将ForeignKey映射到另一个类

Question

This is my Django Models.py

class Test1(models.Model):
    id = models.AutoField(db_column='Id', primary_key=True)  
    name = models.TextField(db_column='Name', blank=True, null=True)  

class Test2(models.Model):
    id = models.AutoField(db_column='Id', primary_key=True) 
    sequence = models.IntegerField(db_column='Sequence') 
    test1id = models.ForeignKey('Test1', models.DO_NOTHING,null=False, db_column='Test1Id')

what i am trying to do is to ensure when the Test1 id is saved, it automatically fills in the test1id.

Answer 1

Not sure what you want to do here, but if you want to implement any post save actions for model look at django signals . Particularly at post_save signal.

Here is example usage of post_save signal, for model Test1 (suppose you want to create new Test2 object):

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

@receiver(post_save, sender=Test1)
def create_test2(sender, instance, created, **kwargs):
    Test2.objects.create(test1id=instance)

Answer 2

You can redefine the save method:

def save(self, **kwargs):
    if self.pk is None:
        super(Test1, self).save()
        Test2.objects.create(test1id=self)
    else:
        super(Test1, self).save()

So when you save Test1, a Test2 entry is created