DRF 将模型中的单个字段关联起来

Question

Yes, I know there are a lot of questions about DRF serializer relations that are already answered. But non of them could help me or I'm to dump to get it...

I have the following models:

class User(models.Model):
    id = models.IntegerField(primary_key=True)
    name = models.CharField(max_length=30)
    ...

class Person(models.Model):
    id = models.IntegerField(primary_key=True)
    person_id = models.IntegerField()
    birthdate = models.DateTimeField(blank=True, null=True)
    ...

Now I want the birthdate field from Person in User like this:

{
    "id": 397,
    "name": "name",
    "birthdate": "2015-11-11T00:00:00Z",
    ...
}

So I did this:

class UserSerializer(serializers.ModelSerializer):
    birthdate = serializers.SerializerMethodField()

    class Meta:
        model = User

    def get_birthdate(self, obj):
        person = PersonSerializer(Person.objects.get(person_id=obj.pk)).data
        return person['birthdate']

It works yea but there has to be a better way. I have multiple fields I want to relate in this way and the result would be awkward code so please help me!

Answer 1

Thanks again to dhke. He helped me in the comments to find the answer to my question.

The only thing I had to do is adding a OneToOneField to Person :

class Person(models.Model):
    id = models.IntegerField(primary_key=True)
    person_id = models.OneToOneField(User, related_name='person')
    birthdate = models.DateTimeField(blank=True, null=True)
    ...

Then add the following field to UserSerializer :

birthdate = serializers.DateTimeField(source='person.birthdate')

And that is the whole magic.

(I love DRF!)