Django多对多型号DRF [英] Django many-to-many model DRF

问题描述

我有以下模型结构：

  class Project（models.Model）：
 author = models。 ManyToManyField（Account）
 name = models.CharField（max_length = 40，default ='NewBook'）
 
 class Account（AbstractBaseUser）：
 email = models.EmailField（unique =真的）
 username = models.CharField（max_length = 40，unique = True）
 first_name = models.CharField（max_length = 40，blank = True）
 last_name = models.CharField（max_length = 40，blank = True）
 tagline = models.CharField（max_length = 140，blank = True）
 is_admin = models.BooleanField（default = False）
 created_at = models.DateTimeField（auto_now_add = 
 updated_at = models.DateTimeField（auto_now = True）
 objects = AccountManager（）
 USERNAME_FIELD ='email'
 REQUIRED_FIELDS = ['username'] 
  

我的看法如下：

  class ProjectViewSet（viewsets.ModelViewSet）：
 queryset = Project.object s.order_by（' -  name'）
 serializer_class = ProjectSerializer 
 
 def perform_create（self，serializer）：
 instance = serializer.save（author = self.request.user） 
 return super（ProjectViewSet，self）.perform_create（serializer）
  

调用视图函数在数据库中创建一个分类器。但是之后，我收到以下错误：

TypeError：'Account'对象不可迭代

错误在此行中抛出：

  instance = serializer。保存（author = self.request.user）
  

任何人都可以帮助我吗？ >

解决方案

这里有两个问题：

1. 显示M2M领域的嵌套关系：

如果该字段用于表示一对多关系，您应该添加许多= True 标记到序列化程序字段。

所以你需要添加许多= True 到 AccountSerializer ：

  author = AccountSerializer（read_only = True，required = False，many = 
  

2. A 可写嵌套序列化程序：







默认情况下嵌套的序列化程序是只读。如果要支持对嵌套序列化程序字段的写入操作，则需要创建 create（）和/或 update（）方法，以便明确指定如何保​​存子关系。




所以，如果你看这个例子和文档似乎需要实现创建或更新方法。




I have the following model structure:

class Project(models.Model):
  author = models.ManyToManyField(Account)
  name = models.CharField(max_length=40, default='NewBook')

class Account(AbstractBaseUser):
  email = models.EmailField(unique=True)
  username = models.CharField(max_length=40, unique=True)
  first_name = models.CharField(max_length=40, blank=True)
  last_name = models.CharField(max_length=40, blank=True)
  tagline = models.CharField(max_length=140, blank=True)
  is_admin = models.BooleanField(default=False)
  created_at = models.DateTimeField(auto_now_add=True)
  updated_at = models.DateTimeField(auto_now=True)
  objects = AccountManager()
  USERNAME_FIELD = 'email'
  REQUIRED_FIELDS = ['username']

My view looks like this:

class ProjectViewSet(viewsets.ModelViewSet):
  queryset = Project.objects.order_by('-name')
  serializer_class = ProjectSerializer

  def perform_create(self, serializer):
    instance = serializer.save(author=self.request.user)
    return super(ProjectViewSet, self).perform_create(serializer)

After calling the view function, a classifier gets created in the database. But after that, I get the following error:

TypeError: 'Account' object is not iterable

The error gets thrown in this line:

instance = serializer.save(author=self.request.user)

Anyone how can help me with this?

解决方案

There are two problems here:

1. Showing nested relationships for M2M field:

If the field is used to represent a to-many relationship, you should add the many=True flag to the serializer field.

So you need to add many=True to AccountSerializer:

author = AccountSerializer(read_only=True, required=False, many=True)

2. A writable nested serializer:

By default nested serializers are read-only. If you want to support write-operations to a nested serializer field you'll need to create create() and/or update() methods in order to explicitly specify how the child relationships should be saved.

So if you look at the example and the documentation it seems that you need to implement create or update method.

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