Django＆Postgres：持續存在“ ProgrammingError：列不存在”

Question

我知道之前曾有人問過這個問題，但是我嘗試了答案中建議的所有內容，但似乎都沒有用。

問題：我的Django項目中有一個名為“ Accomm ”的模型類，其中存儲了許多對象。 在我嘗試檢索“ Accomm ”的一個或多個實例的網頁上，出現以下錯誤...

ProgrammingError at /
column objects_accomm.description does not exist
LINE 1: ...omm"."id", "objects_accomm"."mapped_location_id", "objects_a...

當我將新字段' description '遷移到' Accomm '模型時，開始出現此問題。

嘗試過的解決方案：我嘗試執行以下操作...清除所有Django遷移（使用--zero和--empty命令）； 清除數據庫（PostgreSQL 10）; 清除遷移和數據庫； 在Django項目settings.py文件中更改數據庫的名稱。 這些似乎都不起作用。 我在 這里和這里也都遵循了教程。

完整錯誤：

Django Version: 1.11.7
Python Version: 2.7.10
Installed Applications:
['django.contrib.admin',
 'django.contrib.auth',
 'django.contrib.contenttypes',
 'django.contrib.gis',
 'django.contrib.humanize',
 'django.contrib.messages',
 'django.contrib.sessions',
 'django.contrib.staticfiles',
 'rest_framework',
 'accounts',
 'maps',
 'objects',
 'social_django']
Installed Middleware:
['django.middleware.security.SecurityMiddleware',
 'django.contrib.sessions.middleware.SessionMiddleware',
 'django.middleware.common.CommonMiddleware',
 'django.middleware.csrf.CsrfViewMiddleware',
 'django.contrib.auth.middleware.AuthenticationMiddleware',
 'django.contrib.messages.middleware.MessageMiddleware',
 'django.middleware.clickjacking.XFrameOptionsMiddleware',
 'social_django.middleware.SocialAuthExceptionMiddleware']

Traceback:

    File "/Library/Python/2.7/site-packages/django/core/handlers/exception.py" in inner
      41.             response = get_response(request)

    File "/Library/Python/2.7/site-packages/django/core/handlers/base.py" in _get_response
      187.                 response = self.process_exception_by_middleware(e, request)

    File "/Library/Python/2.7/site-packages/django/core/handlers/base.py" in _get_response
      185.                 response = wrapped_callback(request, *callback_args, **callback_kwargs)

    File "/Users/jayt/project/main/views.py" in home
      21.     return render(request, 'home.html', {'accomm':accomm})

    File "/Library/Python/2.7/site-packages/django/shortcuts.py" in render
      30.     content = loader.render_to_string(template_name, context, request, using=using)

    File "/Library/Python/2.7/site-packages/django/template/loader.py" in render_to_string
      68.     return template.render(context, request)

    File "/Library/Python/2.7/site-packages/django/template/backends/django.py" in render
      66.             return self.template.render(context)

    File "/Library/Python/2.7/site-packages/django/template/base.py" in render
      207.                     return self._render(context)

    File "/Library/Python/2.7/site-packages/django/template/base.py" in _render
      199.         return self.nodelist.render(context)

    File "/Library/Python/2.7/site-packages/django/template/base.py" in render
      990.                 bit = node.render_annotated(context)

    File "/Library/Python/2.7/site-packages/django/template/base.py" in render_annotated
      957.             return self.render(context)

    File "/Library/Python/2.7/site-packages/django/template/loader_tags.py" in render
      177.             return compiled_parent._render(context)

    File "/Library/Python/2.7/site-packages/django/template/base.py" in _render
      199.         return self.nodelist.render(context)

    File "/Library/Python/2.7/site-packages/django/template/base.py" in render
      990.                 bit = node.render_annotated(context)

    File "/Library/Python/2.7/site-packages/django/template/base.py" in render_annotated
      957.             return self.render(context)

    File "/Library/Python/2.7/site-packages/django/template/loader_tags.py" in render
      72.                 result = block.nodelist.render(context)

    File "/Library/Python/2.7/site-packages/django/template/base.py" in render
      990.                 bit = node.render_annotated(context)

    File "/Library/Python/2.7/site-packages/django/template/base.py" in render_annotated
      957.             return self.render(context)

    File "/Library/Python/2.7/site-packages/django/template/defaulttags.py" in render
      321.             if match:

    File "/Library/Python/2.7/site-packages/django/db/models/query.py" in __nonzero__
      258.         return type(self).__bool__(self)

    File "/Library/Python/2.7/site-packages/django/db/models/query.py" in __bool__
      254.         self._fetch_all()

    File "/Library/Python/2.7/site-packages/django/db/models/query.py" in _fetch_all
      1118.             self._result_cache = list(self._iterable_class(self))

    File "/Library/Python/2.7/site-packages/django/db/models/query.py" in __iter__
      53.         results = compiler.execute_sql(chunked_fetch=self.chunked_fetch)

    File "/Library/Python/2.7/site-packages/django/db/models/sql/compiler.py" in execute_sql
      894.             raise original_exception

    Exception Type: ProgrammingError at /
    Exception Value: column objects_accomm.description does not exist
    LINE 1: ...omm"."id", "objects_accomm"."mapped_location_id", "objects_a...
                                                             ^

編輯： “ Accomm”的Models.py：

class Accomm(models.Model):
    mapped_location=models.ForeignKey(Location,related_name='l_accomms',null=True,blank=True,on_delete=models.SET_NULL)
    description=models.CharField(max_length=1000,null=True,blank=True)
    creator=models.OneToOneField(accountmodels.UserProfileModel,related_name='u_creator',null=True,on_delete=models.SET_NULL,blank=True)
    slug_key=models.SlugField(unique=True)
    is_active=models.BooleanField(default=False)

Views.py：

def home(request):
    user = request.user
    accomm = Accomm.objects.annotate(img_count=models.Count('a_image')).filter(img_count__gte=1)[:6]
    return render(request, 'home.html', {'accomm':accomm})

除了此處提出的解決方案外，還有其他想法嗎？

Answer 1

當我的遷移變得不穩定時，我喜歡嘗試的方法是：

python manage.py makemigrations
python manage.py migrate --fake

因此，這似乎使您的模型看起來像已添加了列，因此，從這里我將模型剪切並粘貼到臨時文件中，保存模型並定期運行遷移，這將刪除所有模型。 然后，將模型重新粘貼到models.py中，並再次運行遷移。 這似乎對我有用，也許有更好的方法來管理它，但是我對django還是比較陌生，因為我剛剛完成了我的第一個大項目。 真希望這對您有所幫助，如果不能讓我知道，我可能還會為您提供其他服務！