Django 1.9 | 生产服务器上的makemigrations失败

Question

我正在开发一个Intranet Web应用程序，在我的开发环境中一切正常，但是当我尝试在服务器上部署项目并使用makemigrations启动数据库迁移时，出现了“ app.table不存在”的错误。

我面临的问题是，确实，该表不存在，因为它是第一次迁移，并且该错误显示在我的forms.py文件中。

我试过了：

- Deleting the app/migrations folder, didnt helped
- Executing "python manage.py migrate --fake", same result

而且我确实已经创建了数据库

编辑错误触发于

/path/to/my/project/app/forms.py, in class Meta:

编辑＃2

跟踪错误日志，似乎与project / project / urls.py有关。 我从app.form导入LoginForm和PasswordChange。 我认为这会在进行初始迁移之前触发对数据库的查询。

追溯

Traceback (most recent call last):
  File "manage.py", line 10, in <module>
    execute_from_command_line(sys.argv)
  File "/usr/lib/python2.7/site-packages/django/core/management/__init__.py", line 353, in execute_from_command_line
    utility.execute()
  File "/usr/lib/python2.7/site-packages/django/core/management/__init__.py", line 345, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/usr/lib/python2.7/site-packages/django/core/management/base.py", line 348, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/usr/lib/python2.7/site-packages/django/core/management/base.py", line 398, in execute
    self.check()
  File "/usr/lib/python2.7/site-packages/django/core/management/base.py", line 426, in check
    include_deployment_checks=include_deployment_checks,
  File "/usr/lib/python2.7/site-packages/django/core/checks/registry.py", line 75, in run_checks
    new_errors = check(app_configs=app_configs)
  File "/usr/lib/python2.7/site-packages/django/core/checks/urls.py", line 13, in check_url_config
    return check_resolver(resolver)
  File "/usr/lib/python2.7/site-packages/django/core/checks/urls.py", line 23, in check_resolver
    for pattern in resolver.url_patterns:
  File "/usr/lib/python2.7/site-packages/django/utils/functional.py", line 33, in __get__
    res = instance.__dict__[self.name] = self.func(instance)
  File "/usr/lib/python2.7/site-packages/django/core/urlresolvers.py", line 417, in url_patterns
    patterns = getattr(self.urlconf_module, "urlpatterns", self.urlconf_module)
  File "/usr/lib/python2.7/site-packages/django/utils/functional.py", line 33, in __get__
    res = instance.__dict__[self.name] = self.func(instance)
  File "/usr/lib/python2.7/site-packages/django/core/urlresolvers.py", line 410, in urlconf_module
    return import_module(self.urlconf_name)
  File "/usr/lib64/python2.7/importlib/__init__.py", line 37, in import_module
    __import__(name)
  File "/home/rortega/smce/smce/urls.py", line 20, in <module>
    from employeesControll.forms import LoginForm, PasswordChange
  File "/home/rortega/smce/employeesControll/forms.py", line 60, in <module>
    class employeesForm(forms.ModelForm):
  File "/home/rortega/smce/employeesControll/forms.py", line 61, in employeesForm
    class Meta:
  File "/home/rortega/smce/employeesControll/forms.py", line 96, in Meta
    'id_costCenter': forms.Select(choices=ccOptions, attrs={'class': 'form-control', 'name': 'id_costCenter'}),
  File "/usr/lib/python2.7/site-packages/django/forms/widgets.py", line 514, in __init__
    self.choices = list(choices)
  File "/usr/lib/python2.7/site-packages/django/db/models/query.py", line 258, in __iter__
    self._fetch_all()
  File "/usr/lib/python2.7/site-packages/django/db/models/query.py", line 1074, in _fetch_all
    self._result_cache = list(self.iterator())
  File "/usr/lib/python2.7/site-packages/django/db/models/query.py", line 128, in __iter__
    for row in compiler.results_iter():
  File "/usr/lib/python2.7/site-packages/django/db/models/sql/compiler.py", line 802, in results_iter
    results = self.execute_sql(MULTI)
  File "/usr/lib/python2.7/site-packages/django/db/models/sql/compiler.py", line 848, in execute_sql
    cursor.execute(sql, params)
  File "/usr/lib/python2.7/site-packages/django/db/backends/utils.py", line 79, in execute
    return super(CursorDebugWrapper, self).execute(sql, params)
  File "/usr/lib/python2.7/site-packages/django/db/backends/utils.py", line 64, in execute
    return self.cursor.execute(sql, params)
  File "/usr/lib/python2.7/site-packages/django/db/utils.py", line 95, in __exit__
    six.reraise(dj_exc_type, dj_exc_value, traceback)
  File "/usr/lib/python2.7/site-packages/django/db/backends/utils.py", line 64, in execute
    return self.cursor.execute(sql, params)
  File "/usr/lib/python2.7/site-packages/django/db/backends/mysql/base.py", line 112, in execute
    return self.cursor.execute(query, args)
  File "/usr/lib64/python2.7/site-packages/MySQLdb/cursors.py", line 226, in execute
    self.errorhandler(self, exc, value)
  File "/usr/lib64/python2.7/site-packages/MySQLdb/connections.py", line 36, in defaulterrorhandler
    raise errorvalue
django.db.utils.ProgrammingError: (1146, "Table 'smce_db.employeesControll_costcenter' doesn't exist")

Answer 1

我找不到任何“ pythonic”解决方案，但是我可以通过在views.py文件中注释我对forms.py的任何引用来解决迁移问题，如下所示：

class JobcodeCreate(CreateView):
    # form_class = jobcodeForm
    model = JobCode
    template_name = 'employeesControll/jobcode_create_form.html'
    success_url = reverse_lazy('jobcode-add')

并在导入这些表单时创建if语句：

import sys
if 'makemigrations' not in sys.argv and 'migrate' not in sys.argv:
    from .forms import (
        jobcodeForm,
        costcenterForm,
        employeesForm,
        employeesPersonalForm as form_EP,
        emergencyContactForm as form_EC
    )

我不知道这是唯一的还是最好的解决方案，但是只要它能正常工作，我就可以用它保持编码。

显然，这是1.9版本更新中的问题，因为自该版本以来，django会在进行迁移之前先加载urls.py，因此，如果加载了urls.py，还加载了views.py，并且如果您使用form_class自定义表单，forms.py尝试检查数据库时会出现此错误（我知道这很疯狂）。

Answer 2

使用--fake-initial可以防止Django在您首次尝试迁移时抱怨app.table不存在。

https://docs.djangoproject.com/en/1.10/topics/migrations/#initial-migrations