Write a query using window functions to rank healthcare providers based on their monthly booking volume within each geographic region for Zocdoc.
Use completed bookings from January and February 2025. Rows associated with a provider whose region is NULL must be ignored.
region, booking_month, provider_id, provider_name, booking_volume, and regional_rank.| Column | Type | Description |
|---|---|---|
| provider_idPK | INT | Unique healthcare provider identifier |
| provider_name | VARCHAR(100) | Provider display name |
| region | VARCHAR(50) | Geographic region for the provider |
| Column | Type | Description |
|---|---|---|
| booking_idPK | INT | Unique booking identifier |
| provider_id | INT | Referenced healthcare provider |
| booked_at | TIMESTAMP | Timestamp when the booking was created |
| status | VARCHAR(50) | Booking lifecycle status |