Невозможно выполнить миграции - ... не имеет поля с именем «вопросы»

Question

Я пытаюсь понять, почему Django возвращает эту ошибку при попытке migrate после makemigrations. Я попытался изменить связанные имена и удалить последние миграции, но ничего не работает.

Возможно, вы видите, в чем проблема?

Ошибка после того, как мигрируют: django.core.exceptions.FieldDoesNotExist: LanguageQuizSitting has no field named 'questions'

Models.py

from django.db import models 
from SolutionsForLanguagesApp import models as sfl_models 
from jsonfield import JSONField 
import random 

class LanguageQuiz(models.Model): 
    name = models.CharField(max_length=40) 
    language = models.OneToOneField(sfl_models.Language) 


class Question(models.Model): 
    language_quiz = models.ForeignKey(LanguageQuiz,related_name='questions') 
    text = models.TextField() 

class Answer(models.Model): 
    question = models.ForeignKey(Question,related_name='answers') 
    text = models.TextField() 
    correct = models.BooleanField() 

class LanguageQuizSitting(models.Model): 
    user = models.OneToOneField(sfl_models.User) 
    quiz = models.OneToOneField(LanguageQuiz) 
    date_opened = models.DateTimeField(auto_created=True) 
    date_closed = models.DateTimeField(null=True) 
    max_questions = models.IntegerField() 

    def load_questions(self): 
     questions = random.sample(self.quiz.questions,self.max_questions) 
     for question in questions: 
      SittingQuestion.objects.create(question=question,sitting=self) 

    def get_next_question(self): 
     q = self.questions.filter(answered=0) 
     if len(q)>0: 
      return q[0] 
     else: 
      return False 

class SittingQuestion(models.Model): 
    sitting = models.ForeignKey(LanguageQuizSitting,related_name='questions',on_delete=models.CASCADE) 
    question = models.ForeignKey(Question, related_name='SittingQuestions') 
    answered = models.BooleanField(default=0) 
    result = models.BooleanField(default=0) 

ПОСЛЕДНИЙ МИГРАЦИЯ

class Migration(migrations.Migration): 

    dependencies = [ 
     ('language_tests', '0001_initial'), 
    ] 

    operations = [ 
     migrations.AlterField(
      model_name='question', 
      name='language_quiz', 
      field=models.ForeignKey(related_name='questions', to='language_tests.LanguageQuiz'), 
     ), 
     migrations.AlterField(
      model_name='sittingquestion', 
      name='question', 
      field=models.ForeignKey(related_name='sitting_questions', to='language_tests.Question'), 
     ), 
     migrations.AlterField(
      model_name='sittingquestion', 
      name='sitting', 
      field=models.ForeignKey(related_name='questions', to='language_tests.LanguageQuizSitting'), 
     ), 
    ] 

след вызовов TRACEBACK:

