I have this models
class Driver(models.Model):
first_name = models.CharField(max_length=250)
last_name = models.CharField(max_length=250)
created_at = models.DateTimeField(default=NOW)
updated_at = models.DateTimeField(default=NOW)
def __str__(self):
return self.first_name
class Vehicle(models.Model):
driver_id = models.ForeignKey(Driver,on_delete=SET_NULL,unique=True,null=True, blank=True)
make = models.CharField(max_length=150)
model = models.CharField(max_length=150)
plate_number = models.CharField(max_length=10,validators = [validate_plate_numberLATIN,validate_plate_numberCYRYLLIC], unique=True)
created_at = models.DateTimeField(default=NOW)
updated_at = models.DateTimeField(default=NOW)
def __str__(self):
return self.make
I try to set foreign key in my post request into Vehicle model
@method_decorator(csrf_exempt, name='dispatch')
def post(self,request,*args, **kwargs):
body = json.loads(request.body.decode("utf-8"))
newCar = Vehicle.objects.create(driver_id=body['driver_id'],make=body['make'],model=body['model'],plate_number=body['plate_number'])
data = json.loads(serializers.serialize('json',[newCar]))
return JsonResponse({'success':data})
And get this error
ValueError: Cannot assign "1": "Vehicle.driver_id" must be a "Driver" instance.
How to get rid off this error? How I can create an instance of Driver and 'post' an id?
The raw value of a ForeignKey can be accessed by appending "_id" to the field name, this can also be used to create an instance using the raw value
Vehicle.objects.create(driver_id_id=body['driver_id'], ...)
You can do it in 2 ways
If you need the driver instance in somewhere in the code you can use this
driver_instance = Driver.objects.get(pk=body['driver_id'])
Vehicle.objects.create(driver_id=driver_instance,..)
Vehicle.objects.create(driver_id_id=body['driver_id'], ...)