Write a SQL query to compare current month revenue with the previous month for each product.
Use the latest month present in sales as the current month. Revenue is calculated as quantity * unit_price; products without sales in either comparison month must still appear.
product_id ascending.product_id, product_name, current_month, previous_month, current_month_revenue, previous_month_revenue, revenue_change, and revenue_change_pct.| Column | Type | Description |
|---|---|---|
| product_idPK | INT | Unique product identifier |
| product_name | VARCHAR(100) | Product name |
| Column | Type | Description |
|---|---|---|
| sale_idPK | INT | Unique sale identifier |
| product_id | INT | Product sold |
| sale_date | DATE | Date of sale |
| quantity | INT | Units sold |
| unit_price | NUMERIC(10,2) | Price per unit |