从Django 1.6升级到1.9：python manage.py迁移失败

Question

我在生产环境上运行Django
1.6.6，最近在登台（开发服务器）上升级到1.9.7。此更新是在服务器上执行的，我按照此处“从South升级”中概述的步骤进行操作。

我注意到迁移文件的结构已更改，并且不再包含create语句。这会引起问题，因为如果我从GitHub存储库中提取此新代码并运行python manage.py makemigrations或python manage.py migrate，它会说：

django.db.utils.OperationalError: no such table: appname_modelname

追溯指向我的urls.py，因为我在查询集中引用了模型：

queryset=list(chain(models.modelname.objects.filter(booleanField=True).order_by(object), models.aDifferentModel.objects.all())),

在1.9升级之前，已经syncdb为我创建了表，但是情况并非如此migrate。我也尝试过，python manage.py migrate --run-syncdb但这给出了相同的错误。

但是，如果我将SQLite数据库从生产或暂存环境复制到本地计算机并运行该命令，则该命令将起作用（因为该表已在数据库中）。

我是否必须手动创建这些表（尽管我假设不是），或者我做错了什么？

编辑：添加了代码段和回溯。很抱歉最初没有这样做。

models.py

class HowToApply(models.Model):
    title = models.CharField(max_length=500, blank=True, null=True)
    notice = models.TextField(blank=True, null=True)
description = models.TextField(blank=True, null=True)
active = models.BooleanField(default=None)
image = models.FileField(upload_to='numeric/img/%Y', blank=True, null=True)
mobile_image = models.FileField(upload_to='mobile/img/%Y', blank=True, null=True)
sequence_number = models.IntegerField(unique=True)

…

urls.py

from django.conf.urls import patterns, include, url
from django.views.generic import RedirectView, TemplateView, ListView, CreateView
from numeric import models, forms, views
from honeypot.decorators import check_honeypot
from numeric.views import CheckDeviceView
from itertools import chain

urlpatterns = patterns('',
    url(r'^academy/howtoapply/$',
        ListView.as_view(
            queryset =  list(chain(models.HowToApply.objects.filter(active=True).order_by('sequence_number'), models.AcademyAdmin.objects.all())),
        template_name = 'numeric/apply.html'
    ),
    name='apply'),

…

追溯

Traceback (most recent call last):
  File "manage.py", line 10, in <module>
    execute_from_command_line(sys.argv)
  File "/var/www/website_mig/venv/local/lib/python2.7/site-packages/django/core/management/__init__.py", line 350, in execute_from_command_line
    utility.execute()
  File "/var/www/website_mig/venv/local/lib/python2.7/site-packages/django/core/management/__init__.py", line 342, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/var/www/website_mig/venv/local/lib/python2.7/site-packages/django/core/management/base.py", line 348, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/var/www/website_mig/venv/local/lib/python2.7/site-packages/django/core/management/base.py", line 398, in execute
    self.check()
  File "/var/www/website_mig/venv/local/lib/python2.7/site-packages/django/core/management/base.py", line 426, in check
    include_deployment_checks=include_deployment_checks,
  File "/var/www/website_mig/venv/local/lib/python2.7/site-packages/django/core/checks/registry.py", line 75, in run_checks
    new_errors = check(app_configs=app_configs)
  File "/var/www/website_mig/venv/local/lib/python2.7/site-packages/django/core/checks/urls.py", line 10, in check_url_config
    return check_resolver(resolver)
  File "/var/www/website_mig/venv/local/lib/python2.7/site-packages/django/core/checks/urls.py", line 19, in check_resolver
    for pattern in resolver.url_patterns:
  File "/var/www/website_mig/venv/local/lib/python2.7/site-packages/django/utils/functional.py", line 33, in __get__
    res = instance.__dict__[self.name] = self.func(instance)
  File "/var/www/website_mig/venv/local/lib/python2.7/site-packages/django/core/urlresolvers.py", line 417, in url_patterns
    patterns = getattr(self.urlconf_module, "urlpatterns", self.urlconf_module)
  File "/var/www/website_mig/venv/local/lib/python2.7/site-packages/django/utils/functional.py", line 33, in __get__
    res = instance.__dict__[self.name] = self.func(instance)
  File "/var/www/website_mig/venv/local/lib/python2.7/site-packages/django/core/urlresolvers.py", line 410, in urlconf_module
    return import_module(self.urlconf_name)
  File "/usr/lib/python2.7/importlib/__init__.py", line 37, in import_module
    __import__(name)
  File "/var/www/website_mig/project/urls.py", line 14, in <module>
    (r'^', include('numeric.urls')),
  File "/var/www/website_mig/venv/local/lib/python2.7/site-packages/django/conf/urls/__init__.py", line 52, in include
    urlconf_module = import_module(urlconf_module)
  File "/usr/lib/python2.7/importlib/__init__.py", line 37, in import_module
    __import__(name)
  File "/var/www/website_mig/numeric/urls.py", line 144, in <module>
    queryset = list(chain(models.HowToApply.objects.filter(active=True).order_by('sequence_number'), models.AcademyAdmin.objects.all())),
  File "/var/www/website_mig/venv/local/lib/python2.7/site-packages/django/db/models/query.py", line 258, in __iter__
    self._fetch_all()
  File "/var/www/website_mig/venv/local/lib/python2.7/site-packages/django/db/models/query.py", line 1074, in _fetch_all
    self._result_cache = list(self.iterator())
  File "/var/www/website_mig/venv/local/lib/python2.7/site-packages/django/db/models/query.py", line 52, in __iter__
    results = compiler.execute_sql()
  File "/var/www/website_mig/venv/local/lib/python2.7/site-packages/django/db/models/sql/compiler.py", line 852, in execute_sql
    cursor.execute(sql, params)
  File "/var/www/website_mig/venv/local/lib/python2.7/site-packages/django/db/backends/utils.py", line 64, in execute
    return self.cursor.execute(sql, params)
  File "/var/www/website_mig/venv/local/lib/python2.7/site-packages/django/db/utils.py", line 95, in __exit__
    six.reraise(dj_exc_type, dj_exc_value, traceback)
  File "/var/www/website_mig/venv/local/lib/python2.7/site-packages/django/db/backends/utils.py", line 64, in execute
    return self.cursor.execute(sql, params)
  File "/var/www/website_mig/venv/local/lib/python2.7/site-packages/django/db/backends/sqlite3/base.py", line 323, in execute
    return Database.Cursor.execute(self, query, params)
django.db.utils.OperationalError: no such table: numeric_howtoapply`

Answer 1

问题是urls.py加载时正在评估您的查询集。当您makemigrations为新项目运行时，这会导致错误，因为尚未创建表。

您可以通过ListView将查询集子类化并将其移入来解决此问题get_queryset。

class MyListView(ListView):
    template_name = 'numeric/apply.html'

    def get_queryset(self):
        return list(chain(models.HowToApply.objects.filter(active=True).order_by('sequence_number'), models.AcademyAdmin.objects.all()))

然后更改您的网址格式以使用新视图。

url(r'^academy/howtoapply/$',
    MyListView.as_view(),
    name='apply',
),

Django 1.9运行一些检查以验证您的url模式，这意味着在makemigrations命令运行之前已加载url模式。Django
1.8没有这些检查，因此您可以像完成操作一样设置查询集。