DRF IntegrityError：NOT NULL约束失败：user_id [英] DRF IntegrityError: NOT NULL constraint failed: user_id

问题描述

我不知道如何将用户对象传递给以下序列化器：

I can't figure out how to pass user object to the following serializer:

class ReviewSerializer(serializers.ModelSerializer):
    user = UserSerializer(read_only=True)

    class Meta:
        model = Review
        fields = ('pk', 'title', 'user', 'movie', 'timestamp', 'review_text',)

我有此视图集：

class ReviewsViewSet(viewsets.ModelViewSet):
    queryset = Review.objects.all()
    serializer_class = ReviewSerializer

此模型：

class Review(models.Model):
    title = models.CharField(max_length=255)
    user = models.ForeignKey(User, on_delete=models.CASCADE, related_name='reviews')
    movie = models.ForeignKey(Movie, on_delete=models.CASCADE, related_name='reviews')
    review_text = models.TextField()
    timestamp = models.DateTimeField(auto_now_add=True)

    def __str__(self):
        return '{movie} review by {user}'.format(user=self.user, movie=self.movie)

我的JavaScript请求如下：

My javascript request looks like this:

return axios({
  method: 'post',
  url: 'http://localhost:8000/api/reviews/',
  data: { // Using data from Vue
    title: this.review_title,
    movie: this.id,
    review_text: this.review_text,
    user: JSON.stringify(this.user)
  },
  headers: {
    'Content-Type': 'application/json',
    Authorization: `JWT ${token}`
  }
})

它给了我此traceback 。

我应该如何将用户对象传递给请求？

How should I pass the user object to the request?

请先谢谢。

推荐答案

删除 read_only = True 来自序列化器

Remove read_only=True from serializer

class ReviewSerializer(serializers.ModelSerializer):
    user = UserSerializer()

    class Meta:
        model = Review
        fields = ('pk', 'title', 'user', 'movie', 'timestamp', 'review_text',)

如果设置 read_only = True ，则DRF 不会从输入源获取值 ，即使在那里



从文档中

If you set read_only=True, the DRF will not takes the value from input source even if it's there

From the doc,

只读字段包含在API输出中，但在创建或更新操作期间不应包含在输入中的
。序列化器
输入中错误包含的所有
'read_only'字段都将被忽略。

Read-only fields are included in the API output, but should not be included in the input during create or update operations. Any 'read_only' fields that are incorrectly included in the serializer input will be ignored.

将此设置为 True 以确保在序列化
表示形式时使用该字段，而在反序列化期间创建或更新实例
时不使用该字段。

Set this to True to ensure that the field is used when serializing a representation, but is not used when creating or updating an instance during deserialization.

默认为 False

Defaults to False

更新

您应覆盖 create（） ReviewSerializer 的$ c> 方法为

class ReviewSerializer(serializers.ModelSerializer):
    user = UserSerializer()

    def create(self, validated_data):
        user_dict = validated_data.pop('user')
        user_obj, created = User.objects.get_or_create(**user_dict)
        return Review.objects.create(user=user_obj, **validated_data)

    class Meta:
        model = Review
        fields = ('pk', 'title', 'user', 'movie', 'timestamp', 'review_text',)

仅用于调试目的

class ReviewsViewSet(viewsets.ModelViewSet):
    queryset = Review.objects.all()
    serializer_class = ReviewSerializer

    def create(self, request, *args, **kwargs):
        print(request.data)  # print here <<<<
        return super(ReviewsViewSet, self).create(request, *args, **kwargs)

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