python - Django 拒绝接受我对 FloatField 的一次性默认值

Question

我有一个类，我正在尝试向它添加一个新的 FloatField。 Django 想要一个默认值来填充现有行(合理)。但是，它拒绝接受我给它的任何值。

You are trying to add a non-nullable field 'FIELDNAME' to CLASS without a default; we can't do that (the database needs something to populate existing rows).
Please select a fix:
 1) Provide a one-off default now (will be set on all existing rows with a null value for this column)
 2) Quit, and let me add a default in models.py
Select an option: -1
Please select a valid option: -1
Please select a valid option: -1
Please select a valid option: float(-1)
Please select a valid option: -1.0
Please select a valid option: float(-1.0)
Please select a valid option: 

如何让它接受我的值？

Answer 1

您应该选择选项 1，然后输入您的值

 1) Provide a one-off default now (will be set on all existing rows with a null value for this column)
 2) Quit, and let me add a default in models.py
 1

选择 1 后，它会要求提供您的默认值。

Please enter the default value now, as valid Python
The datetime and django.utils.timezone modules are available, so you can do e.g. timezone.now()
>>> -1.0