python - Django post_save 接收器不会保存外键

Question

我有三个模型:User(来自django.contrib.auth.models)、UserProfile和GameCharacter >.

我设置了以下接收器，以便在创建User时，也会自动创建UserProfile和GameCharacter。

@receiver(models.signals.post_save, sender=User)
def create_user_profile(sender, instance, created, *args, **kwargs):
    if created:
        user_profile = UserProfile()
        user_profile.user = instance
        user_profile.money = 0

        user_profile.save()


@receiver(models.signals.post_save, sender=UserProfile)
def create_user_profile_character(sender, instance, created, *args, **kwargs):
    if created:
        instance.character = GameCharacter()  # Doesn't work, `character_id` is NULL in databse
        instance.character.save()
        instance.save()

正如预期的那样，它在数据库中创建了两个条目，一个 UserProfile 和一个 GameCharacter，但是 GameCharacter 的外键 未 保存，数据库中为NULL。

就好像 instance.character = GameCharacter() 行不存在。

我的模型:

class GameCharacter(models.Model):
    nickname = models.CharField(max_length=255, null=True, blank=True, default=None)
    server = models.ForeignKey(GameServer, on_delete=models.PROTECT, null=True, blank=True, default=None)
    is_bot = models.BooleanField(default=False)
    position = models.CharField(max_length=255, null=True, blank=True, default=None)

class UserProfile(models.Model):
    user = models.OneToOneField(User, on_delete=models.CASCADE, related_name='profile')
    character = models.ForeignKey(GameCharacter, null=True, blank=True, on_delete=models.SET_NULL)
    money = models.BigIntegerField()

我使用MySQL和InnoDB作为存储引擎。

有什么想法吗？

Answer 1

首先您必须创建一个 GameCharacter 对象。然后将其链接到instance.character

即:

character = GameCharacter()
character.save()
instance.character = character
instance.save()