我被困住了。 Django 1.7、SQLite3。
我已经更改了模型以添加thumbnail
列,如本教程 https://www.youtube.com/watch?v=b43JIn-OGZU。原来是这样的:
from django.db import models
class Article(models.Model):
title = models.CharField(max_length=200)
body = models.TextField()
pub_date = models.DateTimeField('date published')
likes = models.IntegerField(default=0)
def __str__(self):
return self.title
现在是这样的:
from django.db import models
from time import time
def get_upload_file_name(instance, filename):
return "uploaded_files/%s_%s" % (str(time()).replace(".", "_"), filename)
class Article(models.Model):
title = models.CharField(max_length=200)
body = models.TextField()
pub_date = models.DateTimeField('date published')
likes = models.IntegerField(default=0)
thumbnail = models.FileField(upload_to=get_upload_file_name, null=True)
def __str__(self):
return self.title
我将所有数据备份到 json 文本文件中
python manage.py dumpdata article --indent=4 > article.json
然后执行
python manage.py makemigrations
这有效。但
python manage.py migrate
失败了
django.db.utils.IntegrityError: NOT NULL constraint failed: article_article__new.thumbnail
现在,即使添加了null=True
to the thumbnail
线路输入models.py
, 跑步makemigrations
成功,并且migrate
同样失败。
我该怎么办?