Django-Rest-Framework。更新兩個表

Question

我遇到更新嵌套對象的問題。 所以，我有兩個型號，其結構類似於此：

class EmployeeEvent(models.Model): 
id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False) 
event_name = models.CharField(max_length=200) 
start_date = models.DateField() 
end_date = models.DateField() 


class EmployeeEvent_Users(models.Model): 
id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False) 
employee_event = models.ForeignKey(EmployeeEvent, on_delete=models.CASCADE, related_name='employee_event_employee_list') 

employee = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE, related_name='employeeEvent_employee') 

我已經寫了下面的序列化：

class EmployeeEventUserSerializer(serializers.ModelSerializer): 
class Meta: 
    model = EmployeeEvent_Users 
    fields = ('id', 'employee',) 

class EmployeeEventSerializer(serializers.ModelSerializer): 
employee_event_users = EmployeeEventUserSerializer(required=True, many=True) 

class Meta: 
    model = EmployeeEvent 
    fields = ('event_name', 'start_date', 'end_date', 'employee_event_users',) 

def create(self, validated_data): 
    request = self.context.get('request') 
    employee_event = EmployeeEvent.objects.create(
     event_name=validated_data['event_name'], 
     start_date=validated_data['start_date'], 
     end_date=validated_data['end_date'], 
     # etc ... 
    ) 
    employeeEventUsers_data = validated_data.pop('employee_event_users', []) 

    for employeeEventUser_data in employeeEventUsers_data: 
     employeeEvent_users = EmployeeEvent_Users.objects.create(
      employee_event=employee_event, 
      employee=employeeEventUser_data['employee'], 

     ) 
    employee_event.employee_event_users = employeeEventUsers_data; 
    return employee_event 


def update(self, instance, validated_data): 

    instance.event_name = validated_data['event_name'] 
    instance.start_date = validated_data['start_date'] 
    instance.end_date = validated_data['end_date'] 
    instance.save() 

    instance.employee_event_users = validated_data.get('employee_event_users') 


    if instance.employee_event_users: 
     for employee_event_user in instance.employee_event_users: 
      employee_event_user_id = employee_event_user.get('employee_id', None) 
      if employee_event_user_id: 
       emp_user = EmployeeEvent_Users.objects.get(id=employee_event_user_id, employee_event=instance) 
       emp_user.employee = employee_event_user.get('employee', emp_user.employee) 
       emp_user.save() 
      else: 
       EmployeeEvent_Users.objects.create(employee_event=instance, **employee_event_user) 

    return instance 

截至目前，創建工作完美，更新不工作。 EmployeeEvent表正在更新，但不更新EmployeeEvent_User表。我認爲下面的邏輯是正確的，但它錯過了一些東西。任何幫助將非常感激。誰能幫忙？

Answer 1

看看本次更新方法工作更好：

def update(self, instance, validated_data): 
    instance.event_name = validated_data['event_name'] 
    instance.start_date = validated_data['start_date'] 
    instance.end_date = validated_data['end_date'] 

    # When updating children, I find it easier to delete them all 
    # and then re-add them instead of checking each one. It probably 
    # is not very efficient, however for small lists it should not 
    # matter much. 
    for emp in instance.employee_event_users.all(): 
     emp.delete() 

    # Now go through and re-add the EmployeeEvent_User 
    for employee_event_user in validated_data['employee_event_users']: 
     user = EmployeeEvent_Users.objects.create(employee_event=instance, **employee_event_user) 
     instance.employee_event_users.add(user) 

    instance.save() 
    return instance 

有兩點需要注意：我搬到了instance.save()到底。在您的測試案例中，您是在添加/編輯員工之前保存您的實例。其次，在您的測試案例中，您正在爲您的employee_event_users分配字典型對象，而不是它預期的實際對象。您可以修改測試用例，創建新用戶的位置，將其添加到列表中，然後保存（如果您不想刪除子項並重新添加它們）。下面是什麼樣子：

def update(self, instance, validated_data): 
    instance.event_name = validated_data['event_name'] 
    instance.start_date = validated_data['start_date'] 
    instance.end_date = validated_data['end_date'] 

    for employee_event_user in validated_data['employee_event_users']: 
     employee_event_user_id = employee_event_user.get('employee_id', None) 
     if employee_event_user_id: 
      emp_user = EmployeeEvent_Users.objects.get(id=employee_event_user_id, employee_event=instance) 
      emp_user.employee = employee_event_user.get('employee', emp_user.employee) 
      emp_user.save() 
     else: 
      user = EmployeeEvent_Users.objects.create(employee_event=instance, **employee_event_user) 
      user.save() 
      instance.employee_event_users.add(user) 

    instance.save() 
    return instance