Django - 在创建父对象时创建所有外键对象

Question

考虑下面的代码，其中我有一个父模型，以及与父模型相关的所有子模型 ForeignKey关系。每个 child 都可能有自己的 child ，让整个家庭看起来像一个树形结构。

class Parent(models.Model):
    field = models.CharField(max_length=100, primary_key=True)

class Child_1(models.Model):
    parent = models.ForeignKey(Parent, models.CASCADE, related_name='aa')

class Child_2(models.Model):
    parent = models.ForeignKey(Parent, models.CASCADE, related_name='aa')

class Child_1_Child_1(models.Model):
    parent = models.ForeignKey(Child_1, models.CASCADE, related_name='aa')

class Child_1_Child_2(models.Model):
    parent = models.ForeignKey(Child_1, models.CASCADE, related_name='aa')

为 Parent 创建对象后，我想创建所有的子对象。

我想我可以像这样创建所有子对象:

parent = Parent.objects.create(**kwargs)
child_1 = Child_1.objects.create(parent=parent)
child_2 = Child_2.objects.create(parent=parent)
child_1_child_1 = Child_1_Child_1.objects.create(parent=child_1)
child_1_child_2 = Child_1_Child_2.objects.create(parent=child_1)
...

但是你知道，这看起来不太好。是否有任何内置的 Django 方法可以在链中处理这种父子对象的创建？

Answer 1

覆盖 save() 模型方法为，

class Parent(models.Model):
    field = models.CharField(max_length=100, primary_key=True)

    def save(self, *args, **kwargs):
 is_new = not self.pk
 super().save(*args, **kwargs)
 if is_new:
 Child_1.objects.create(parent=self)
 Child_2.objects.create(parent=self)


class Child_1(models.Model):
    parent = models.ForeignKey(Parent, models.CASCADE, related_name='aa')

    def save(self, *args, **kwargs):
 is_new = not self.pk
 super().save(*args, **kwargs)
 if is_new:
 Child_1_Child_1.objects.create(parent=self)


class Child_2(models.Model):
    parent = models.ForeignKey(Parent, models.CASCADE, related_name='aa')

    def save(self, *args, **kwargs):
 is_new = not self.pk
 super().save(*args, **kwargs)
 if is_new:
 Child_1_Child_2.objects.create(parent=self)


class Child_1_Child_1(models.Model):
    parent = models.ForeignKey(Child_1, models.CASCADE, related_name='aa')


class Child_1_Child_2(models.Model):
    parent = models.ForeignKey(Child_1, models.CASCADE, related_name='aa')