与 Django 信号相关的查询

Question

首先，当通过 Signals 创建用户模型时，会创建 Profile 和 Seller 模型。我想要做的是当第一次创建或更新配置文件模型时，我希望 Seller 模型的所有字段与Profile的所有字段。和我第一次创建Seller模型时一样，我也希望Profile Model的所有字段都与Seller模型的字段相同。但是，我不知道该怎么做？

from typing import Tuple
from django.db import models
from django.contrib.auth.models import User
from django.urls import reverse
from django.db.models.fields import DecimalField
from django.dispatch import receiver
from django.db.models.signals import post_save

class Profile(models.Model):
    user = models.OneToOneField(User, on_delete=models.CASCADE, null=True, blank=True) #cascade is for deleting the customer
    first_name = models.CharField(max_length=10, null=True)
    second_name=models.CharField(max_length=10,null=True)
    email = models.EmailField(max_length=70, null=True,blank=True)


@receiver(post_save, sender=User)
def create_profile(sender, instance,created,**kwargs):#Signal receivers must accept keyword arguments (**kwargs).
    if created:
        Profile.objects.create(user=instance)
    ...

@receiver(post_save, sender=Profile)
def create_seller(sender, instance,created,**kwargs):#Signal receivers must accept keyword arguments (**kwargs).
    if created:
        Seller.objects.create(user=instance)

class Seller(models.Model):
    user = models.OneToOneField(Profile, on_delete=models.CASCADE, null=True, blank=True) #cascade is for deleting the customer
    first_name = models.CharField(max_length=10, null=True)
    second_name=models.CharField(max_length=10,null=True)
    email = models.EmailField(max_length=70, null=True,blank=True)
         
 ...

Answer 1

如果created=True 表示创建了Profile 对象。否则如果created=False 表示Profile 对象已更新。

created=True 需要创建Seller 对象，created=False 需要更新Seller 对象。

你可以这样做：

@receiver(post_save, sender=Profile)
def update_or_create_seller(sender, instance, created, **kwargs):
    if created:
        Seller.objects.create(
            user=instance.user, 
            first_name=instance.first_name,
            second_name=instance.second_name,
            email=instance.email
        )
    else:
        seller = instance.user.seller
        seller.first_name = instance.first_name
        seller.last_name = instance.second_name
        seller.email = instance.email
        seller.save()      

另外请注意，除非您在 OneToOneField 中定义 related_name，否则 Django 将使用 小写 模型名称来访问相关对象。所以，instance.user.seller 应该可以工作。