复制 Django Model 输入到另一个 Django 数据库

Question

我试图弄清楚是否有一种方法，一旦我将某些内容上传到我的 Django 数据库文件之一，同样的上传也会上传到另一个数据库文件，所以如果我 go 删除其中一个，它会被保存在另一个。

class CompanyInfo(models.Model):
  company_name = models.CharField("Company Name", unique=True, max_length=50, default="")

# Identifiers
identifier = models.IntegerField(default=0)



# Company Information
sector = models.CharField("Sector", max_length=50,default="")
location = models.CharField("Location", max_length=100, default="")
year_founded = models.IntegerField("Year Founded", default=2000)
company_description = models.TextField("Company Description", default="")
state_registered_in = models.CharField("State of Registration",  choices=states_list, max_length=2, default=2)
company_url = models.URLField("Company URL", max_length=200, default="", blank=True, null=True)
phone_number = models.CharField("Phone Number", max_length=20,default="")
company_logo_url = models.ImageField("Company Logo", upload_to=None, height_field=None, width_field=None, max_length=100, blank=True, null=True)
facebook = models.URLField("Facebook URL", max_length=200, default="", blank=True, null=True)
linkedin = models.URLField("Linkedin URL", max_length=200, default="", blank=True, null=True)
instagram = models.URLField("Instagram URL", max_length=200, default="", blank=True, null=True)
email = models.EmailField("Email Address", max_length=40,default="")




def __str__(self):
    return "{} from {}".format(self.company_name, self.location)

Basically, once these values are created for the "CompanyInfo" class, I want it to also upload itself into another Django class in the exact same way, so if I eventually delete the input in the "CompanyInfo" class, there will still be a保存在另一个创建的数据库中的版本。

Answer 1

有几个选项，例如覆盖 save 或使用 model 管理器，但最简单和更可测试的方法是使用 post_save 信号： https://docs.djangoproject.com/en/dev/ref/signals/#post-save

这允许您获取已保存和更新的 model 实例，但请注意，当进行.update()调用时，会跳过信号，这可能是不可取的。

保存到备份数据库的方法是编写信号以提取所有字段并重新保存。 我会避免使用update_fields ，因为一些开发人员不会使用它（它有助于优化查询）。

def save_to_backup(sender, instance, created: bool, using: str, **kwargs):
    if using == "default":
        # You don't want to continuously save/i.e. infinite loop
        return
    fields = instance._meta.get_all_field_names()
    sender.objects.using("backup_alias").save(**{field: instance._meta.get_field(field) for field in fields})