Django - "Invalid type. Expected pk error received by str"
I my django-rest-framework I have the following models:
Basically, each trip has one final destination and may have several intermediate destinations.
models.py:
class Destination(models.Model):
name=models.CharField(max_length=30)
class Ride(models.Model):
driver = models.ForeignKey('auth.User', related_name='rides_as_driver')
destination=models.ForeignKey(Destination, related_name='rides_as_final_destination')
leaving_time=models.TimeField()
num_of_spots=models.IntegerField()
passengers=models.ManyToManyField('auth.User', related_name="rides_as_passenger")
mid_destinations=models.ManyToManyField(Destination, related_name='rides_as_middle_destination')
serializers.py - RideSerializer
class RideSerializer(serializers.ModelSerializer):
driver = serializers.ReadOnlyField(source='driver.user.username')
class Meta:
model = Ride
fields = ('driver', 'destination', 'leaving_time',
'num_of_spots', 'passengers', 'mid_destinations')
read_only_fields = ('driver', 'passengers', 'mid_destinations')
Problem - When I try to POST / rides / to add a ride - for example{destination=LA, leaving_time=19:45, num_of_spots=4}
I get an error "destination":["Incorrect type. Expected pk value, received str."]}
a couple of questions:
-
What is this error? if I have an endpoint as a foreign key in the Ride model , does that mean that the destination I'm adding must already be in the Targets table ?
-
How do I fix this error?
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The problem is that you are passing the name
bound object Destination
to the serializer instead of passing pk
/ id
object Destination
. So the Django REST framework sees this and complains because it can't resolve LA
into an object.
It looks like you can actually search for aSlugRelatedField
, which allows you to identify objects by slug ( LA
in this case) instead of their primary keys.
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