django return Database.Cursor.execute(self, query, params) django.db.utils.OperationalError: no such table:答案

【问题标题】：django return Database.Cursor.execute(self, query, params) django.db.utils.OperationalError: no such table:django return Database.Cursor.execute(self, query, params) django.db.utils.OperationalError: no such table:
【发布时间】：2021-01-16 07:47:04
【问题描述】：

我有一个简单的模型类如下

class Language(models.Model):
    name= models.CharField(max_length=20)
    code= models.CharField(max_length=5)
    status=models.BooleanField()
    create_at=models.DateTimeField(auto_now_add=True)
    update_at=models.DateTimeField(auto_now=True)

    def __str__(self):
        return self.name

我想这样使用它

llist = Language.objects.filter()
list1 = []
for rs in llist:
    list1.append((rs.code,rs.name))
langlist = (list1)

但是当我尝试使用 llist 时它一直抛出这个错误：

return Database.Cursor.execute(self, query, params)
django.db.utils.OperationalError: no such table: home_language

我尝试使用python manage.py shell 进行查询，它显示与上述相同的错误。

这是完整的错误：

Traceback (most recent call last):
  File "C:\Users\Daisy\Downloads\Django-E-Commerce-master\env\lib\site-packages\django\db\backends\utils.py", line 86, in _execute
    return self.cursor.execute(sql, params)
  File "C:\Users\Daisy\Downloads\Django-E-Commerce-master\env\lib\site-packages\django\db\backends\sqlite3\base.py", line 396, in execute
    return Database.Cursor.execute(self, query, params)
sqlite3.OperationalError: no such table: home_language

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

Traceback (most recent call last):
  File "manage.py", line 21, in <module>
    main()
  File "manage.py", line 17, in main
    execute_from_command_line(sys.argv)
  File "C:\Users\Daisy\Downloads\Django-E-Commerce-master\env\lib\site-packages\django\core\management\__init__.py", line 401, in execute_from_command_line
    utility.execute()
  File "C:\Users\Daisy\Downloads\Django-E-Commerce-master\env\lib\site-packages\django\core\management\__init__.py", line 377, in execute
    django.setup()
  File "C:\Users\Daisy\Downloads\Django-E-Commerce-master\env\lib\site-packages\django\__init__.py", line 24, in setup
    apps.populate(settings.INSTALLED_APPS)
  File "C:\Users\Daisy\Downloads\Django-E-Commerce-master\env\lib\site-packages\django\apps\registry.py", line 114, in populate
    app_config.import_models()
  File "C:\Users\Daisy\Downloads\Django-E-Commerce-master\env\lib\site-packages\django\apps\config.py", line 211, in import_models
    self.models_module = import_module(models_module_name)
  File "c:\users\daisy\appdata\local\programs\python\python38\lib\importlib\__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1014, in _gcd_import
  File "<frozen importlib._bootstrap>", line 991, in _find_and_load
  File "<frozen importlib._bootstrap>", line 975, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 671, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 783, in exec_module
  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
  File "C:\Users\Daisy\OneDrive\Documents\Work\django\prjs\funnystore\mysite\home\models.py", line 29, in <module>
    for rs in llist:
  File "C:\Users\Daisy\Downloads\Django-E-Commerce-master\env\lib\site-packages\django\db\models\query.py", line 276, in __iter__
    self._fetch_all()
  File "C:\Users\Daisy\Downloads\Django-E-Commerce-master\env\lib\site-packages\django\db\models\query.py", line 1261, in _fetch_all
    self._result_cache = list(self._iterable_class(self))
  File "C:\Users\Daisy\Downloads\Django-E-Commerce-master\env\lib\site-packages\django\db\models\query.py", line 57, in __iter__
    results = compiler.execute_sql(chunked_fetch=self.chunked_fetch, chunk_size=self.chunk_size)
  File "C:\Users\Daisy\Downloads\Django-E-Commerce-master\env\lib\site-packages\django\db\models\sql\compiler.py", line 1152, in execute_sql
    cursor.execute(sql, params)
  File "C:\Users\Daisy\Downloads\Django-E-Commerce-master\env\lib\site-packages\django\db\backends\utils.py", line 100, in execute
    return super().execute(sql, params)
  File "C:\Users\Daisy\Downloads\Django-E-Commerce-master\env\lib\site-packages\django\db\backends\utils.py", line 68, in execute
    return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
  File "C:\Users\Daisy\Downloads\Django-E-Commerce-master\env\lib\site-packages\django\db\backends\utils.py", line 77, in _execute_with_wrappers
    return executor(sql, params, many, context)
  File "C:\Users\Daisy\Downloads\Django-E-Commerce-master\env\lib\site-packages\django\db\backends\utils.py", line 86, in _execute
    return self.cursor.execute(sql, params)
  File "C:\Users\Daisy\Downloads\Django-E-Commerce-master\env\lib\site-packages\django\db\utils.py", line 90, in __exit__
    raise dj_exc_value.with_traceback(traceback) from exc_value
  File "C:\Users\Daisy\Downloads\Django-E-Commerce-master\env\lib\site-packages\django\db\backends\utils.py", line 86, in _execute
    return self.cursor.execute(sql, params)
  File "C:\Users\Daisy\Downloads\Django-E-Commerce-master\env\lib\site-packages\django\db\backends\sqlite3\base.py", line 396, in execute
    return Database.Cursor.execute(self, query, params)
django.db.utils.OperationalError: no such table: home_language

【问题讨论】：

对于尚未进行任何迁移的新应用，您需要将应用名称传递给 makemigrations 以创建初始迁移文件：python manage.py makemigrations home。然后运行python manage.py migrate
尝试将类名更改为language，然后使用llist = language.objects.filter()，也不要忘记再次makemigrations和migrate
我尝试了上面的建议，但是这个错误发生在迁移之前，所以它不起作用
@Knight“这个错误发生在迁移之前”：你的意思是你在尝试创建迁移时遇到错误吗？如果是这样，您需要移动此代码，使其不会在您的应用启动时执行
@Knight 此代码在您的 models.py 文件中，在加载文件时执行查询，迁移将加载导致错误的文件。从您的 models.py 中删除代码，您应该能够迁移。为什么它首先位于该文件的根目录中？

标签： django database

【解决方案1】：

在命令提示符下使用此代码：

python manage.py migrate --run-syncdb

这对我有用……..

【讨论】：

请在您的回答中提供更多详细信息。正如目前所写的那样，很难理解您的解决方案。

【解决方案2】：

我将迁移用于特定应用，在您的情况下是：

python3 manage.py makemigrations home
python3 manage.py migrate

【讨论】：

【解决方案3】：

您应该使用以下方法进行迁移并迁移数据库：

python manage.py makemigrations
python manage.py migrate

【讨论】：

【解决方案4】：

在我的情况下，通过提前通过管理面板删除数据解决了错误。那么：

python manage.py makemigrations
python manage.py migrate

【讨论】：

【解决方案5】：

如果您在任何情况下使用此模型（home_language），请从您的所有代码中删除它，然后迁移它：

python3 manage.py makemigrations
python3 manage.py migrate

我希望它应该工作。

【讨论】：