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问题描述
假设我有一个关系类,例如: class Friendship(models.Model): person1 = models.ForeignKey(Person,related_name ='person1') person2 = models.ForeignKey(Person,related_name ='person2')
所以我想使该对象对于一对 Person s是唯一的。如果我只是简单地做 unique_together =(( person1, person2),),那么我可以得到两个 Friendship
FS1.person1 = A,FS1.person2 = B FS2.person1 = B,FS2的对象.person2 = A我不想要这个。我想要两个人之间独特的友谊对象。那么,如何确保任何一对 Person s最多有一个 Friendship 对象?
谢谢!
解决方案我建议您使用model.clean方法:
class Friendship(models.Model): person1 = models.ForeignKey(Person,related_name ='person1') person2 =模型。ForeignKey(Person,related_name ='person2') def clean(self): direct = FriendShip.objects.filter(person1 = self.person1, person2 = self.person2)反向= FriendShip.objects.filter(person1 = self.person2,person2 = self.person1) 如果是direct.exists()或reverse.exists() :提高ValidationError({'key':'Message')})
Let's say I have a relationship class such as:
class Friendship(models.Model): person1 = models.ForeignKey(Person, related_name='person1') person2 = models.ForeignKey(Person, related_name='person2')so I want to make this object unique for a pair of Persons. If I simply do unique_together = (("person1", "person2"),) then I can end up with two Friendship objects where
FS1.person1 = A, FS1.person2 = B FS2.person1 = B, FS2.person2 = AI do not want this. I want a unique friendship object between two people. So how can I ensure that there is -at most- one Friendship object for any pair of Persons?
Thanks !
解决方案I suggest you to use model.clean method:
class Friendship(models.Model): person1 = models.ForeignKey(Person, related_name='person1') person2 = models.ForeignKey(Person, related_name='person2') def clean(self): direct = FriendShip.objects.filter(person1 = self.person1, person2 = self.person2) reverse = FriendShip.objects.filter(person1 = self.person2, person2 = self.person1) if direct.exists() or reverse.exists(): raise ValidationError({'key':'Message')})
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如何使相同模型的两个外键一起唯一?
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