models.py

Question

我有一个关于一次保存三个表单的问题。前两个表单保存OK没有问题，但是当form2保存到数据库时，第三个表单必须从form2请求id。不知道这个程序的问题在哪里以及我犯错的地方。

models.py

class Product_service(models.Model):
    id = models.AutoField(primary_key=True)
    name = models.CharField(max_length=255, blank=True, null=True)
    selling_price = models.DecimalField(decimal_places=5, max_digits=255, blank=True, null=True)
    purchase_price = models.DecimalField(decimal_places=5, max_digits=255, blank=True, null=True)
    description = models.CharField(max_length=255, blank=True, null=True)
    image = models.FileField(upload_to="/", blank=True, null=True)
    product_code = models.CharField(max_length=255, blank=True, null=True)
    product_code_supplier = models.CharField(max_length=255, blank=True, null=True)
    product_code_buyer = models.CharField(max_length=255, blank=True, null=True)
    min_unit_state = models.CharField(max_length=255, blank=True, null=True)
    state = models.CharField(max_length=255, blank=True, null=True)
    vat_id = models.ForeignKey('VatRate', related_name='vat_rate')
    unit_id = models.ForeignKey('Units', related_name='unit_value')
    category_id = models.ForeignKey('Category', related_name='product_services', blank=True, null=True)

    def __str__(self):
        return self.name

此模型代表form2。

class InvoiceProdService(models.Model):
    id = models.AutoField(primary_key=True)
    invoice_id = models.ForeignKey('OutgoingInvoice', related_name='outgoing_invoice', blank=True, null=True)
    prod_serv_id = models.ForeignKey('Product_service', related_name='product_services', blank=True, null=True)
    code      = models.IntegerField(blank=True, null=True)
    prod_serv_name = models.CharField(max_length=255,blank=True, null=True)
    description = models.CharField(max_length=255,blank=True, null=True)
    rate_name   = models.CharField(max_length=255,blank=True, null=True)
    units = models.CharField(max_length=255, blank=True, null=True)
    price = models.DecimalField(decimal_places=5, max_digits=255, blank=True, null=True)
    vat   = models.DecimalField(decimal_places=5, max_digits=255, blank=True, null=True)
    current_vat = models.DecimalField(decimal_places=5, max_digits=255, blank=True, null=True)
    price_no_vat = models.DecimalField(decimal_places=5, max_digits=255, blank=True, null=True)


    def __str__(self):
        return self.id

此模型代表form3。其中两个字段与ForeignKey关联到form2。

invoice_id = models.ForeignKey('OutgoingInvoice', related_name='outgoing_invoice', blank=True, null=True)
prod_serv_id = models.ForeignKey('Product_service', related_name='product_services', blank=True, null=True)

当我尝试使用管理界面时，我可以将表单直接保存到数据库。而且效果很好。

views.py

以下是保存方法中的逻辑：

if request.method == 'POST':

        form1 = InsertNewCustomer(request.POST, prefix='form1')
        form2 = Outdrew(request.POST, prefix='form2')
        form5 = MultiplyInsertValues(request.POST, prefix='form5')

        if (form1.is_valid() and form2.is_valid() and form5.is_valid()):

            a, created = OrganizationInfo.objects.get_or_create(**form1.cleaned_data)

            if created:
                b = form2.save(commit=False)
                b.user_id = user_pk
                b.organization_id = org_id.id
                b.customer_id = a
                b.save()
                c = form5.save(commit=False)
                nesto = Product_service.objects.get(name= form5.cleaned_data['prod_serv_name'])
                c.prod_serv = nesto.id
                c.save()
                return HttpResponseRedirect('/izlazni_racuni/')
            else:
                b = form2.save(commit=False)
                organ_id = OrganizationInfo.objects.get(oib=form1.cleaned_data['oib'])
                b.user_id = user_pk
                b.organization_id = org_id.id
                b.customer_id = organ_id.id
                b.save()
                c = form5.save(commit=False)
                nesto = Product_service.objects.get(name= form5.cleaned_data['prod_serv_name'])
                c.invoice_id = b.id
                c.prod_serv_id = nesto.id
                c.save()
                return HttpResponseRedirect('/izlazni_racuni/')
        else:
            form1 = InsertNewCustomer(prefix='form1')
            form2 = Outdrew(prefix='form2')
            form5 = MultiplyInsertValues(prefix='form5')

在此之后我收到错误消息：无法分配“80”：“InvoiceProdService.invoice_id”必须是“OutgoingInvoice”实例。

问题在线：c.invoice_id = b.id

Django版本：1.7.7

不知道这个问题在哪里有问题。

Answer 1

它来自您定义字段的方式。

invoice_id = models.ForeignKey('OutgoingInvoice', related_name='outgoing_invoice', blank=True, null=True)

Django中的ForeignKey增加了一些魔力，因此您可以直接处理对象。也就是说，根据您的定义，invoice_id被假定为OutgoingInvoice的实际实例，而数字ID实际上是 invoice_id_id 。

您可能应该在模型中将invoice_id更改为invoice：

invoice = models.ForeignKey('OutgoingInvoice', related_name='outgoing_invoice', blank=True, null=True)

如果你这样做，Django会自动将_id附加到实际的数据库字段，你可以通过id或对象访问它：

c.invoice = b         # assign object
c.invoice_id = b.id   # or assign id

实际上这两行在Django中几乎相同。您可以在relation fields的文档中找到更多信息。

Django ORM一次保存多个表单

models.py

views.py

1 个答案: