django 模型的条件约束

Question

我有这样的数据库模型

ActionType = (
    (1,"PostBack"),
    (2,"Uri"),
)

class RichMenu(BaseModel):
    key = m.CharField(max_length=64,unique=True)
    action_type = m.IntegerField(choices=ActionType,default=1)
    url = m.CharField(max_length=255,blank=True,null=True)
    name = m.CharField(max_length=255,blank=True,null=True)

现在我想做出这样的约束，

• 当

  action_type

  为1时，

  url

  应为空，

  name

  不应为空

• 当

  action_type

  为2时，

  name

  应为空，

  url

  不应为空

是否可以对这种情况做条件约束？

Answer 1

您可以在将其保存到数据库之前将方法 save() 覆盖到有效字段

ActionType = (
    (1,"PostBack"),
    (2,"Uri"),
)

class RichMenu(BaseModel):
    key = m.CharField(max_length=64,unique=True)
    action_type = m.IntegerField(choices=ActionType,default=1)
    url = m.CharField(max_length=255,blank=True,null=True)
    name = m.CharField(max_length=255,blank=True,null=True)

    def save(self, *args, **kwargs):
        if self.action_type == 1:
            if self.url is not None and self.name is None:
                raise Exception("INVALID URL AND NAME")
        elif self.action_type == 2:
            if self.url is None and self.name is not None:
                raise Exception("INVALID URL AND NAME")
        super(RichMenu, self).save(*args, **kwargs)