ValueError:无法分配“”26 Balkanskaya Street“”："paidparking.adress“必须是"Parking”实例

Question

我有一台paidparking模型

 class paidparking(models.Model):
        adress = models.ForeignKey(Parking, on_delete=models.SET_NULL, null=True)
        carnumber = models.CharField(max_length=150)
        amountoftime = models.IntegerField()
        price = models.FloatField()
        telephone = models.CharField(max_length=20)
        email = models.EmailField(,null=True,blank=True )
        datetimepaidparking = models.DateTimeField(auto_now_add=True)
        expirationdate = models.DateField(null=True)
        expirationtime = models.TimeField(null=True)
        enddateandtime = models.DateTimeField(null=True,blank=True)

模型停车：

class Parking(models.Model):
    adress = models.CharField(max_length=150)
    starttime = models.TimeField(auto_now=False, auto_now_add=False,null=True)
    endtime = models.TimeField(auto_now=False, auto_now_add=False,null=True)
    minimaltimeforpayment = models.CharField(max_length=50)
    price = models.IntegerField()
    numberofavailableseats = models.IntegerField(default=0)
    tickets = models.ManyToManyField('tickets', blank=True)

我在网站上有一个页面，其中有一个表单。通过此表单，我将数据保存到模型中

class paidparkingForm(forms.ModelForm):
  class Meta:
      model = paidparking
      fields = ['adress','carnumber','amountoftime', 'price', 'email','telephone','expirationdate','expirationtime','enddateandtime']
      widgets = {
          'adress': forms.Select(attrs={"class": "form-control form", "id": "exampleFormControlSelect1"}),
          'carnumber': forms.TextInput(attrs={"class": "form-control form-control-lg form"}),
          'amountoftime': forms.NumberInput(attrs={"class": "number form-control form-control-lg form", "disabled": 1}),
          'price': forms.NumberInput(attrs={"class": "form-control form-control-lg form", "readonly": 0}),
          'email': forms.EmailInput(attrs={"class": "form-control form-control-lg form"}),
          'telephone': forms.TextInput(attrs={"class": "form-control form-control-lg form"}),
          'expirationdate': forms.DateInput(attrs={"type": "date","class": "form form-control form-control-lg", "disabled": 1}),
          'expirationtime': forms.TimeInput(attrs={"type": "time", "class": "form form-control form-control-lg", "disabled": 1}),
          'enddateandtime':  forms.TextInput(attrs={"class": "form form-control form-control-lg", "readonly": 0}),
      }

如何将数据直接从函数保存到模型？

我这样做

def save_payment_parking(request):
    adress = request.GET["adress"]
    carnumber = request.GET["car_number"]
    amountoftime = request.GET["amount_of_time"]
    price = request.GET["price"]
    telephone = request.GET["telephone"]
    expirationdate = request.GET["date_time_paid_parking"]
    expirationtime = request.GET["expiration_time"]
    enddateandtime = request.GET["end_date_and_time"]
    save_payment_parking = paidparking
    save_payment_parking(adress=adress
                         ,carnumber=carnumber,amountoftime=amountoftime,price=price,telephone=telephone,expirationdate=expirationdate,expirationtime=expirationtime,enddateandtime=enddateandtime).save()

但是我得到了一个错误

ValueError: Cannot assign "'26 Balkanskaya Street'": "paidparking.adress" must be a "Parking" instance.

我在Parking adress字段的adress字段中插入了一个密钥。如何将我的行插入到地址字段中？停车模型中的地址字段具有我的行的值。也许您需要以某种方式确定记录的id，其中我的字符串等于停车模型的adress字段中的值，并插入此id。

Answer 1

在创建paidparking之前，您是否尝试创建Parking

您有一个指向不存在的对象的外键，并且正在尝试将该对象设置为字符串。

def save_payment_parking(request):
    adress = request.GET["adress"]
    carnumber = request.GET["car_number"]
    amountoftime = request.GET["amount_of_time"]
    price = request.GET["price"]
    telephone = request.GET["telephone"]
    expirationdate = request.GET["date_time_paid_parking"]
    expirationtime = request.GET["expiration_time"]
    enddateandtime = request.GET["end_date_and_time"]
    parking = Parking.objects.get_or_create(address=address)[0] # << or something
    save_payment_parking = paidparking
    save_payment_parking(adress=parking,carnumber=carnumber,amountoftime=amountoftime,price=price,telephone=telephone,expirationdate=expirationdate,expirationtime=expirationtime,enddateandtime=enddateandtime).save()

编辑-我添加了objects。检查docs