django - 查询字段值 - 返回未定义的全局名称

Question

我尝试编写查询以从列表中过滤/排除某些对象，但出现错误。

我的模型:

class Benefit(TimeStampedModel):
    DEAL = 'D'
    NODEAL = 'N'

    TYPE_CHOICES = (
        (NODEAL, 'Does not need any signed deal'),
        (DEAL, 'Needs a signed deal'),
    )

    name = models.CharField(max_length=200)
    benefit_type = models.CharField(max_length=1, choices=TYPE_CHOICES, default=DEAL)    



class Profile(models.Model):
    user = models.OneToOneField(User)
    benefits = models.ManyToManyField(Benefit, verbose_name="Used benefits", blank=True, null=True, related_name="used_benefit")

我的看法:

class ProfilePage(TemplateView):
    template_name = "profile/frontpage.html"

    def get_context_data(self, **kwargs):
            context = super(ProfileFrontpage, self).get_context_data(**kwargs)
            context['unused_benefits'] = Benefit.objects.filter(used_benefit__isnull=True).exclude(benefit_type=='N')
            context['nodeal_benefits'] = Benefit.objects.filter(benefit_type=='N')
            return context

但它不起作用。我收到此错误: global name 'benefit_type' is not defined
我不知道为什么我会收到那个错误？我认为我不需要创建模型字段的变量？

Answer 1

在过滤查询中，您不需要 ==用于比较。

将您的 View 代码更新为

context['unused_benefits'] = Benefit.objects.filter(used_benefit__isnull=True).exclude((benefit_type = 'N')
context['nodeal_benefits'] = Benefit.objects.filter(benefit_type = 'N')
# ---------------------------------------------------------------^ single =