Question

当我们通过models.py或forms.py创建另一个对象时，是否可以创建对象？

models.py

class Study(models.Model):
    nameS= models.CharField(max_length=40)
def __init__(self):
    System.create(Study=self)

class System(models.Model):
    Name= models.TextField(max_length=25)
    Study= models.OneToOneField(Study)

Answer 1

试试这个，它应该在Test对象创建过程中只创建一次System对象：

class Test(models.Model):
    nameS= models.CharField(max_length=40)
    def save(self, *args, **kwargs):
        if not self.pk: # the object doesn't have PK until the very first save
            super(Test, self).save(*args, **kwargs)
            Test2.objects.create(test=self)
        else:
            super(Test, self).save(*args, **kwargs)

您可能还需要填充field1字段，因为根据您当前的设置它不能为NULL。

Answer 2

您可以使用pre_save信号：

# models.py
from django.db.models import pre_save
from django.dispatch import receiver

@receiver(pre_save, sender=Study)
def system_creator(**kwargs):
    created = kwargs.get('created')
    # flag `True` if object created now
    if created:
        study = kwargs.get('instance')
        test = Test.objects.create(Study=study,...)

Django创建对象

2 个答案: