Django makemigrations有效，迁移失败并显示"django.db.utils.IntegrityError:NOT NULL约束失败". [英] Django makemigrations works, migrate fails with "django.db.utils.IntegrityError: NOT NULL constraint failed"

问题描述

我被困住了.Django 1.7，SQLite3.

I'm stuck. Django 1.7, SQLite3.

我已更改模型以添加 thumbnail 列，如

I've changed my model to add the thumbnail column, as in this tutorial. It was this:

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

现在是这个:

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

我使用

python manage.py dumpdata article --indent=4 > article.json

然后执行

python manage.py makemigrations

有效.但是

python manage.py migrate

失败

django.db.utils.IntegrityError:NOT NULL约束失败:article_article__new.thumbnail

现在，即使将 null = True 添加到 models.py 中的 thumbnail 行中，也运行了 makemigrations 成功，并且 migrate 失败的方式相同.

And now, even after adding null=True to the thumbnail line in models.py, running makemigrations succeeds, and migrate fails the same way.

我该怎么办?

推荐答案

我的应用程序名称(由 python manage.py startapp 创建)称为 articles .在多次出现空约束错误之后，这是新的 articles \ migrations 文件夹:

My app name (as created with python manage.py startapp) is called articles. Here is the new articles\migrations folder, after getting the null-constraint error multiple times:

__init__.py
0001_initial.py
0002_auto_20140803_1540.py
0003_auto_20140803_1542.py
0004_auto_20140803_1450.py
0005_auto_20140803_1552.py
__pycache__
   __init__.cpython-34.pyc
   0001_initial.cpython-34.pyc
   0002_auto_20140803_1540.cpython-34.pyc
   0003_auto_20140803_1542.cpython-34.pyc
   0004_auto_20140803_1450.cpython-34.pyc
   0005_auto_20140803_1552.cpython-34.pyc

我删除了两个目录中的所有000 *文件，除了0001.

I deleted all the 000* files, in both directories, except 0001.

然后我跑了

python manage.py makemigrations

和

python manage.py migrate

成功.

非常感谢 irc.freenode.net/django .

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