在Django Rest Framework中列出某些内容时，如何不仅显示对象的外键？

Question

I'm working on a problem in one class called Tour, which includes an Artist foreign key. I need to show more than just its foreign key. How can I do that while keeping all of CRUD functional?

I tried to add depth = 1 to the Meta class in the serializers. That works, but upon attempting to create a new object, I get the error NOT_NULL CONSTRAINT FAILED. Then I got rid of that and instead added artist = ArtistSerializer to the TourSerializer, but that still doesn't do it, even though I've seen it work in a tutorial. The issue with using artist=ArtistSerializer() is that when I try to create the object, I pass the foreign key, but it doesn't seem to recognize it as a valid field. It's like I didn't type anything at all into the field. Every time I get it to properly list it, the creation doesn't work as intended. Here's how my code looks right now:

class TourSerializer(ModelSerializer):
artist = ArtistSerializer()

class Meta:
    model = Tour
    fields = ['artist', 'start', 'end', 'country', 'id', 'created_at', 'updated_at']
    read_only_fields = ['id', 'created_at', 'updated_at']

The models for Tour and Artist are as follows:

class Tour(models.Model):
artist = models.ForeignKey('core.Artist', on_delete=models.PROTECT)
start = models.DateField(auto_now=False, auto_now_add=False)
end = models.DateField(auto_now=False, auto_now_add=False)
country = models.CharField(max_length=70)
created_at = models.DateField(auto_now_add=True)
updated_at = models.DateField(auto_now=True)


class Artist(models.Model):
user = models.ForeignKey('core.User', on_delete=models.PROTECT)
name_alternative = models.CharField(max_length=50)
country = models.CharField(max_length=50)
bio = models.TextField(max_length=2500)
profile_image = models.ImageField(upload_to='user/profile', null=True, blank=True)
tags = models.ManyToManyField('core.Tag', blank=True)
labels = models.ManyToManyField('core.Label', blank=True)
created_at = models.DateField(auto_now_add=True)
updated_at = models.DateField(auto_now=True)

And just for good measure, Here's the artist serializer:

class ArtistSerializer(ModelSerializer):
user = serializers.HiddenField(
    default=serializers.CurrentUserDefault()
)

class Meta:
    model = Artist
    fields = ['id', 'user', 'name_alternative', 'labels', 'tags',
              'country', 'bio', 'profile_image', 'created_at', 'updated_at']
    read_only_fields = ['id', 'created_at', 'updated_at', 'user']

This is my first question here, so let me know if I missed any vital piece of code.

Answer 1

Probably you can update the TourSerializer 's to_represent() method. For example:

class TourSerializer(ModelSerializer):
    class Meta:
        model = Tour
        fields = ['artist', 'start', 'end', 'country', 'id', 'created_at', 'updated_at']
        read_only_fields = ['id', 'created_at', 'updated_at']

    def to_representation(self, instance):
        response = super().to_representation(instance)
        response['artist'] = ArtistSerializer(instance.artist).data
        return response

In that way, when you are creating/updating the Tour instance, you can pass the FK value, but when reading, you will get all the fields from Artist object.