python - 如何使用模型序列化程序序列化 django-rest 中的一对多关系？

Question

这些是我的模型和序列化器。我想要问题模型的表示以及问题被问到的人员列表。

我正在尝试:

@api_view(['GET', 'PATCH'])
def questions_by_id(request,user,pk):
    question = Question.objects.get(pk=pk)
    if request.method == 'GET':
        serializer = QuestionSerializer(question)
        return Response(serializer.data)

但我得到一个空字典 ({})。但是，当我从 QuestionSerializer 中删除 asked 字段时，我得到了 Question 的完整表示以及很好地序列化的 Places 。我错过了什么？

class AskedToSerializer(serializers.ModelSerializer):
    class Meta:
        model = AskedTo
        fields = ('to_user', 'answered')

class QuestionSerializer(serializers.ModelSerializer):
    class Meta:
        model = Question
        places = PlaceSerializer(many=True, required=False)
        asked = AskedToSerializer(source='askedto_set', many=True)
        fields = ('id', 'created_on', 'title', 'places', 'answered','asked')
        extra_kwargs = {'created_by': {'read_only': True}}

class Question(BaseModel):
    title = models.CharField(max_length=200, null=False)
    places = models.ManyToManyField(Place, blank=True)
    answered = models.BooleanField(default=False)

class AskedTo(BaseModel):
    ques = models.ForeignKey(Question, on_delete=models.CASCADE)
    to_user = models.ForeignKey(settings.AUTH_USER_MODEL)
    replied = models.BooleanField(default=False)


class Place(models.Model):
    g_place_id = models.CharField(max_length=20,primary_key=True)
    json = models.TextField(null=True)
    name = models.CharField(max_length=40)

Answer 1

我想通了。有两个错误。

改变了这个:

class AskedToSerializer(serializers.ModelSerializer):
    class Meta:
        model = AskedTo
        fields = ('to_user', 'answered')

为此(注意字段的变化，模型和序列化器上的字段不匹配)

class AskedToSerializer(serializers.ModelSerializer):
    class Meta:
        model = AskedTo
        fields = ('to_user', 'replied')

其次，我需要在 class Meta 之外定义任何额外的字段

class QuestionSerializer(serializers.ModelSerializer):
    places = PlaceSerializer(many=True, required=False)
    asked = AskedToSerializer(source='askedto_set', many=True)    

    class Meta:
        model = Question
        fields = ('id', 'created_on', 'title', 'places', 'answered','asked')
        extra_kwargs = {'created_by': {'read_only': True}}

请注意 places 和 asked 定义的变化。