Django DateTimeField定义为blank=True，null=True，但不允许nu

Question

我的一个Django模型中有一个DateTimeField。

    completed_date = models.DateTimeField('date completed', blank=True, null=True)

我将其定义为允许空白和空值。但是，当我尝试创建模型的实例时，会出现以下错误：

IntegrityError at /admin/tasks/project/add/

tasks_project.completed_date may not be NULL

我使用的是Django 1.25和Python 2.7。有人知道为什么会这样吗？我能做些什么来解决这个问题吗？

我发现了一个ticket that describes the same problem，但它在4年前就已经关闭了，所以我想它现在一定已经集成到Django中了！

Answer 1

django syncdb and an updated model

从这个问题/答案：

Django doesn't support migrations out of the box. There is a pluggable app for Django that does exactly that though, and it works great. It's called South.

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Havent used django in a while, but i seem to remember that syncdb does perform alter commands on db tables. you have to drop the table then run again and it will create again.