django migrate 报错

class Category(models.Model):
name = models.CharField(u'文章分类', max_length=64)

def __str__(self):
    return self.name


class article(models.Model):
    title = models.CharField(u'标题', max_length=60)
    category = models.ManyToManyField('Category', verbose_name=u'分类', blank=True)
    createtime = models.DateTimeField(u'createtime', default=timezone.now)
    content = models.TextField(u'内容', blank=True, null=True)

报错如下：

 File "C:\Users\lujunhong\Desktop\work\venv\lib\site-packages\django\db\models\options.py", line 614, in get_field
raise FieldDoesNotExist('%s has no field named %r' % (self.object_name, field_name))
django.core.exceptions.FieldDoesNotExist: Category has no field named '文章分类'

请问为什么会提示没有这个字段呢

10 replies • 2016-10-31 18:26:14 +08:00

upczww

Oct 30, 2016 via Smartisan T1

给你提个建议，写字段的时候最好都统一一下，写成
关键字参数形式。把文章分类用 verbose_name = "文章分类" 这样写。

lovebeyondalways

Oct 30, 2016

@upczww 谢谢提醒，可是上面提出的问题是什么原因呢，明明增加了这个字段

upczww

Oct 30, 2016

@lovebeyondalways 你试试这样写：
name = models.CharField(verbose_name = u'文章分类', max_length=64)
估计你直接用位置参数，没用对位置。

lxy42

Oct 30, 2016 via Android

category = models.ManyToManyField('category'...)
这里，去掉引号。

lxy42

Oct 30, 2016 via Android

ManyToManyField 第一个参数是 Model class

jimmyye

Oct 31, 2016

试过了，没有问题
```
class Category(models.Model):
name = models.CharField(u'文章分类', max_length=64)

def __str__(self):
return self.name

class article(models.Model):
title = models.CharField(u'标题', max_length=60)
category = models.ManyToManyField('Category', verbose_name=u'分类', blank=True)
createtime = models.DateTimeField(u'createtime', default=timezone.now)
content = models.TextField(u'内容', blank=True, null=True)
```
```
➜ temp python manage.py makemigrations
Migrations for 'core':
core/migrations/0001_initial.py:
- Create model article
- Create model Category
- Add field category to article
➜ temp python manage.py migrate
Operations to perform:
Apply all migrations: admin, auth, contenttypes, core, sessions
Running migrations:
Applying contenttypes.0001_initial... OK
Applying auth.0001_initial... OK
Applying admin.0001_initial... OK
Applying admin.0002_logentry_remove_auto_add... OK
Applying contenttypes.0002_remove_content_type_name... OK
Applying auth.0002_alter_permission_name_max_length... OK
Applying auth.0003_alter_user_email_max_length... OK
Applying auth.0004_alter_user_username_opts... OK
Applying auth.0005_alter_user_last_login_null... OK
Applying auth.0006_require_contenttypes_0002... OK
Applying auth.0007_alter_validators_add_error_messages... OK
Applying auth.0008_alter_user_username_max_length... OK
Applying core.0001_initial... OK
Applying sessions.0001_initial... OK
➜ temp
```

lovebeyondalways

Oct 31, 2016 via Android

Category 这个类是我后面加上去的不知道有没有影响

jimmyye

Oct 31, 2016

@lovebeyondalways 每次修改 /增加 Model 后，都要先`python manage.py makemigrations`生成 migration 文件，然后`python manage.py migrate`应用到数据库。

lovebeyondalways

Oct 31, 2016

@jimmyye 谢谢啊这个试用了一样的，最后我把 migrations 文件里内容删了，又把数据库清空，再生成就 OK 了
最原始的办法

maemo

Oct 31, 2016

之前我遇到类似的问题，是用:
python manage.py migrate --fake appname