Django 管理员显示创建的实例，但在 DRF 视图中看不到它

Question

我正在学习有关 DRF 的课程。它基本上是在创建一个问答网站。现在我尝试使用 DRF 界面回答问题。

但是当我查看问题时，它仍然显示答案计数为零。

但是答案在 Django 管理面板上是可见的。

我的代码是： 模型.py文件

class Question(models.Model):
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)
    content = models.CharField(max_length=240)
    slug = models.SlugField(max_length=240, unique=True)
    author = models.ForeignKey(settings.AUTH_USER_MODEL,
                               on_delete=models.CASCADE,
                               related_name="questions")

    def __str__(self):
        return self.content


class Answer(models.Model):
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)
    body = models.TextField()
    question = models.ForeignKey(Question,
                                 on_delete=models.CASCADE,
                                 related_name="answers", null=True)
    author = models.ForeignKey(settings.AUTH_USER_MODEL,
                               on_delete=models.CASCADE)
    voters = models.ManyToManyField(settings.AUTH_USER_MODEL,
                                    related_name='votes')

    def __str__(self):
        return f'{self.body} by {self.author.username}'

serializers.py 文件：

from rest_framework import serializers
from ..models import (Answer, Question)


class AnswerSerializer(serializers.ModelSerializer):
    author = serializers.StringRelatedField(read_only=True)
    created_at = serializers.SerializerMethodField(read_only=True)
    likes_count = serializers.SerializerMethodField(read_only=True)
    user_has_voted = serializers.SerializerMethodField(read_only=True)

    class Meta:
        model = Answer
        exclude = ['question', 'voters', 'updated_at']

    def get_created_at(self, instance):
        return instance.created_at.strftime("%B %d %y")

    def get_likes_count(self, instance):
        return instance.voters.count()

    def get_user_has_voted(self, instance):
        request = self.context.get('request')
        return instance.voters.filter(pk=request.user.pk).exists()


class QuestionSerializer(serializers.ModelSerializer):
    author = serializers.StringRelatedField(read_only=True)
    created_at = serializers.SerializerMethodField(read_only=True)
    slug = serializers.SlugField(read_only=True)
    answers_count = serializers.SerializerMethodField(read_only=True)
    user_has_answered = serializers.SerializerMethodField(read_only=True)

    class Meta:
        model = Question
        exclude = ['updated_at']

    def get_created_at(self, instance):
        return instance.created_at.strftime("%B %d %y")

    def get_answers_count(self, instance):
        return instance.answers.count()

    def get_user_has_answered(self, instance):
        request = self.context.get('request')
        return instance.answers.filter(author=request.user.pk).exists()

还有views.py文件

from rest_framework import generics, viewsets
from rest_framework.generics import get_object_or_404
from rest_framework.exceptions import ValidationError
from rest_framework.permissions import IsAuthenticated


from ..models import Question, Answer
from .serializers import QuestionSerializer, AnswerSerializer
from .permissions import IsAuthorOrReadOnly


class QuestionViewSet(viewsets.ModelViewSet):
    queryset = Question.objects.all()
    lookup_field = 'slug'
    serializer_class = QuestionSerializer
    permissions_class = [IsAuthorOrReadOnly, IsAuthenticated]

    def perform_create(self, serializer):
        serializer.save(author=self.request.user)


class AnswerCreateAPIView(generics.CreateAPIView):
    queryset = Answer.objects.all()
    serializer_class = AnswerSerializer
    permission_classes = [IsAuthenticated]

    def perform_create(self, serializer):
        request_user = self.request.user
        kwarg_slug = self.kwargs.get("slug")
        question = get_object_or_404(Question, slug=kwarg_slug)

        if question.answers.filter(author=request_user).exists():
            raise ValidationError('You Have Already Answered')
        serializer.save(author=self.request.user)

Answer 1

如果您在AnswerSerializer 中排除product，则需要明确提供question 以创建答案

class AnswerCreateAPIView(generics.CreateAPIView):
    ...
    def perform_create(self, serializer):
        ...
        serializer.save(author=self.request.user, question=question)