メイクマイグレーション実行時のDjangoの関係エラー

Question

ちょっと新しいデータベースを初期化しようとしていますが、マイグレーションを設定する際に問題が発生しています。私が得ているエラーは、私のフォームを設定することによると思われる。私が使っている形で、私はそう選択フィールドを作成しています：

PROVINCE_CHOICESはここから来て

from django import forms 
from ..custom_admin import widgets, choices 


class MemberForm(forms.Form): 
    provinces = forms.ChoiceField(label='Provinces', choices=choices.PROVINCE_CHOICES, required=True) 

：

from ..base.models import ProvinceCode 

PROVINCE_CHOICES = [] 
for province in ProvinceCode.objects.filter(country_code_id=1).order_by('code'): 
    PROVINCE_CHOICES.append((province.code, province.code)) 

問題は、このループは、移行の前に呼び出されていることのようです州モデルが存在しないことを示すエラーが表示されます。このファイルへの参照をコメントアウトすることで、移行は機能しますが、引き続き使用するには実用的ではないようです。このエラーを回避する方法はありますか？

./manage.py makemigrations   
Traceback (most recent call last): 
    File "/Users/js/Documents/VirtualEnvironments/pcenv/lib/python3.5/site-packages/django/db/backends/utils.py", line 64, in execute 
    return self.cursor.execute(sql, params) 
psycopg2.ProgrammingError: relation "pc_psr_code" does not exist 
LINE 1: ...escription", "pc_psr_code"."country_code_id" FROM "pc_psr_co... 
                  ^


The above exception was the direct cause of the following exception: 

