Write a query to find the top 10 merchants by transaction volume.
Use the available merchant and transaction records. Treat transaction volume as the count of transaction records associated with each merchant.
merchant_id, merchant_name, and transaction_volume.| Column | Type | Description |
|---|---|---|
| merchant_idPK | INT | Unique merchant identifier |
| merchant_name | VARCHAR(150) | Merchant display name |
| Column | Type | Description |
|---|---|---|
| transaction_idPK | INT | Unique transaction identifier |
| merchant_id | INT | Merchant associated with the transaction |