Question

我有以下型号，我正在django shell中尝试这两个命令：

from auth_lifecycle.models import UserProfile
UserProfile(user_id=2).birth_year

但它返回None，尽管UserProfile(user_id=2)返回<UserProfile: user>。

以下是确认数据存在的查询：

 auth_lifecycle_db=# select * from auth_lifecycle_userprofile;
  id | birth_year | user_id
 ----+------------+---------
   1 |       1905 |       1
   2 |       1910 |       2
 (2 rows)

如何访问birth_year属性？

models.py

"""Defines a single extra user-profile field for the user-authentication
    lifecycle demo project: Birth year
"""
from django.contrib.auth.models import User
from django.db                  import models


class UserProfile(models.Model):
    """Extra information about a user: Birth year and profile picture. See
        the package doc for more info.

        ---NOTES---

        Useful related SQL:
            - `select id from auth_user where username <> 'admin';`
            - `select * from auth_lifecycle_userprofile where user_id=(x,x,...);`
    """
    # This line is required. Links UserProfile to a User model instance.
    user = models.OneToOneField(User, related_name="profile")

    # The additional attributes we wish to include.
    birth_year = models.IntegerField(
        blank=True,
        verbose_name="Year you were born")

    # Override the __str__() method to return out something meaningful
    def __str__(self):
        return self.user.username

Answer 1

您需要使用objects属性来访问数据库值。

UserProfile.objects.get(user_id=2).birth_year

或

User.objects.get(id=2).profile.birth_year

您的所有代码都是使用UserProfile

创建user_id=2的本地实例

https://docs.djangoproject.com/en/1.7/topics/db/models/#model-attributes

UserProfile（user_id = 2）返回<userprofile：user =“”>，但UserProfile（user_id = 2）.birth_year返回None </userprofile：>

1 个答案: