如何在Django查询集中混合使用Sum和arithmetic

Question

我在我的代码中有这样的代码：

   forcasting_order = ProductLine.objects.values('product_name', 'product_id')\                                                                                         
       .filter(delivery_date__date__in=ref_days, order_date__date=Func(F('delivery_date'),function="date"))\                                                            
       .annotate(quantity_to_order=Sum('quantity'))\                                                                                                                    
       .order_by('product_id')                                                                                                                                          


   for x in forcasting_order:                                                                                                                                           
       x['quantity_to_order'] = round(x['quantity_to_order'] / Command.avg_on_x_week)        

有没有办法在查询中用Sum('quantity')除以一个常量整数(这里是Command.avg_on_x_week)？

Answer 1

尝试如下所示：

from django.db.models import Value

.annotate(quantity_to_order=Sum('quantity') / Value(Command.avg_on_x_week))