Calculate the total value of sales and the number of unique paying customers, grouped and sorted in descending order by payment type.
Use the sales and customers tables, including only valid paid sales associated with a customer.
payment_type, total_sales_value, and unique_paying_customerstotal_sales_value descending, with NULL payment types last and payment type ascending as the tie-breaker| Column | Type | Description |
|---|---|---|
| sale_idPK | INT | Unique sale identifier |
| customer_id | INT | Customer associated with the sale |
| payment_type | VARCHAR(30) | Payment method used for the sale |
| sale_value | NUMERIC(12,2) | Value of the sale |
| sale_status | VARCHAR(20) | Sale processing status |
| Column | Type | Description |
|---|---|---|
| customer_idPK | INT | Unique customer identifier |
| customer_name | VARCHAR(100) | Customer display name |
| customer_region | VARCHAR(40) | Customer service region |