Traceback (most recent call last): 
    File "./manage.py", line 9, in <module> 
    django.setup() 
    File "/Users/js/Documents/VirtualEnvironments/pcenv/lib/python3.5/site-packages/django/__init__.py", line 18, in setup 
    apps.populate(settings.INSTALLED_APPS) 
    File "/Users/js/Documents/VirtualEnvironments/pcenv/lib/python3.5/site-packages/django/apps/registry.py", line 115, in populate 
    app_config.ready() 
    File "/Users/js/Documents/VirtualEnvironments/pcenv/lib/python3.5/site-packages/debug_toolbar/apps.py", line 15, in ready 
    dt_settings.patch_all() 
    File "/Users/js/Documents/VirtualEnvironments/pcenv/lib/python3.5/site-packages/debug_toolbar/settings.py", line 228, in patch_all 
    patch_root_urlconf() 
    File "/Users/js/Documents/VirtualEnvironments/pcenv/lib/python3.5/site-packages/debug_toolbar/settings.py", line 216, in patch_root_urlconf 
    reverse('djdt:render_panel') 
    File "/Users/js/Documents/VirtualEnvironments/pcenv/lib/python3.5/site-packages/django/core/urlresolvers.py", line 568, in reverse 
    app_list = resolver.app_dict[ns] 
    File "/Users/js/Documents/VirtualEnvironments/pcenv/lib/python3.5/site-packages/django/core/urlresolvers.py", line 360, in app_dict 
    self._populate() 
    File "/Users/js/Documents/VirtualEnvironments/pcenv/lib/python3.5/site-packages/django/core/urlresolvers.py", line 293, in _populate 
    for pattern in reversed(self.url_patterns): 
    File "/Users/js/Documents/VirtualEnvironments/pcenv/lib/python3.5/site-packages/django/utils/functional.py", line 33, in __get__ 
    res = instance.__dict__[self.name] = self.func(instance) 
    File "/Users/js/Documents/VirtualEnvironments/pcenv/lib/python3.5/site-packages/django/core/urlresolvers.py", line 417, in url_patterns 
    patterns = getattr(self.urlconf_module, "urlpatterns", self.urlconf_module) 
    File "/Users/js/Documents/VirtualEnvironments/pcenv/lib/python3.5/site-packages/django/utils/functional.py", line 33, in __get__ 
    res = instance.__dict__[self.name] = self.func(instance) 
    File "/Users/js/Documents/VirtualEnvironments/pcenv/lib/python3.5/site-packages/django/core/urlresolvers.py", line 410, in urlconf_module 
    return import_module(self.urlconf_name) 
    File "/Users/js/Documents/VirtualEnvironments/pcenv/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 662, in exec_module 
    File "<frozen importlib._bootstrap>", line 222, in _call_with_frames_removed 
    File "/Users/js/Documents/app/platform/test/pc/urls.py", line 7, in <module> 
    from .custom_admin import urls as custom_urls 
    File "/Users/js/Documents/app/platform/test/pc/custom_admin/urls.py", line 3, in <module> 
    from ..party import views as party_views 
    File "/Users/js/Documents/app/platform/test/pc/party/views.py", line 1, in <module> 
    from ..party import forms 
    File "/Users/js/Documents/app/platform/test/pc/party/forms.py", line 2, in <module> 
    from ..custom_admin import widgets, choices 
    File "/Users/js/Documents/app/platform/test/pc/custom_admin/choices.py", line 9, in <module> 
    for province in ProvinceCode.objects.filter(country_code_id=1).order_by('code'): 
    File "/Users/js/Documents/VirtualEnvironments/pcenv/lib/python3.5/site-packages/django/db/models/query.py", line 258, in __iter__ 
    self._fetch_all() 
    File "/Users/js/Documents/VirtualEnvironments/pcenv/lib/python3.5/site-packages/django/db/models/query.py", line 1074, in _fetch_all 
    self._result_cache = list(self.iterator()) 
    File "/Users/js/Documents/VirtualEnvironments/pcenv/lib/python3.5/site-packages/django/db/models/query.py", line 52, in __iter__ 
    results = compiler.execute_sql() 
    File "/Users/js/Documents/VirtualEnvironments/pcenv/lib/python3.5/site-packages/django/db/models/sql/compiler.py", line 848, in execute_sql 
    cursor.execute(sql, params) 
    File "/Users/js/Documents/VirtualEnvironments/pcenv/lib/python3.5/site-packages/django/db/backends/utils.py", line 79, in execute 
    return super(CursorDebugWrapper, self).execute(sql, params) 
    File "/Users/js/Documents/VirtualEnvironments/pcenv/lib/python3.5/site-packages/django/db/backends/utils.py", line 64, in execute 
    return self.cursor.execute(sql, params) 
    File "/Users/js/Documents/VirtualEnvironments/pcenv/lib/python3.5/site-packages/django/db/utils.py", line 95, in __exit__ 
    six.reraise(dj_exc_type, dj_exc_value, traceback) 
    File "/Users/js/Documents/VirtualEnvironments/pcenv/lib/python3.5/site-packages/django/utils/six.py", line 685, in reraise 
    raise value.with_traceback(tb) 
    File "/Users/js/Documents/VirtualEnvironments/pcenv/lib/python3.5/site-packages/django/db/backends/utils.py", line 64, in execute 
    return self.cursor.execute(sql, params) 
django.db.utils.ProgrammingError: relation "pc_psr_code" does not exist 
LINE 1: ...escription", "pc_psr_code"."country_code_id" FROM "pc_psr_co... 

省モデル：：あなたはアプリレジストリの初期化時にクエリを実行することはできません

class ProvinceCode(models.Model): 
    code = models.CharField(blank=False, null=False, unique=True) 
    country_code = models.ForeignKey('CountryCode', blank=False, null=True) 

Answer 1

を私はmanage.py makemigrationsを実行したときに

は参考のために、ここで私が取得エラーです。この間にchoices.pyファイルが間接的にインポートされ、エラーが発生します。この問題を修正するには、choicesに呼び出し可能に渡すことができます。

def get_provinces(): 
    province_choices = [] 
    for province in ProvinceCode.objects.filter(country_code_id=1).order_by('code'): 
     province_choices.append((province.code, province.code)) 
    return province_choices 

class MemberForm(forms.Form): 
    provinces = forms.ChoiceField(label='Provinces', choices=get_provinces, required=True)