Django 错误：“您正试图在没有默认值的情况下向条目添加不可为空的字段‘作者’”

Question

在我的 models.py 文件中添加了一个 author 字段后，我试图进行迁移，但 Django 问我这个：

You are trying to add a non-nullable field 'author' to entry 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

我的 Models.py 文件：

from django.db import models
from django.utils import timezone
from django.urls import reverse
from django.contrib.auth.models import User


class Entry(models.Model):
    title = models.CharField(max_length=50, default=timezone.now)
    date = models.DateTimeField(default=timezone.now)
    content = models.TextField()
    author = models.ForeignKey(User, on_delete=models.CASCADE)

    def get_absolute_url(self):
        return reverse('diary:index')

    def __str__(self):
        return self.title

我想添加当前活跃的用户作为作者，所以我在我的 views.py 文件中做了这个：

class EntryCreate(CreateView):
    model = Entry
    fields = ['title', 'content']

    def form_valid(self, form):
        form.instance.author = self.request.author
        return super().form_valid(form)

我应该怎么做才能避免这种情况？

提前致谢！

Answer 1

添加一个default=None给你的作者