将数据库同步到 python django答案

【问题标题】：sync database to python django将数据库同步到 python django
【发布时间】：2019-03-11 17:31:17
【问题描述】：

我正在尝试将 SQLite3 数据库连接到 Django。当我尝试使用命令同步数据库时

$ python manage.py syncdb

它显示了很长的痕迹。我不知道如何解决它。谁能帮我解决这个问题

Traceback (most recent call last):
  File "manage.py", line 15, in <module>
    execute_from_command_line(sys.argv)
  File "C:\Users\LENOVO\AppData\Local\Programs\Python\Python35\lib\site-packages\django\core\management\__init__.py", line 381, in execute_from_command_line
    utility.execute()
  File "C:\Users\LENOVO\AppData\Local\Programs\Python\Python35\lib\site-packages\django\core\management\__init__.py", line 357, in execute
    django.setup()
  File "C:\Users\LENOVO\AppData\Local\Programs\Python\Python35\lib\site-packages\django\__init__.py", line 24, in setup
    apps.populate(settings.INSTALLED_APPS)
  File "C:\Users\LENOVO\AppData\Local\Programs\Python\Python35\lib\site-packages\django\apps\registry.py", line 112, in populate
    app_config.import_models()
  File "C:\Users\LENOVO\AppData\Local\Programs\Python\Python35\lib\site-packages\django\apps\config.py", line 198, in import_models
    self.models_module = import_module(models_module_name)
  File "C:\Users\LENOVO\AppData\Local\Programs\Python\Python35\lib\importlib\__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 985, in _gcd_import
  File "<frozen importlib._bootstrap>", line 968, in _find_and_load
  File "<frozen importlib._bootstrap>", line 957, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 673, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 697, in exec_module
  File "<frozen importlib._bootstrap>", line 222, in _call_with_frames_removed
  File "F:\django\DatabaseConnectTest\polls\models.py", line 9, in <module>
    class Choice(models.Model):
  File "F:\django\DatabaseConnectTest\polls\models.py", line 10, in Choice
    quesion = models.ForeignKey(Question)
TypeError: __init__() missing 1 required positional argument: 'on_delete'

【问题讨论】：

标签： django database python-3.x sqlite

【解决方案1】：

自 Django 2.0 起，所有 ForeignKey 字段都需要 on_delete 参数。不再有默认值。您必须遍历所有模型并将此参数添加到关系中。

回溯会告诉你在哪里可以找到应该修复的代码。

File "F:\django\DatabaseConnectTest\polls\models.py", line 10, in Choice
quesion = models.ForeignKey(Question)

在大多数情况下，on_delete=models.CASCADE 是您想要的。

question = models.ForeignKey(Question, on_delete=models.CASCADE)

https://docs.djangoproject.com/en/2.1/ref/models/fields/#django.db.models.ForeignKey.on_delete

【讨论】：