sale), and revenue(revenue from sale), **write an SQL query that retrieves the average revenue per product category for each month.** sales **Example Input:** sales_id product_id category_id sales_date revenue -------------------------------------------------------- 1001 5001 1 06/18/2022 3500 1002 6985 2 06/18/2022 4700 1003 5001 1 07/27/2022 3700 1004 6985 2 08/25/2022 5000 1005 5000 1 06/18/2022 3000 **Example Output:** month category avg_revenue ------------------------------ 6 1 3250 6 2 4700 7 1 3700 8 2 5000 **Answer:** SELECT EXTRACT(MONTH FROM sales_date) AS month, category_id AS category, AVG(revenue) AS avg_revenue FROM sales GROUP BY 1, 2 ORDER BY 1, 2 ---