当我在我的文件上运行 python manage.py migrate 时,出现了这个 ValueError。
Operations to perform:
Apply all migrations: admin, auth, cms, contenttypes, sessions
Running migrations:
Applying cms.0002_auto_20170401_2307...Traceback (most recent call last):
File "manage.py", line 22, in <module>
execute_from_command_line(sys.argv)
File "C:\Users\sndys\project\lib\site-packages\django\core\management\__init__.py", line 367, in execute_from_command_line
utility.execute()
File "C:\Users\sndys\project\lib\site-packages\django\core\management\__init__.py", line 359, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "C:\Users\sndys\project\lib\site-packages\django\core\management\base.py", line 294, in run_from_argv
self.execute(*args, **cmd_options)
File "C:\Users\sndys\project\lib\site-packages\django\core\management\base.py", line 345, in execute
output = self.handle(*args, **options)
File "C:\Users\sndys\project\lib\site-packages\django\core\management\commands\migrate.py", line 204, in handle
fake_initial=fake_initial,
File "C:\Users\sndys\project\lib\site-packages\django\db\migrations\executor.py", line 115, in migrate
state = self._migrate_all_forwards(state, plan, full_plan, fake=fake, fake_initial=fake_initial)
File "C:\Users\sndys\project\lib\site-packages\django\db\migrations\executor.py", line 145, in _migrate_all_forwards
state = self.apply_migration(state, migration, fake=fake, fake_initial=fake_initial)
File "C:\Users\sndys\project\lib\site-packages\django\db\migrations\executor.py", line 244, in apply_migration
state = migration.apply(state, schema_editor)
File "C:\Users\sndys\project\lib\site-packages\django\db\migrations\migration.py", line 129, in apply
operation.database_forwards(self.app_label, schema_editor, old_state, project_state)
File "C:\Users\sndys\project\lib\site-packages\django\db\migrations\operations\fields.py", line 84, in database_forwards
field,
File "C:\Users\sndys\project\lib\site-packages\django\db\backends\sqlite3\schema.py", line 231, in add_field
self._remake_table(model, create_fields=[field])
File "C:\Users\sndys\project\lib\site-packages\django\db\backends\sqlite3\schema.py", line 113, in _remake_table
self.effective_default(field)
File "C:\Users\sndys\project\lib\site-packages\django\db\backends\base\schema.py", line 221, in effective_default
default = field.get_db_prep_save(default, self.connection)
File "C:\Users\sndys\project\lib\site-packages\django\db\models\fields\related.py", line 909, in get_db_prep_save
return self.target_field.get_db_prep_save(value, connection=connection)
File "C:\Users\sndys\project\lib\site-packages\django\db\models\fields\__init__.py", line 755, in get_db_prep_save
prepared=False)
File "C:\Users\sndys\project\lib\site-packages\django\db\models\fields\__init__.py", line 938, in get_db_prep_value
value = self.get_prep_value(value)
File "C:\Users\sndys\project\lib\site-packages\django\db\models\fields\__init__.py", line 946, in get_prep_value
return int(value)
ValueError: invalid literal for int() with base 10: 'NULL'
我的 models.py 文件:
from django.db import models
from django.contrib.auth.models import User
import markdown
# Create your models here.
class Tag(models.Model):
name = models.CharField(max_length=32)
slug = models.SlugField()
def __str__(self):
return self.name
class Category(models.Model):
name = models.CharField(max_length=32)
slug = models.SlugField()
description = models.TextField()
image = models.ImageField()
def __str__(self):
return self.name
class Image(models.Model):
name = models.CharField(max_length=32)
slug = models.SlugField()
alt_text = models.CharField(max_length=255)
image = models.ImageField()
def __str__(self):
return self.name
class Gallery(models.Model):
name = models.CharField(max_length=32)
slug = models.SlugField()
images = models.ManyToManyField(Image)
description = models.TextField()
layout = models.CharField(
max_length=5,
choices=(
('LINK', 'Linked'),
('HORI', 'Horizontal'),
('VERT', 'Vertical')))
def __str__(self):
return self.name
class Article(models.Model):
title = models.CharField(max_length=255)
slug = models.SlugField()
author = models.ForeignKey(User)
content = models.TextField()
creation_date = models.DateTimeField(auto_now_add=True)
edit_date = models.DateTimeField(auto_now=True)
featured_image = models.ImageField(null=True, blank=True)
publish_status = models.BooleanField(default=False)
category = models.ForeignKey(Category)
tags = models.ManyToManyField(Tag)
@property
def content_html(self):
return markdown.markdown(self.content)
def __str__(self):
return self.title
class Meta:
verbose_name_plural = 'Articles'
ordering = ['creation_date']`enter code here`
当我执行 python manage.py makemigrations 时,出现了:
您正在尝试在没有默认值的情况下向文章添加不可为空的字段“类别”;我们不能那样做(数据库需要一些东西来填充现有行)。 请选择一个修复:
1) 现在提供一次性默认值(将在所有现有行上设置此列的空值)
2) 退出,让我在 models.py 中添加一个默认值
选择一个选项:
我选择了 1 并给出了默认值“NULL”,我认为这可能是我犯的错误。在此“python manage.py makemigrations”成功运行之后,但“python manage.py migrate”出现错误。 在此之后,我尝试为 Article 类中的类别外键提供默认值 = 1,但迁移时出现相同的错误。
谁能告诉我问题出在哪里以及如何解决。
最佳答案
您不应该提供希望数据库接收的值。您在 Python 中给出值。但是,只有在该字段上未设置 null=True 时,您才会收到该消息。删除迁移并在该字段上设置 null=True。
关于python - 值错误 : invalid literal for int() with base 10: 'NULL' ,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/43160365/