使用 Django 在另一台服務器上創建 PostgreSQL 數據庫

Question

我有一個使用 Django 1.11 和在 Linux Mint 上運行的 PostgreSQL 10 數據庫的本地工作環境。

我正在嘗試復制此環境並將其安裝在兩台 Ubuntu 16.04 開發服務器上：一台用於 Web 服務器，另一台用於 SQL 服務器。

問題是在 Ubuntu PostgreSQL 服務器上運行 Django。

當我獲取 Django settings.py 文件，並將服務器從 'localhost' 更改為新 PostgreSQL 服務器的 IP 地址時，使用 manage.py 發出的每個命令都會失敗。 這包括 createsuperuser、makemigrations 和 migrate。 這在我的工作、開發機器和新的 Ubuntu Web 服務器上都失敗了。

在更改數據庫服務器之后和運行 manage.py 命令之前，我是否缺少應該完成的步驟？

我讀過的所有內容都說只需運行 makemigrations 和 migrate 命令。 我什至試圖刪除 makemigrations 文件夾，但仍然沒有運氣。

已驗證：可以使用相同的用戶 ID 和密碼遠程連接到新的 PostgreSQL 服務器，並且能夠創建表（因此問題應該與安全或遠程訪問無關）。

這是每次出現的錯誤：

            Traceback (most recent call last):
  File "/home/username/Documents/pycharm-2017.2.3/helpers/pycharm/django_manage.py", line 43, in <module>
    run_module(manage_file, None, '__main__', True)
  File "/usr/lib/python3.5/runpy.py", line 196, in run_module
    return _run_module_code(code, init_globals, run_name, mod_spec)
  File "/usr/lib/python3.5/runpy.py", line 96, in _run_module_code
    mod_name, mod_spec, pkg_name, script_name)
  File "/usr/lib/python3.5/runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "/home/dcripps/PycharmProjects/seamus/manage.py", line 22, in <module>
    execute_from_command_line(sys.argv)
  File "/home/dcripps/seamus_virt/lib/python3.5/site-packages/django/core/management/__init__.py", line 364, in execute_from_command_line
    utility.execute()
  File "/home/dcripps/seamus_virt/lib/python3.5/site-packages/django/core/management/__init__.py", line 356, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/home/dcripps/seamus_virt/lib/python3.5/site-packages/django/core/management/base.py", line 283, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/home/dcripps/seamus_virt/lib/python3.5/site-packages/django/core/management/base.py", line 327, in execute
    self.check()
  File "/home/dcripps/seamus_virt/lib/python3.5/site-packages/django/core/management/base.py", line 359, in check
    include_deployment_checks=include_deployment_checks,
  File "/home/dcripps/seamus_virt/lib/python3.5/site-packages/django/core/management/commands/migrate.py", line 62, in _run_checks
    issues.extend(super(Command, self)._run_checks(**kwargs))
  File "/home/dcripps/seamus_virt/lib/python3.5/site-packages/django/core/management/base.py", line 346, in _run_checks
    return checks.run_checks(**kwargs)
  File "/home/dcripps/seamus_virt/lib/python3.5/site-packages/django/core/checks/registry.py", line 81, in run_checks
    new_errors = check(app_configs=app_configs)
  File "/home/dcripps/seamus_virt/lib/python3.5/site-packages/django/core/checks/urls.py", line 16, in check_url_config
    return check_resolver(resolver)
  File "/home/dcripps/seamus_virt/lib/python3.5/site-packages/django/core/checks/urls.py", line 26, in check_resolver
    return check_method()
  File "/home/dcripps/seamus_virt/lib/python3.5/site-packages/django/urls/resolvers.py", line 254, in check
    for pattern in self.url_patterns:
  File "/home/dcripps/seamus_virt/lib/python3.5/site-packages/django/utils/functional.py", line 35, in __get__
    res = instance.__dict__[self.name] = self.func(instance)
  File "/home/dcripps/seamus_virt/lib/python3.5/site-packages/django/urls/resolvers.py", line 405, in url_patterns
    patterns = getattr(self.urlconf_module, "urlpatterns", self.urlconf_module)
  File "/home/dcripps/seamus_virt/lib/python3.5/site-packages/django/utils/functional.py", line 35, in __get__
    res = instance.__dict__[self.name] = self.func(instance)
  File "/home/dcripps/seamus_virt/lib/python3.5/site-packages/django/urls/resolvers.py", line 398, in urlconf_module
    return import_module(self.urlconf_name)
  File "/usr/lib/python3.5/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 986, in _gcd_import
  File "<frozen importlib._bootstrap>", line 969, in _find_and_load
  File "<frozen importlib._bootstrap>", line 958, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 673, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 665, in exec_module
  File "<frozen importlib._bootstrap>", line 222, in _call_with_frames_removed
  File "/home/dcripps/PycharmProjects/seamus/seamus/urls.py", line 21, in <module>
    from assessments import views as assessment_views
  File "/home/dcripps/PycharmProjects/seamus/assessments/views.py", line 10, in <module>
    from .forms import NewForm, CreateForm, DetailForm, EquipmentDetailForm, EquipmentAddForm, InspectionsForm, \
  File "/home/dcripps/PycharmProjects/seamus/assessments/forms.py", line 17, in <module>
    .values_list('item_number', 'number_type'))
  File "/home/dcripps/seamus_virt/lib/python3.5/site-packages/django/db/models/query.py", line 250, in __iter__
    self._fetch_all()
  File "/home/dcripps/seamus_virt/lib/python3.5/site-packages/django/db/models/query.py", line 1118, in _fetch_all
    self._result_cache = list(self._iterable_class(self))
  File "/home/dcripps/seamus_virt/lib/python3.5/site-packages/django/db/models/query.py", line 138, in __iter__
    for row in compiler.results_iter():
  File "/home/dcripps/seamus_virt/lib/python3.5/site-packages/django/db/models/sql/compiler.py", line 836, in results_iter
    results = self.execute_sql(MULTI)
  File "/home/dcripps/seamus_virt/lib/python3.5/site-packages/django/db/models/sql/compiler.py", line 894, in execute_sql
    raise original_exception
  File "/home/dcripps/seamus_virt/lib/python3.5/site-packages/django/db/models/sql/compiler.py", line 884, in execute_sql
    cursor.execute(sql, params)
  File "/home/dcripps/seamus_virt/lib/python3.5/site-packages/django/db/backends/utils.py", line 80, in execute
    return super(CursorDebugWrapper, self).execute(sql, params)
  File "/home/dcripps/seamus_virt/lib/python3.5/site-packages/django/db/backends/utils.py", line 65, in execute
    return self.cursor.execute(sql, params)
  File "/home/dcripps/seamus_virt/lib/python3.5/site-packages/django/db/utils.py", line 94, in __exit__
    six.reraise(dj_exc_type, dj_exc_value, traceback)
  File "/home/dcripps/seamus_virt/lib/python3.5/site-packages/django/utils/six.py", line 685, in reraise
    raise value.with_traceback(tb)
  File "/home/dcripps/seamus_virt/lib/python3.5/site-packages/django/db/backends/utils.py", line 65, in execute
    return self.cursor.execute(sql, params)
django.db.utils.ProgrammingError: relation "EquipmentTypes" does not exist
LINE 1: ...ntTypes"."equipment_type")) AS "number_type" FROM "Equipment..

