Django中的非常独立的数据库中的“外键”
问题描述:
我写了一个使用两个不同数据库的Django站点。一个是本地的,我们称之为“Django”,这个数据库存储了来自标准安装的所有标准表 - auth,网站,评论等 - 以及一些额外的表格。Django中的非常独立的数据库中的“外键”
大部分数据(包括用户)来自另一台服务器上的数据库,我们称之为“传统”数据库。
我在寻找关于连接两个数据库的干净,pythonic方式的建议,特别是关于用户的。
我正在使用代理模型,该模型在我可以明确使用它的时候效果很好,但是当我作为相关对象访问用户对象时遇到了问题(例如,当使用内置的django评论系统)。
下面的代码是什么样子:
models.py:(指向Django的数据库)
from django.db import models
from django.conf import settings
from django.contrib.auth.models import User as AuthUser, UserManager as AuthUserManager, AnonymousUser as AuthAnonymousUser
class UserPerson(models.Model):
user = models.OneToOneField(AuthUser, related_name="person")
person_id = models.PositiveIntegerField(verbose_name='Legacy ID')
def __unicode__(self):
return "%s" % self.get_person()
def get_person(self):
if not hasattr(self, '_person'):
from legacy_models import Person
from utils import get_person_model
Person = get_person_model() or Person
self._person = Person.objects.get(pk=self.person_id)
return self._person
person=property(get_person)
class UserManager(AuthUserManager):
def get_for_id(self, id):
return self.get(person__person_id=id)
def get_for_email(self, email):
try:
person = Person.objects.get(email=email)
return self.get_for_id(person.pk)
except Person.DoesNotExist:
return User.DoesNotExist
def create_user(self, username, email, password=None, *args, **kwargs):
user = super(UserManager,self).create_user(username, email, password, *args, **kwargs)
try:
person_id = Person.objects.get(email=email).pk
userperson, created = UserPerson.objects.get_or_create(user=user, person_id=person_id)
except Person.DoesNotExist:
pass
return user
class AnonymousUser(AuthAnonymousUser):
class Meta:
proxy = True
class User(AuthUser):
class Meta:
proxy=True
def get_profile(self):
"""
Returns the Person record from the legacy database
"""
if not hasattr(self, '_profile_cache'):
self._profile_cache = UserPerson.objects.get(user=self).person
return self._profile_cache
objects = UserManager()
legacy_models.py:(指向 “遗产” 数据库)
class Person(models.Model):
id = models.AutoField(primary_key=True, db_column='PeopleID') # Field name made lowercase.
code = models.CharField(max_length=40, blank=True, db_column="person_code", unique=True)
first_name = models.CharField(max_length=50, db_column='firstName', blank=True) # Field name made lowercase.
last_name = models.CharField(max_length=50, db_column='lastName', blank=True) # Field name made lowercase.
email = models.CharField(max_length=255, blank=True)
def __unicode__(self):
return "%s %s" % (self.first_name, self.last_name)
def get_user(self):
from models import User
if not hasattr(self,'_user'):
self._user = User.objects.get_for_id(self.pk)
return self._user
user = property(get_user)
class Meta:
db_table = u'People'
我也掀起了自己的中间件,所以request.user
是pr氧还User
对象也。
真正的问题是,当我使用的东西有用户作为相关的对象,特别是在我有更少的控制模板。
在模板:
{{ request.user.get_profile }}
{# this works and returns the related Person object for the user #}
{% for comment in comments %} {# retrieved using the built-in comments app %}
{{ comment.user.get_profile }}
{# this throws an error because AUTH_PROFILE_MODULE is not defined by design #}
{% endfor %}
短创建它使用我的代理用户模型取而代之的,是有什么事我可以做评论系统的包装版本的?
答
下面是我解决它的方法。我完全停止使用用户代理。
models.py:
from django.db import models
from legacy_models import Person
from django.contrib.auth.models import User
class UserPerson(models.Model):
user = models.OneToOneField(User, related_name="person")
person_id = models.PositiveIntegerField(verbose_name='PeopleID', help_text='ID in the Legacy Login system.')
def __unicode__(self):
return "%s" % self.get_person()
def get_person(self):
if not hasattr(self, '_person'):
self._person = Person.objects.get(pk=self.person_id)
return self._person
person=property(get_person)
class LegacyPersonQuerySet(models.query.QuerySet):
def get(self, *args, **kwargs):
person_id = UserPerson.objects.get(*args, **kwargs).person_id
return LegacyPerson.objects.get(pk=person_id)
class LegacyPersonManager(models.Manager):
def get_query_set(self, *args, **kwargs):
return LegacyPersonQuerySet(*args, **kwargs)
class LegacyPerson(Person):
objects = LegacyPersonManager()
class Meta:
proxy=True
和legacy_models.py:
class Person(models.Model):
id = models.AutoField(primary_key=True, db_column='PeopleID') # Field name made lowercase.
code = models.CharField(max_length=40, blank=True, db_column="person_code", unique=True)
first_name = models.CharField(max_length=50, db_column='firstName', blank=True) # Field name made lowercase.
last_name = models.CharField(max_length=50, db_column='lastName', blank=True) # Field name made lowercase.
email = models.CharField(max_length=255, blank=True)
def __unicode__(self):
return "%s %s" % (self.first_name, self.last_name)
def get_user(self):
from models import User
if not hasattr(self,'_user'):
self._user = User.objects.get_for_id(self.pk)
return self._user
def set_user(self, user=None):
self._user=user
user = property(get_user, set_user)
class Meta:
db_table = u'People'
最后,在settings.py:
AUTH_PROFILE_MODULE = 'myauth.LegacyPerson'
这是一个更简单的解决方案,但至少可以工作!这意味着只要我需要传统记录,我必须拨打user_profile
,这意味着每个用户记录都有一个额外的查询,但这是一个公平的折衷,因为实际上我不太可能会这样做经常交叉检查。