How To Access Other Model Field From Serializer Related Field?

have following model class Search(models.Model): trip_choice = ( ('O', 'One way'), ('R', 'return') ) booking_id = models.IntegerField(db_index=True, uniq

Solution 1:

You can define a SerializerMethodField like this:

class AddBookSerializer(BookSerializer):
    booking_id = serializers.IntegerField(source='flight_search.booking_id')
    return_id = serializers.SerializerMethodField()

    class Meta(BookSerializer.Meta):
        fields = (
            'booking_id',
            'flight_id',
            'return_id',
        )

    # by default the method name for the field is `get_{field_name}`
    # as a second argument, current instance of the `self.Meta.model` is passed
    def get_return_id(self, obj):
        if obj.flight_search.trip_choice == 'R':
            # your logic here
        else:
            return obj.return_id