謝謝你。

    Firewall on SQL Server:
    :~$ sudo ufw status
    Status: active
    To                         Action      From
    --                         ------      ----
    5432                       ALLOW       Anywhere  

這是我添加到 pg_hba.conf 文件中的內容：host all all 0.0.0.0/0 md5

settings.py 中的數據庫：

    DATABASES = {
        'default': {
            'ENGINE': 'django.db.backends.postgresql_psycopg2',
            'NAME': '******',
            'USER': '******',
            'PASSWORD': '******',
            'HOST': '192.168.1.221',
            'PORT': '5432',
        }

}

---

根據丹尼爾，錯誤來自這里：

item_number_list = [("", "---------")] + \
                   list(EquipmentTypes.objects.all()
                        .annotate(number_type=Concat('item_number', Value(' - '), 'equipment_type'))
                        .values_list('item_number', 'number_type'))

我使用它作為在模型中填充下拉列表的一種方式：

'item_number': forms.Select(choices=item_number_list, attrs={'class': 'form-control'}),

我注釋掉了這段代碼，一切都很完美。

Answer 1

回溯顯示問題是由評估/forms.py 的第 17 行引起的 - 我們看不到實際代碼，但您似乎是在類或模塊級別執行查詢。 您不能這樣做，因為該級別的任何內容都在導入時執行，這是在遷移有機會運行之前。

請注意，此問題與專門在單獨的服務器上運行數據庫無關，而只是由於移動到新的空數據庫而引起的。