Python 从models.py迁移数据时出现问题
伙计们,我得到了一个错误,因为你们应该对模型有一个默认值:author、body、created、updated 这是我的models.py配置Python 从models.py迁移数据时出现问题,python,django,django-models,django-admin,django-migrations,Python,Django,Django Models,Django Admin,Django Migrations,伙计们,我得到了一个错误,因为你们应该对模型有一个默认值:author、body、created、updated 这是我的models.py配置 from django.db import models from django.utils import timezone from django.contrib.auth.models import User # Create your models here. class post(models.Model): STATUS_CHOICE
from django.db import models
from django.utils import timezone
from django.contrib.auth.models import User
# Create your models here.
class post(models.Model):
STATUS_CHOICE=(
('draft','DRAFT'),
('published','Published'),
)
title=models.CharField(max_length=250)
slug=models.SlugField(max_length = 250,unique_for_date=1)
author=models.ForeignKey(User,related_name='blog_posts')
body=models.TextField()
publish=models.DateTimeField(default=timezone.now)
created = models.DateTimeField(auto_now_add=True)
updated=models.DateTimeField(auto_now=True)
status = models.CharField(max_length=10,
choices = STATUS_CHOICE,
default='draft')
class Meta:
ordering = ('-publish',)
def __str__(self):
return self.title
迁移数据库时出现以下错误:
You are trying to add a non-nullable field 'body' to post 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
我不确定这些模型的默认值是什么,配置和书中提到的相同,但我仍然得到一个错误
感谢您的任何帮助
提前谢谢
注意:这是一个博客应用程序
当我尝试向模型添加随机默认值时,我得到了以下错误:
更新的models.py:
from django.db import models
from django.utils import timezone
from django.contrib.auth.models import User
# Create your models here.
class post(models.Model):
STATUS_CHOICE=(
('draft','DRAFT'),
('published','Published'),
('admin','admin'),
)
title=models.CharField(max_length=250)
slug=models.SlugField(max_length = 250)
author=models.ForeignKey(User,related_name='blog_posts')
body=models.TextField(default='draft')
publish=models.DateTimeField(default=timezone.now)
created = models.DateTimeField(auto_now_add=True,default=timezone.now)
updated =models.DateTimeField(auto_now=True,default=timezone.now)
status = models.CharField(max_length=10,
choices = STATUS_CHOICE,
default='draft')
class Meta:
ordering = ('-publish',)
def __str__(self):
return self.title
现在的错误是:
ERRORS:
myblog.post.created: (fields.E160) The options auto_now, auto_now_add, and default are mutually exclusive. Only one of these options may
be present.
myblog.post.updated: (fields.E160) The options auto_now, auto_now_add, and default are mutually exclusive. Only one of these options may
be present
为什么不使用null=True,blank=True——这允许模型属性为空 我会将body属性的默认值设置为
body=models.TextField(default='')
时间戳不应该有默认值,您提供的可调用项应该足够了
# Model Timestamp
created = models.DateTimeField(auto_now_add=True)
updated = models.DateTimeField(auto_now=True)
执行迁移时,如果创建和更新的属性遇到缺少默认错误,请选择1并在控制台中输入
时区,现在。将现有行的默认值设置为当前日期时间 错误看起来很清楚,您不需要DateTimeField中的两个选项谢谢您的回复是的,我已经删除了DateTimeField的值并添加了默认值,但仍然要求我提供slug和author,请您确定默认值应该是多少,以便在编辑完您所说的所有内容后查看我的问题仍然会出现此错误:您正在尝试添加字段“created”和“auto\u now\u add=True”,以在没有默认值的情况下发布;数据库需要一些东西来填充现有的行。1提供一个一次性默认值现在将在所有现有行上设置2退出,让我在models中添加一个默认值。py选择一个选项:myblog\models。py14:71我更改了答案,现在应该通过了。谢谢它工作了,我刚刚为所有这些添加了null=true,如果你想帮助像我这样的孩子解决问题,请加入这个团队: