mysql count by month
select year(order_date),month(order_date),count(*)
from sales
group by year(order_date),month(order_date)
order by year(order_date),month(order_date);
+------------------+-------------------+-----------+
| year(order_date) | month(order_date) | count(*) |
+------------------+-------------------+-----------+
| 2020 | 1 | 408 |
| 2020 | 2 | 320 |
| 2020 | 3 | 540 |
| ... | ... | ... |
+------------------+-------------------+-----------+