using primarykeyrelated for post and string for get call in django rest framework

I have a model in which some fields are a foreign key to another model. Hence while django error creating the object of that model I have to use primary key but while calling get api I need to show those fields as stringrelated field. How to achieve that??

My model:

class Example(models.Model):      tour = models.ForeignKey(         Package,         on_delete=models.CASCADE,         null=True,         related_name="example"     )      site = models.ForeignKey(                                 Destination,                                 on_delete=models.CASCADE,                                 null= True,                                 related_name= "example",     )            location = models.CharField(blank=True)     /...........other fields........../ 

My serializer:

class ExampleSerializer(serializers.ModelSerializer):      # tour = serializers.StringRelatedField()     # site = serializers.StringRelatedField()      class Meta:         model = OnlineClass         fields = ['id','tour','site','other fields.....']      def to_representation(self, instance):         data = super(ExampleSerializer, self).to_representation(instance)         return data 

Here while creating the example object, I need to pass tour and site as ids but while calling list method I need to show both fields as string related fields. As I define them as stringrelated field as above (later commented out) , I can create the object but those fields will django error be set as null. I don't want to make another serializer. How to achieve this??

Answers 1: of using primarykeyrelated for post and string for get call in django rest framework

tour= serializers.SlugRelatedField(     read_only=True,     slug_field='id' )