Implementing Serializer relations

Django models have three types of relational fields – ForeignKey, ManyToManyField, and OneToOneField (all of them support reverse relationships too). So far, we have learned how to use model serializers efficiently, but let’s now explore how we can work with related fields in Serializers.

By default, when a model has any related field, ModelSerializer will link the associated field to PrimaryKeyRelatedField in the serializer definition. A DRF serializer will use PrimaryKeyRelatedField for all kinds of related field serializers, with different options passed.

Here, we will learn how to create related field serializers:

• For ForeignKey, the DRF model serializer assigns PrimaryKeyRelatedField to the serializer
• For OneToOneField, the DRF model serializer assigns PrimaryKeyRelatedField to the serializer with an additional UniqueValidator attached
• For ManyToManyField, the DRF model serializer assigns PrimaryKeyRelatedField...