Add latest_months_on.
Refactor the admin/statistics/products using Presenter.
Import statistics modules to sales_order and sales_order_item models.
sum_by can accept 1+ sum_field_names.
Add best_selling to sales_order_item model.
Be able to customize the COUNT field in count_by.
Send opts to sum_by in sum_by_date_trunc.
Fix the bug in latest_months_on method.
When the field belongs to a join table, it will raise an error.
Add sum_ext_price_by_latest_months to sales_order_item model.
Extract some codes to a private method.
Add admin/statistics/sales_orders_presenter.