python - 如何过滤DetailView中的附加模型？

Question

class Source(models.Model):
    Name = models.CharField(max_length=150)`enter code here`
    Address = models.CharField(max_length=150)
    Office_Phone = PhoneField(blank=True, help_text='Office phone number')
    Main_Contact = models.CharField(max_length=150, blank=True, null=True)
    Contact_Email = models.EmailField(max_length=254, blank=True, null=True)
    Contact_Phone = PhoneField(blank=True, help_text='Main Contact phone number')
    Billing_Contact = models.CharField(max_length=150, blank=True, null=True)
    Billing_Email = models.EmailField(max_length=254, blank=True, null=True)
    Billing_Phone = PhoneField(blank=True, help_text='Billing Contact phone number')
    Notes = models.CharField(max_length=250, blank=True, null=True)

    def __str__(self):
        return self.Name

    def get_absolute_url(self):
        return reverse('sources-detail', kwargs={'pk': self.pk})


class Rate(models.Model):
    Source = models.ForeignKey(Source, on_delete=models.CASCADE)
    Report_Type = models.ForeignKey(ReportType, on_delete=models.CASCADE)
    Amount = models.DecimalField(max_digits=6, decimal_places=2, blank=True, null=True)

class SourceDetailView(DetailView):
    model = Source
    template_name = 'intake/source_detail.html'
    context_object_name = 'source'

    def get_context_data(self, *args, **kwargs):
        context = super(SourceDetailView, self).get_context_data(*args, **kwargs)
        context['rates'] = Rate.objects.all.filter(***not sure what to put here***)        
        return context

在模板中过滤它还是在 View 中进行过滤会更好？如果我不过滤它而只使用 Rate.objects.all()，我就能得到结果。 ，然后我在我的模板中过滤它。只是认为有更好的方法来做到这一点。

Answer 1

您可以反向获取关系:

class SourceDetailView(DetailView):
    model = Source
    template_name = 'intake/source_detail.html'
    context_object_name = 'source'

    def get_context_data(self, *args, **kwargs):
        context = super(SourceDetailView, self).get_context_data(*args, **kwargs)
        context['rates'] = self.object.rate_set.all()
        return context

话虽如此，这里在模板中进行查询没有太大区别，因为这里只有一个对象，所以不存在N+1问题。