You are trying to add a non-nullable field 'name' to contact 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: 



django 报错-You are trying to add a non-nullable fie_non-nullable django


原因：因为新增加了一个字段，而在此之前的数据，肯定是没有值的，但这个字段不能为空，所以需要一个默认值。或者也可以把这个字段允许为空。

解决方法：

先给'name'任意初始值：name = models.CharField(max_length=50, default='')

然后执行：python manage.py makemirations

再执行：python manage.py migrate



再将default删去，即执行：name = models.CharField(max_length=50)

执行：python manage.py makemirations

再执行：python manage.py migrate

django 报错-You are trying to add a non-nullable fie_non-nullable django_02


解决！

转正:

​​https://www.cnblogs.com/aaron-agu/p/8985055.html​​