这是我的models.py
class Customer(models.Model):
def __unicode__(self):
return self.name
name = models.CharField(max_length=200)
type = models.ForeignKey(Customer_Type)
active = models.BooleanField(default=True)
class Sale(models.Model):
def __unicode__(self):
return "Sale %s (%i)" % (self.type, self.id)
customer = models.ForeignKey(Customer)
total = models.DecimalField(max_digits=15, decimal_places=3)
class Unitary_Sale(models.Model):
book = models.ForeignKey(Book)
quantity = models.IntegerField()
unit_price = models.DecimalField(max_digits=15, decimal_places=3)
sale = models.ForeignKey(Sale)
Views.py
def get_filter_result(self, customer_type='' volume_sale=''):
qdict = {}
if customer_type != '':
qdict['type__name'] = customer_type
qdict['active']=True
#WHAT I AM GOING TO DO NEXT
*** if volume_sale != '':
pass # This point I am asking :)
#IT RETURN CUSTOMERS BASE ON PARAMS.
queryset = Customer.objects.filter(**qdict)
*** volume_sale是:
units=Unitary_Sale.objects.all()
>>> units=Unitary_Sale.objects.all()
>>> for unit in units:
... print unit.sale.customer
... print unit.book,unit.sale.total
...
Sok nara
Khmer Empire (H001) 38.4
Sok nara
killing field (H001) 16
San ta
khmer krom (H001) 20
San ta
Khmer Empire (H001) 20
>>>
{<Customer: Sok nara>: Decimal("56.4"), <Customer: san ta>: Decimal("40")}
Decimal("56.4") , Decimal("40") this is the volume_sale
我无法找到从差异对象制作过滤器的方法,就像我的情况一样。 如果这里的每个人都帮忙解决这个问题会很棒吗?感谢。
答案 0 :(得分:2)
很酷,这实际上很容易实现。我使用了记录here和here的 Django将为您处理数据库连接。它会将这个额外字段放入模型的每个实例中,您可以在模板或视图中过滤,order_by和访问。from django.db.models import Sum
query = Customer.objects.all().annotate(volume_sale = Sum('Sale__total'))
query.filter(volume_sale < 12.0) #return all customers that have purchased less than 12.0
query[0].volume_sale #you can even get it on the Customer objects given back