Getting NOT NULL constraint failed: locations_location.city

When I try to create an object through DRF serailizers in my api, I get the error NOT NULL constraint failed: locations_location.city_id.

I looked at a similar here and the solution provided seems to be exactly what I had to begin with.

My models:

class City(models.Model):
    code = models.CharField(max_length=4, default="", blank=False, unique=True)
    name = models.CharField(max_length=40, default="", blank=False, unique=True)
    time_added = models.DateTimeField(auto_now_add=True)

    def __str__(self):
        return f"{self.name}, ({self.code})"

    class Meta:
        verbose_name = "City"
        verbose_name_plural = "Cities"


class Location(models.Model):
    status_choice = (
        ("Available", "Available"),
        ("Unavailable", "Unavailable"),
        ("Active", "Active"),
    )
    city = models.ForeignKey(City, on_delete=models.CASCADE, related_name="locations")
    name = models.CharField(max_length=256, default="", blank=True)
    rent = models.DecimalField(max_digits=7, decimal_places=2)
    email = models.EmailField(max_length=64)
    phone = models.CharField(max_length=20, default="", blank=True)
    lon = models.DecimalField(max_digits=7, decimal_places=5, blank=True, null=True)
    lat = models.DecimalField(max_digits=7, decimal_places=5, blank=True, null=True)
    street_number = models.CharField(max_length=50, null=True)
    street_name = models.CharField(max_length=50, null=True)
    postal_code = models.CharField(max_length=50, null=True)
    status = models.CharField(max_length=50, choices=status_choice, default="Available")
    time_added = models.DateTimeField(auto_now_add=True)

    def __str__(self):
        return f"{self.name} {self.status}"

My serailizers:


class CitySerializer(serializers.ModelSerializer):
    locations = serializers.PrimaryKeyRelatedField(many=True, read_only=True)

    class Meta:
        model = City
        fields = "__all__"

    def create(self, validated_data):
        return City.objects.create(**validated_data)


class LocationSerializer(serializers.ModelSerializer):
    location_events = serializers.PrimaryKeyRelatedField(many=True, read_only=True)
    booked_days = serializers.PrimaryKeyRelatedField(many=True, read_only=True)

    class Meta:
        model = Location
        fields = "__all__"
        depth = 1

    def create(self, validated_data):
        city = serializers.PrimaryKeyRelatedField(  # noqa
            many=False, queryset=City.objects.all()
        )
        return Location.objects.create(**validated_data)

This is the fake test data passed to the api in POST request:

{
 "name": "Darmstadt Hotel", 
 "city": 1,
 "email": "[email protected]", 
 "phone": " 49(0)7219 993238", 
 "rent": 275.38, 
 "lat": 52.9427, 
 "lon": 12.1076, 
 "street_name": "Eimerstra\\u00dfe", 
 "street_number": "34", 
 "postal_code": "80843", 
 "status": "Available"
}

A city with id of 1 exists in the database and is accessible through the api.

CodePudding user response：

Firstly, you have the city field in your LocationSerializer inside the create method, that must be an error? It should be the line below booked_days = .... I'm not sure this will solve the problem however.

class LocationSerializer(serializers.ModelSerializer):
    location_events = serializers.PrimaryKeyRelatedField(many=True, read_only=True)
    booked_days = serializers.PrimaryKeyRelatedField(many=True, read_only=True)
    city = serializers.PrimaryKeyRelatedField(  # noqa
        many=False, queryset=City.objects.all()
    ) # Move it here

    class Meta:
        model = Location
        fields = "__all__"
        depth = 1

    def create(self, validated_data):
        return Location.objects.create(**validated_data)