Django REST Framework Foreign Key - cannot create object from JSON - django

Question

I have following setup
Models
class Day(models.Model):
date = models.DateField(auto_now=False, auto_now_add=False)
price = models.FloatField()
paymentMethod = models.CharField(max_length = 200)
class Reservation(models.Model):
start = models.DateField(verbose_name='Заезд', auto_now=False, auto_now_add=False)
end = models.DateField(verbose_name='Выезд', auto_now=False, auto_now_add=False)
hasRefund = models.BooleanField(verbose_name='Возвратная бронь', default=True)
room = models.ForeignKey('Room', verbose_name='Номер', on_delete=models.CASCADE)
day = models.ManyToManyField(Day, blank=True)
check_in_time = models.CharField(verbose_name='Время заезда', max_length=200)
check_out_time = models.CharField(verbose_name='Время выезда', max_length=200)
guest_name = models.CharField(verbose_name='Имя гостя', max_length=200, blank=True)
payed = models.BooleanField(verbose_name='Оплачено', default=False)
class Room(models.Model):
name = models.CharField(max_length = 200, null=True)
Views
class ReservationCreateAPIView(CreateAPIView):
queryset = Reservation.objects.all()
serializer_class = ReservationSerializer
Serializers
class DaySerializer(serializers.ModelSerializer):
class Meta:
model = Day
fields = [
'date',
'price',
'paymentMethod',
]
class RoomSerializer(serializers.ModelSerializer):
class Meta:
model = Room
fields = [
'pk',
'name',
]
class ReservationSerializer(serializers.ModelSerializer):
room = RoomSerializer
day = DaySerializer(many=True)
class Meta:
model = Reservation
fields = [
'start',
'end',
'hasRefund',
'room',
'day',
'check_in_time',
'check_out_time',
'guest_name',
'payed',
]
def create(self, validated_data):
day_data = validated_data.pop('day')
room_data = validated_data.pop('room')
reservation = Reservation.objects.create(**validated_data)
room = Room.objects.get_or_create(name=room_data['name'])
reservation.room.add(room)
for day in day_data:
day, created = Day.objects.get_or_create(date=day['date'], price=day['price'], paymentMethod=day['paymentMethod'])
reservation.day.add(day)
return reservatrion
Data, that I try to save
{
"start": "2017-12-12",
"end": "2017-12-12",
"hasRefund": false,
"room": 2,
"day": [ {
"date": "2017-12-12",
"price": "2",
"paymentMethod": "3"
},
{
"date": "2017-12-12",
"price": "2",
"paymentMethod": "3"
}
],
"check_in_time": "14-00",
"check_out_time": "12-00",
"guest_name": "Ivan",
"payed": false
}
Response that I get
IntegrityError at /core/create/
NOT NULL constraint failed: core_reservation.room_id
What Am I doing wrong ?

Answer 1

You try to create a Reservation without its Room. Your reservation model doesn't allow a null value for its room.
One way is to create a room first, then assign it to the reservation:
room_data = validated_data.pop('room')
room = Room.objects.get_or_create(name=room_data['name'])
validated_data.update({'room': room})
reservation = Reservation.objects.create(**validated_data)
You can also simply allow reservations without a room and add the room afterwards. In your model use:
room = models.ForeignKey(
'Room',
null=True, blank=True,
verbose_name='Номер',
on_delete=models.CASCADE,
)
Then add the room to a reservation instance:
room_data = validated_data.pop('room')
reservation = Reservation.objects.create(**validated_data)
room = Room.objects.get_or_create(name=room_data['name'])
reservation.room = room
reservation.save()