Question

对于两种不同类别的帐户，我有两种形式。我想根据预订的类别进行一些计算。

models.py

forms.py

    class category1(models.Model):
        user = models.OneToOneField(User, on_delete=models.CASCADE)
        name = models.CharField(max_length=100)
        contact = models.CharField(max_length=100)
        email = models.CharField(max_length=100)

        def __str__(self):
            return self.name

    class category2(models.Model):
        user = models.OneToOneField(User, on_delete=models.CASCADE)
        name = models.CharField(max_length=100)
        contact = models.CharField(max_length=100)
        email = models.CharField(max_length=100)

        def __str__(self):
            return self.name

    class booking(models.Model):
        booked_by = models.CharField(max_length=100)
        amount = models.IntegerField()
        Total = models.IntegerField()

        def save(self, *args, **kwargs):
            if self.booked_by == category1:(NEED HELP OVER HERE, what query should I use)
                self.Total = self.amount * 2
            if self.booked_by == category2:(NEED HELP OVER HERE, what query should I use)
                self.Total = self.amount * 4
            super(booking,self).save()

view.py

    class bookingform(ModelForm):
        class Meta:
            model = booking
            exclude = ('booked_by','Total')

如果按类别1进行预订，则进行一些计算。如果按类别2进行预订，请进行一些计算。

Answer 1

如果我们假设User是标准的django用户模型，则可以这样做：

def save(self, *args, **kwargs):
    if category1.objects.filter(user__username=self.booked_by).exists():
        self.Total = self.amount * 2
    if category2.objects.filter(user__username=self.booked_by).exists()
        self.Total = self.amount * 4
    super(booking,self).save()

但是最好将booked_by定义为User的外键。在这种情况下，您将获得数据库一致性：

class booking(models.Model):
    booked_by = models.ForeignKey(User, on_delete=models.CASCADE)
    amount = models.IntegerField()
    Total = models.IntegerField()

    def save(self, *args, **kwargs):
        if category1.objects.filter(user=self.booked_by).exists():
            self.Total = self.amount * 2
        if category2.objects.filter(user=self.booked_by).exists()
            self.Total = self.amount * 4
        super(booking,self).save()


class bookings_create(LoginRequiredMixin,CreateView):
    login_url = 'Mel:user_login'
    form_class = bookingform
    template_name = 'Mel/bookings_form.html'

    def form_valid(self, form):
        form.instance.booked_by = User.objects.get(username=self.request.user)
        return super(bookings_create, self).form_valid(form)

Answer 2

两个类别都具有相同的字段。应该有一个Category模型并使用Foreign Key关系。

如何根据Django模型名称实例进行计算？

2 个答案: