Question

我使用Django，我有两个模型：

class Source(models.Model):
  def __str__(self):
    return "Test"



class SecurityGroup(models.Model)
  name = models.CharField(max_length=20)
  source = models.ForeignKey(Source)

我希望当我添加一个新的SecurityGroup时，会自动附加一个带有他ID的新Source，而这个ID将是SecurityGroup中的源阵营。

我一直在寻找，我发现覆盖方法save（），但我不知道该怎么办..

谢谢！

Answer 1

了解signals。

post_save版本：

from django.db.models.signals import post_save
from django.dispatch.dispatcher import receiver

@receiver(post_save, sender=SecurityGroup)
def add_source(sender, instance, created, **kwargs):
    if created:
        source = Source()
        source.save()
        instance.source = source
        instance.save()

pre_save版本：

from django.db.models.signals import pre_save
from django.dispatch.dispatcher import receiver

@receiver(pre_save, sender=SecurityGroup)
def add_source(sender, instance, **kwargs):
    if instance.source is None:
        source = Source()
        source.save()
        instance.source = source

Answer 2

正如您所提到的，您可以覆盖SecurityGroup的保存方法并在那里创建一个新的Source对象：

class SecurityGroup(models.Model)
    name = models.CharField(max_length=20)
    source = models.ForeignKey(Source)

    def save(self, *args, **kwargs):
        if self.source is None:
            self.source = Source.objects.create()
        super(SecurityGroup, self).save(*args, **kwargs)

添加具有外键的模型

2 个答案: