4
我正在玩django框架，并遇到了运行makemigration命令的问题。这里是模型的副本和它生成的堆栈跟踪。 我看到有几个帖子发生同样的错误，但没有一个让我在这里解决我的问题。我使用Django 1.9.4Django makemigrations AttributeError：'str'对象没有属性'_meta'
from django.db import models
import os, uuid
# Create your models here.
def video_directory_path(instance, folder):
return os.path.join('video', str(instance.person.id), str(instance.video_id))
def photo_directory_path(instance, folder):
return os.path.join('image', str(instance.person.id), str(instance.photo_id))
class Image(models.Model):
name = models.CharField(max_length=128)
photo_id = models.UUIDField(verbose_name='photo id', default=uuid.uuid4, editable=False, unique=True)
photo = models.ImageField(upload_to=photo_directory_path)
person = models.ForeignKey('Person', on_delete=models.CASCADE)
movie = models.ForeignKey('Movie', on_delete=models.CASCADE)
class Meta:
db_table = 'Image'
def __str__(self):
return '[{0}- {1}]'.format(self.__class__.__name__, self.id)
def __repr__(self):
return self.__str__()
class Video(models.Model):
name = models.CharField(max_length=128)
video_id = models.UUIDField(verbose_name='video id', default=uuid.uuid4, editable=False, unique=True)
video = models.FileField(upload_to=video_directory_path)
person = models.ForeignKey('Person', on_delete=models.CASCADE)
movie = models.ForeignKey('Movie', on_delete=models.CASCADE)
class Meta:
db_table = 'Video'
def __str__(self):
return '[{0}-{1}]'.format(self.__class__.__name__, self.id)
def __repr__(self):
return self.__str__()
class Filmography(models.Model):
filmography = models.CharField(max_length=128, db_index=True)
class Meta:
db_table = 'Filmography'
def __str__(self):
return '[{0}-{1}]'.format(self.__class__.__name__, self.id)
def __repr__(self):
return self.__str__()
class Person(models.Model):
bio = models.TextField()
filmography = models.ManyToManyField('Filmography')
photos = models.ManyToManyField(
'Image',
through='ImagePerson',
through_fields=('person', 'photo')
)
class Meta:
abstract = True
def __str__(self):
return '[{0}-{1}]'.format(self.__class__.__name__, self.id)
def __repr__(self):
return self.__str__()
class Profile(Person):
first_name = models.CharField(max_length=128, verbose_name="first name")
last_name = models.CharField(max_length=128, verbose_name="last name")
dob = models.DateField()
class Meta:
index_together = ["first_name", "last_name"]
db_table = 'Profile'
class Character(Person):
name = models.CharField(max_length=128)
class Meta:
db_table = 'Character'
class Crew(models.Model):
name = models.CharField(max_length=256)
members = models.ManyToManyField(
'Profile',
through='MovieCrew',
through_fields=('crew', 'profile'),
)
class Meta:
db_table = 'Crew'
def __str__(self):
return '{0}: {1}'.format(self.__class__.__name__, self.name)
def __repr__(self):
return self.__str__()
class MovieCrew(models.Model):
crew = models.ForeignKey(
'Crew',
on_delete=models.CASCADE,
)
profile = models.ForeignKey(
'Profile',
on_delete=models.CASCADE,
)
role = models.CharField(max_length=256)
class Meta:
db_table = 'MovieCrew'
class Genre(models.Model):
genre = models.CharField(max_length=128, db_index=True)
class Meta:
db_table = 'Genre'
class Movie(models.Model):
name = models.CharField(max_length=128, db_index=True)
summary = models.CharField(max_length=256)
story = models.CharField(max_length=256)
release_date = models.DateField()
crew = models.OneToOneField(
'Crew',
on_delete=models.CASCADE,
)
genre = models.ManyToManyField('Genre')
photos = models.ManyToManyField('Image')
videos = models.ManyToManyField('Video')
class Meta:
db_table = 'Movie'
get_latest_by = 'release_date'
def __str__(self):
return '[{0}-{1}]'.format(self.__class__.__name__, self.name)
def __repr__(self):
return self.__str__()
和错误堆栈跟踪工作
Traceback (most recent call last):
File "manage.py", line 10, in <module>
execute_from_command_line(sys.argv)
File "C:\Python34\lib\site-packages\django\core\management\__init__.py", line 353, in execute_from_command_line
utility.execute()
File "C:\Python34\lib\site-packages\django\core\management\__init__.py", line 345, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "C:\Python34\lib\site-packages\django\core\management\base.py", line 348, in run_from_argv
self.execute(*args, **cmd_options)
File "C:\Python34\lib\site-packages\django\core\management\base.py", line 398, in execute
self.check()
File "C:\Python34\lib\site-packages\django\core\management\base.py", line 426, in check
include_deployment_checks=include_deployment_checks,
File "C:\Python34\lib\site-packages\django\core\checks\registry.py", line 75, in run_checks
new_errors = check(app_configs=app_configs)
File "C:\Python34\lib\site-packages\django\core\checks\model_checks.py", line 28, in check_all_models
errors.extend(model.check(**kwargs))
File "C:\Python34\lib\site-packages\django\db\models\base.py", line 1170, in check
errors.extend(cls._check_fields(**kwargs))
File "C:\Python34\lib\site-packages\django\db\models\base.py", line 1249, in _check_fields
errors.extend(field.check(from_model=cls, **kwargs))
File "C:\Python34\lib\site-packages\django\db\models\fields\related.py", line 1165, in check
errors.extend(self._check_relationship_model(**kwargs))
File "C:\Python34\lib\site-packages\django\db\models\fields\related.py", line 1366, in _check_relationship_model
for f in through._meta.fields:
AttributeError: 'str' object has no attribute '_meta'
哇！谢谢...我会试试看。这是一个Django问题吗？ （这是不明确的异常信息） – legend
所以通常你会忽略像''ManyToMany''定义那样的'through'声明。如果您想要在该模型上存储一些其他数据，通常只会传递一个自定义数据。 Django允许在大多数地方传递一个模型或字符串......我很漫不经心，不确定你的问题是什么。 – dreamriver