如何创建 DRF 反向深度嵌套（深度：4）Json 对象？答案

【问题标题】：How to create DRF Reverse Deep Nested (indepth : 4) Json Object?如何创建 DRF 反向深度嵌套（深度：4）Json 对象？
【发布时间】：2021-10-02 08:21:19
【问题描述】：

如何通过Project单API实现ProjectEmployee、Employee、EmployeeSpecialization、AvailableWorkField？所有这些都通过多对多关系连接。

这里我展示了一个简短的模型代码：

class Project(models.Model):
    title = models.CharField(max_length=300, primary_key=True, unique=True)


class Employee(models.Model):
    name = models.CharField(max_length=300, blank=True, null=True)


class AvailableWorkField(models.Model):
    available_field_position = models.CharField(max_length=100)


class EmployeeSpecialization(models.Model):
    employee = models.ForeignKey(Employee, related_name='employee_specialization_employee', on_delete=models.CASCADE)
    preferred_field = models.ForeignKey(AvailableWorkField, related_name='employee_specialization_available_work_field',
                                        on_delete=models.CASCADE)


class ProjectEmployee(models.Model):
    project = models.ForeignKey(Project, related_name='project_employee_project', on_delete=models.CASCADE)
    employee = models.ForeignKey(Employee, related_name='project_employee_employee', on_delete=models.CASCADE)
    project_position = models.CharField(max_length=100)

这是我的序列化器：

class AvailableWorkFieldSerializers(serializers.ModelSerializer):
    class Meta:
        model = AvailableWorkField
        fields = '__all__'


class EmployeeSpecializationSerializers(serializers.ModelSerializer):
    employee_specialization_available_work_field = AvailableWorkFieldSerializers(many=True, read_only=True)

    class Meta:
        model = EmployeeSpecialization
        fields = '__all__'


class EmployeeSerializers(serializers.ModelSerializer):
    employee_specialization_employee = EmployeeSpecializationSerializers(many=True, read_only=True)

    class Meta:
        model = Employee
        fields = '__all__'


class ProjectEmployeeSerializers(serializers.ModelSerializer):
    project_employee_employee = EmployeeSerializers(many=True, read_only=True)

    class Meta:
        model = ProjectEmployee
        fields = '__all__'


class ProjectSerializers(serializers.ModelSerializer):
    project_employee_project = ProjectEmployeeSerializers(many=True, read_only=True)

    class Meta:
        model = Project
        fields = '__all__'

我想要一个像这样的复杂嵌套 JSON 对象用于项目休息 API：

[
  {
    "title": "RevSurvey",
    "project_employee_project": [
      {
        "id": 2,
        "project_position": "Django",
        "project": "RevSurvey",
        "employee": {
          "id": 1,
          "name": "david",
          "preferred_field": [
            {
              "id": 1,
              "available_field_position": "Laravel"
            }
          ]
        }
      }
    ]
  }
]

但我期待得到：

[
  {
    "title": "RevSurvey",
    "project_employee_project": [
      {
        "id": 2,
        "project_position": "Django",
        "project": "RevSurvey",
        "employee": 1
      }
    ]
  }
]

【问题讨论】：

标签： django rest django-models django-rest-framework

【解决方案1】：

试试这个：

class ProjectEmployeeSerializers(serializers.ModelSerializer):
    employee = EmployeeSerializers(read_only=True)

    class Meta:
        model = ProjectEmployee
        fields = '__all__'

在ProjectEmployee 的上下文中，您可以通过employee 获取员工。而且由于是外键而不是反向关系，所以只有一个对象，所以不能使用many=True

【讨论】：