如何将模型中的某些值与ForeignKey相关联？

Question

我有两个模型：Product和Currency。class Product(models.Model):  Currency = models.ManyToManyField(    'Currency', verbose_name=u'Currency', blank=True, null=True)class Currency(models.Model):  Name = models.CharField(u'Currency Name', max_lenght=16)  Sign = models.CharField(u'Currency Sign', max_lenght=4)将某些价值从模型。产品关联到模型。货币的最佳方法是什么？示例：model.Currency包含对象'USD'，'Euro'，'Krona'。model.Product包含与模型关联的对象“仙人掌”。货币“ USD”和“欧元”。如何设置“美元”和“欧元”的某些价格（价格）？我想这样的事情：Product.objects.get(Name='Cactus').get_price(Current.objects.get(Name='USD'))Product.objects.get(Name='Cactus').get_price(Current.objects.get(Name='Euro'))

Answer 1

class Product(models.Model):

    currencies = models.ManyToManyField('Currency', through='Pricing', blank=True, null=True)

class Currency(models.Model):

    name = models.CharField()

    sign = models.CharField()

class Pricing(models.Model):

    product = models.ForeignKey(Product)

    currency = models.ForeignKey(Currency)

    price = models.FloatField()

然后您可以使用类似

product = Product.objects.get(name='Cactus')

price = product.pricing_set.get(currency__name='USD')