【Django】模型层开发之重写模型类

在Django模型层开发中，我们可能会碰到这样的场景：django内置的数据表已经包含了用户数据表，但是其中并不包含我们想要的数据项，那么这时候有两种选择，要么重写用户信息模型类要么重新编写一个新的用户信息模型类，若选择重新编写，那么在数据库中将出现两个用户信息类，信息冗余且浪费资源。
Django内置的用户模型类源码如下所示：

class AbstractUser(AbstractBaseUser, PermissionsMixin):
    """
    An abstract base class implementing a fully featured User model with
    admin-compliant permissions.

    Username and password are required. Other fields are optional.
    """
    username_validator = UnicodeUsernameValidator()

    username = models.CharField(
        _('username'),
        max_length=150,
        unique=True,
        help_text=_('Required. 150 characters or fewer. Letters, digits and @/./+/-/_ only.'),
        validators=[username_validator],
        error_messages={
            'unique': _("A user with that username already exists."),
        },
    )
    first_name = models.CharField(_('first name'), max_length=150, blank=True)
    last_name = models.CharField(_('last name'), max_length=150, blank=True)
    email = models.EmailField(_('email address'), blank=True)
    is_staff = models.BooleanField(
        _('staff status'),
        default=False,
        help_text=_('Designates whether the user can log into this admin site.'),
    )
    is_active = models.BooleanField(
        _('active'),
        default=True,
        help_text=_(
            'Designates whether this user should be treated as active. '
            'Unselect this instead of deleting accounts.'
        ),
    )
    date_joined = models.DateTimeField(_('date joined'), default=timezone.now)

    objects = UserManager()

    EMAIL_FIELD = 'email'
    USERNAME_FIELD = 'username'
    REQUIRED_FIELDS = ['email']

    class Meta:
		......

可以清晰地看到不包含我们实际开发中需要的用户昵称、性别等数据项，因此我们继承于该类，向其中添加我们所需要的数据列：

1. 重写USER模型类

由于是重写用户数据类因此要继承于AbstractUser类，而不是models.Model类。

# models.py

from django.db import models
from django.contrib.auth.models import AbstractUser


GENDER_CHOICES = (
    ("male", "男"),
    ("famale", "女")
)


class UserProfile(AbstractUser):
    """
    重写用户模型类，继承自 AbstractUser
    """
    nick_name = models.CharField(max_length=50, verbose_name="昵称", default="")
    birthday = models.DateField(verbose_name="生日", null=True, blank=True)
    gender = models.CharField(verbose_name="性别", choices=GENDER_CHOICES, max_length=6)
    address = models.CharField(max_length=100, verbose_name="地址", default="")
    mobile = models.CharField(max_length=11, unique=True, verbose_name="电话号码")
    image = models.ImageField(upload_to="head_image/%Y%m", default="default.jpg")

    class Meta:
        """
        对当前表进行相关设置
        """
        verbose_name = "用户信息"
        verbose_name_plural = verbose_name

    def __str__(self):
        """返回一个对象的描述信息"""
        if self.nick_name:
            return self.nick_name
        else:
            return self.username

2. 在setting.py文件中设置重写的用户模型类位置

AUTH_USER_MODEL 参数格式为：app名.类名，而不是模块名.类名或包名.模块名.类名。

AUTH_USER_MODEL = "user.UserProfile"