Wie können Sie Entscheidungen basierend auf dem Modell treffen? - Modelle sind noch nicht geladen. FK-Problem (scheint zu sein)

Question

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# admindivisions.models 
class Countries(models.Model): 
    osm_id = models.IntegerField(db_index=True, null=True) 
    status = models.IntegerField() 
    population = models.IntegerField(null=True) 

    iso3166_1 = models.CharField(max_length=2, blank=True) 
    iso3166_1_a2 = models.CharField(max_length=2, blank=True) 
    iso3166_1_a3 = models.CharField(max_length=3, blank=True) 

    class Meta: 
     db_table = 'admindivisions_countries' 
     verbose_name = 'Country' 
     verbose_name_plural = 'Countries' 

class CountriesTranslations(models.Model): 
    common_name = models.CharField(max_length=81, blank=True, db_index=True) 
    formal_name = models.CharField(max_length=100, blank=True) 

    country = models.ForeignKey(Countries, on_delete=models.CASCADE, verbose_name='Details of Country') 
    lang_group = models.ForeignKey(LanguagesGroups, on_delete=models.CASCADE, verbose_name='Language of Country', 
            null=True) 

    class Meta: 
     db_table = 'admindivisions_countries_translations' 
     verbose_name = 'Country Translation' 
     verbose_name_plural = 'Countries Translations' 

# profiles.models 
from admindivisions.models import CountriesTranslations, Countries 

class AbstractProfile(models.Model): 
    COUNTRY_CHOICES =() 

    if (Languages.objects.model._meta.db_table in connection.introspection.table_names()): 
     # Just for test - This executes without any errors 
     CountriesTranslations.objects.filter(common_name="USA") 

     for country in Countries.objects.filter(status=1).exclude(iso3166_1='', iso3166_1_a2=''): 
      # Just for test - Also executes ok 
      CountriesTranslations.objects.get(common_name="USA") 

      # Makes problem (seems to be because of FK)     
      country_name = CountriesTranslations.objects.get(country=country) 
      COUNTRY_CHOICES += ((country.id, country_name),) 

    country = models.ForeignKey(Countries, verbose_name=_('country'), choices=COUNTRY_CHOICES, blank=True) 
    title = models.CharField(_('title'), max_length=30) 
    info = models.TextField(_('information'), max_length=500, blank=True) 

    class Meta: 
     abstract = True 

Traceback:

Traceback (most recent call last): 
    File "./manage.py", line 22, in <module> 
    execute_from_command_line(sys.argv) 
    File "/home/antonio/www/sportland/lib/python3.5/site-packages/django/core/management/__init__.py", line 367, in execute_from_command_line 
    utility.execute() 
    File "/home/antonio/www/sportland/lib/python3.5/site-packages/django/core/management/__init__.py", line 341, in execute 
    django.setup() 
    File "/home/antonio/www/sportland/lib/python3.5/site-packages/django/__init__.py", line 27, in setup 
    apps.populate(settings.INSTALLED_APPS) 
    File "/home/antonio/www/sportland/lib/python3.5/site-packages/django/apps/registry.py", line 108, in populate 
    app_config.import_models(all_models) 
    File "/home/antonio/www/sportland/lib/python3.5/site-packages/django/apps/config.py", line 199, in import_models 
    self.models_module = import_module(models_module_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/antonio/www/sportland/sportland/src/profiles/models.py", line 76, in <module> 
    class AbstractProfile(models.Model): 
    File "/home/antonio/www/sportland/sportland/src/profiles/models.py", line 109, in AbstractProfile 
    country_name = CountriesTranslations.objects.get(country=country) 
    File "/home/antonio/www/sportland/lib/python3.5/site-packages/django/db/models/manager.py", line 85, in manager_method 
    return getattr(self.get_queryset(), name)(*args, **kwargs) 
    File "/home/antonio/www/sportland/lib/python3.5/site-packages/django/db/models/query.py", line 376, in get 
    clone = self.filter(*args, **kwargs) 
    File "/home/antonio/www/sportland/lib/python3.5/site-packages/django/db/models/query.py", line 796, in filter 
    return self._filter_or_exclude(False, *args, **kwargs) 
    File "/home/antonio/www/sportland/lib/python3.5/site-packages/django/db/models/query.py", line 814, in _filter_or_exclude 
    clone.query.add_q(Q(*args, **kwargs)) 
    File "/home/antonio/www/sportland/lib/python3.5/site-packages/django/db/models/sql/query.py", line 1227, in add_q 
    clause, _ = self._add_q(q_object, self.used_aliases) 
    File "/home/antonio/www/sportland/lib/python3.5/site-packages/django/db/models/sql/query.py", line 1253, in _add_q 
    allow_joins=allow_joins, split_subq=split_subq, 
    File "/home/antonio/www/sportland/lib/python3.5/site-packages/django/db/models/sql/query.py", line 1133, in build_filter 
    lookups, parts, reffed_expression = self.solve_lookup_type(arg) 
    File "/home/antonio/www/sportland/lib/python3.5/site-packages/django/db/models/sql/query.py", line 1019, in solve_lookup_type 
    _, field, _, lookup_parts = self.names_to_path(lookup_splitted, self.get_meta()) 
    File "/home/antonio/www/sportland/lib/python3.5/site-packages/django/db/models/sql/query.py", line 1308, in names_to_path 
    if field.is_relation and not field.related_model: 
    File "/home/antonio/www/sportland/lib/python3.5/site-packages/django/utils/functional.py", line 35, in __get__ 
    res = instance.__dict__[self.name] = self.func(instance) 
    File "/home/antonio/www/sportland/lib/python3.5/site-packages/django/db/models/fields/related.py", line 111, in related_model 
    apps.check_models_ready() 
    File "/home/antonio/www/sportland/lib/python3.5/site-packages/django/apps/registry.py", line 131, in check_models_ready 
    raise AppRegistryNotReady("Models aren't loaded yet.") 
django.core.exceptions.AppRegistryNotReady: Models aren't loaded yet. 

Dies geschieht, wenn ich irgendwelche manage.py s Befehl ausgeführt werden soll.

Aus wenigen Tests oben kann ich erraten, dass das Problem auf ForeignKey zurückzuführen ist. Wie man es repariert?

Django 1.10

Answer 1

Sie müssen nicht wie die in den Klassen jede Logik tun. Offensichtlich können Sie die Modelle nicht abfragen, bis sie alle vollständig geladen sind.

Ich verstehe nicht, was Sie dort zu tun versuchen, aber Sie sollten es in eine Methode verschieben.