Given the table below, called 'orders', write code to show the average revenue by month by channel:
| order_id | channel | date | month | revenue |
|---|---|---|---|---|
| 1 | online | 2018-09-01 | 09 | 100 |
| 2 | online | 2018-09-03 | 09 | 125 |
| 3 | in_store | 2018-10-11 | 10 | 200 |
| 4 | in_store | 2018-08-21 | 08 | 80 |
| 5 | online | 2018-08-13 | 08 | 200 |
Your result should return the following in a structured table:
Month | Channel | Avg. Revenue