如何在 Django Rest Framework 中顯示 ManyToMany 字段的值而不是它們的 ID？

Question

模型：

class Genre(models.Model):
    name = models.CharField(max_length=100)

    def __str__(self):
        return self.name


class Song(models.Model):
    name = models.CharField(max_length=200)
    genre = models.ManyToManyField(Genre)

序列化器：

class GenreSerializer(serializers.ModelSerializer):

    class Meta:
        model = Genre
        fields = '__all__'


class SongSerializer(serializers.ModelSerializer):

    class Meta:
        model = Song
        fields = '__all__'

    def to_representation(self, instance):
        rep = super().to_representation(instance)
        print(GenreSerializer(instance.name).data)
        return rep

序列化程序中的上述打印給出： {'name': None} 並且響應是使用流派 ID 而不是值：

[
    {
        "id": 1,
        "name": "Abcd",
        "genre": [
            1,
            3
        ]
    }
]

其中流派1. 流行和3. 搖滾

我可以對 to_representation 進行哪些更改以打印值而不是流派的 id，流派是帶有歌曲模型的 ManyToManyField。

Answer 1

你快到了，試試這個

class SongSerializer(serializers.ModelSerializer):
    class Meta:
        model = Song
        fields = '__all__'

    def to_representation(self, instance):
        rep = super().to_representation(instance)
        rep["genre"] = GenreSerializer(instance.genre.all(), many=True).data
        return rep

Answer 2

雖然上面的答案是正確的，但你也可以這樣做。

class SongSerializer(serializers.ModelSerializer):

    genre= serializers.StringRelatedField(many=True)

    class Meta:
       model = Song
       fields = '__all__'

https://www.django-rest-framework.org/api-guide/relations/#stringrelatedfield