Django休息框架序列化很多到很多领域

Question

如何将多对多字段序列化为某些列表,并通过休息框架返回它们？在下面的示例中,我尝试将帖子与一个与之关联的标签列表一起返回.

models.py

class post(models.Model):
    tag = models.ManyToManyField(Tag)
    text = models.CharField(max_length=100)

serializers.py

class PostSerializer(serializers.ModelSerializer):
    class Meta:
        model = Post
        fields = ("text", "tag"??)

views.py

class PostViewSet(viewsets.ReadOnlyModelViewSet):
    queryset = Post.objects.all()
    serializer_class = PostSerializer

Answer 1

你需要一个TagSerializer,class Meta有的model = Tag.之后TagSerializer被创建,修改PostSerializer与many=True一个ManyToManyField关系:

class PostSerializer(serializers.ModelSerializer):
    tag = TagSerializer(read_only=True, many=True)

    class Meta:
        ...

答案是DRF 3

Answer 2

这就是我所做的，假设一本书可以有多个作者，而一个作者可以有多个本书：关于模型：

class Author(models.Model):
    name = models.CharField(max_length=100, default="")
    last_name = models.IntegerField(default=0)

class Book(models.Model):
    authors = models.ManyToManyField(Author, related_name="book_list", blank=True)
    name = models.CharField(max_length=100, default="")
    published = models.BooleanField(default=True)

在序列化器上：

class BookSerializer(serializers.ModelSerializer):
    authors = serializers.PrimaryKeyRelatedField(queryset=Author.objects.all(), many=True)

    class Meta:
        model = Book
        fields = ('id', 'name', 'published', 'authors')


class AuthorSerializer(serializers.ModelSerializer):
    book_list = BookSerializer(many=True, read_only=True)

    class Meta:
        model = Author
        fields = ('id', 'name', 'last_name', 'book_list')

Answer 3

添加到@Brian 的答案 "tags": [{"name": "tag1"}] 可以简化为 "tags": ["tag1", "tag2",...] 以这种方式：

class PostSerializer(serializers.ModelSerializer):
    tag = TagSerializer(read_only=True, many=True)

    class Meta:
        ...

class TagSerializer(serializers.RelatedField):

     def to_representation(self, value):
         return value.name

     class Meta:
        model = Tag

更多信息：https : //www.django-rest-framework.org/api-guide/relations/#custom-relational-fields

Answer 4

默认ModelSerializer使用主键作为关系。但是，您可以使用以下Meta depth属性轻松生成嵌套表示：

class PostSerializer(serializers.ModelSerializer):
    class Meta:
        model = Post
        fields = ("text", "tag")
        depth = 1 

如文档中所述：

该depth选项应设置为整数值，该值指示在恢复为平面表示之前应遍历的关系深度。

Answer 5

这对我有用。

tag = TagSerializer(source="tag", read_only=True, many=True)