(venv) C:\Users\Milano\PycharmProjects\FutileStudio\SolutionsForLanguages_2>python manage.py migrate 
Operations to perform: 
    Synchronize unmigrated apps: essay, smart_selects, true_false, super_inlines, staticfiles, multichoice, messages, nested_inline, quiz, django_extensions, django_tables2, constance, crispy_forms 
    Apply all migrations: language_tests, database, admin, sessions, auth, contenttypes, SolutionsForLanguagesApp 
Synchronizing apps without migrations: 
    Creating tables... 
    Running deferred SQL... 
    Installing custom SQL... 
Running migrations: 
    Rendering model states... DONE 
    Applying language_tests.0002_auto_20160711_1524...Traceback (most recent call last): 
    File "manage.py", line 10, in <module> 
    execute_from_command_line(sys.argv) 
    File "C:\Users\Milano\PycharmProjects\FutileStudio\SolutionsForLanguages_2\venv\lib\site-packages\django\core\management\__init__.py", line 354, in execute_from_command_line 
    utility.execute() 
    File "C:\Users\Milano\PycharmProjects\FutileStudio\SolutionsForLanguages_2\venv\lib\site-packages\django\core\management\__init__.py", line 346, in execute 
    self.fetch_command(subcommand).run_from_argv(self.argv) 
    File "C:\Users\Milano\PycharmProjects\FutileStudio\SolutionsForLanguages_2\venv\lib\site-packages\django\core\management\base.py", line 394, in run_from_argv 
    self.execute(*args, **cmd_options) 
    File "C:\Users\Milano\PycharmProjects\FutileStudio\SolutionsForLanguages_2\venv\lib\site-packages\django\core\management\base.py", line 445, in execute 
    output = self.handle(*args, **options) 
    File "C:\Users\Milano\PycharmProjects\FutileStudio\SolutionsForLanguages_2\venv\lib\site-packages\django\core\management\commands\migrate.py", line 222, in handle 
    executor.migrate(targets, plan, fake=fake, fake_initial=fake_initial) 
    File "C:\Users\Milano\PycharmProjects\FutileStudio\SolutionsForLanguages_2\venv\lib\site-packages\django\db\migrations\executor.py", line 110, in migrate 
    self.apply_migration(states[migration], migration, fake=fake, fake_initial=fake_initial) 
    File "C:\Users\Milano\PycharmProjects\FutileStudio\SolutionsForLanguages_2\venv\lib\site-packages\django\db\migrations\executor.py", line 148, in apply_migration 
    state = migration.apply(state, schema_editor) 
    File "C:\Users\Milano\PycharmProjects\FutileStudio\SolutionsForLanguages_2\venv\lib\site-packages\django\db\migrations\migration.py", line 115, in apply 
    operation.database_forwards(self.app_label, schema_editor, old_state, project_state) 
    File "C:\Users\Milano\PycharmProjects\FutileStudio\SolutionsForLanguages_2\venv\lib\site-packages\django\db\migrations\operations\fields.py", line 201, in database_forwards 
    schema_editor.alter_field(from_model, from_field, to_field) 
    File "C:\Users\Milano\PycharmProjects\FutileStudio\SolutionsForLanguages_2\venv\lib\site-packages\django\db\backends\base\schema.py", line 484, in alter_field 
    old_db_params, new_db_params, strict) 
    File "C:\Users\Milano\PycharmProjects\FutileStudio\SolutionsForLanguages_2\venv\lib\site-packages\django\db\backends\sqlite3\schema.py", line 203, in _alter_field 
    self._remake_table(model, alter_fields=[(old_field, new_field)]) 
    File "C:\Users\Milano\PycharmProjects\FutileStudio\SolutionsForLanguages_2\venv\lib\site-packages\django\db\backends\sqlite3\schema.py", line 140, in _remake_table 
    self.create_model(temp_model) 
    File "C:\Users\Milano\PycharmProjects\FutileStudio\SolutionsForLanguages_2\venv\lib\site-packages\django\db\backends\base\schema.py", line 236, in create_model 
    definition, extra_params = self.column_sql(model, field) 
    File "C:\Users\Milano\PycharmProjects\FutileStudio\SolutionsForLanguages_2\venv\lib\site-packages\django\db\backends\base\schema.py", line 135, in column_sql 
    db_params = field.db_parameters(connection=self.connection) 
    File "C:\Users\Milano\PycharmProjects\FutileStudio\SolutionsForLanguages_2\venv\lib\site-packages\django\db\models\fields\related.py", line 2010, in db_parameters 
    return {"type": self.db_type(connection), "check": []} 
    File "C:\Users\Milano\PycharmProjects\FutileStudio\SolutionsForLanguages_2\venv\lib\site-packages\django\db\models\fields\related.py", line 2001, in db_type 
    rel_field = self.related_field 
    File "C:\Users\Milano\PycharmProjects\FutileStudio\SolutionsForLanguages_2\venv\lib\site-packages\django\db\models\fields\related.py", line 1904, in related_field 
    return self.foreign_related_fields[0] 
    File "C:\Users\Milano\PycharmProjects\FutileStudio\SolutionsForLanguages_2\venv\lib\site-packages\django\db\models\fields\related.py", line 1638, in foreign_related_fields 
    return tuple(rhs_field for lhs_field, rhs_field in self.related_fields if rhs_field) 
    File "C:\Users\Milano\PycharmProjects\FutileStudio\SolutionsForLanguages_2\venv\lib\site-packages\django\db\models\fields\related.py", line 1625, in related_fields 
    self._related_fields = self.resolve_related_fields() 
    File "C:\Users\Milano\PycharmProjects\FutileStudio\SolutionsForLanguages_2\venv\lib\site-packages\django\db\models\fields\related.py", line 1618, in resolve_related_fields 
    else self.rel.to._meta.get_field(to_field_name)) 
    File "C:\Users\Milano\PycharmProjects\FutileStudio\SolutionsForLanguages_2\venv\lib\site-packages\django\db\models\options.py", line 554, in get_field 
    raise FieldDoesNotExist('%s has no field named %r' % (self.object_name, field_name)) 
django.core.exceptions.FieldDoesNotExist: LanguageQuizSitting has no field named 'questions' 

Answer 1

Так дело заключается в следующем:

questions = random.sample(self.quiz.questions,self.max_questions) 

self.quiz туда:

quiz = models.OneToOneField(LanguageQuiz) 

и quiz.questions туда:

class LanguageQuiz(models.Model): 
    name = models.CharField(max_length=40) 
    language = models.OneToOneField(sfl_models.Language) 

дело вопросов не существует в LanguageQuiz.