python - 迁移时 Django 错误(int() 和 datetime.datetime)

Question

我认为这是一个基本错误，但我正在尝试进行一些测试，但现在无法迁移内容。我已经正常创建了 python manage.py makemigrations 但在使用“migrate”时出现消息错误:

C:\P3\P3\urls.py:21: RemovedInDjango110Warning: Support for string view arguments to url() is deprecated and will be removed in Django 1.10 (got quizzy.views.primeraprox). Pass the callable instead.
  url(r'^primaprox/', 'quizzy.views.primeraprox'),

Operations to perform:
  Apply all migrations: contenttypes, admin, sessions, quizzy, auth
Running migrations:
  Rendering model states... DONE
  Applying quizzy.0002_auto_20160313_1718...Traceback (most recent call last):
  File "manage.py", line 10, in <module>
    execute_from_command_line(sys.argv)
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\core\management\__init__.py", line 353, in execute_from_command_line
    utility.execute()
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\core\management\__init__.py", line 345, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\core\management\base.py", line 348, in run_from_argv
    self.execute(*args, **cmd_options)
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\core\management\base.py", line 399, in execute
    output = self.handle(*args, **options)
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\core\management\commands\migrate.py", line 200, in handle
    executor.migrate(targets, plan, fake=fake, fake_initial=fake_initial)
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\db\migrations\executor.py", line 92, in migrate
    self._migrate_all_forwards(plan, full_plan, fake=fake, fake_initial=fake_initial)
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\db\migrations\executor.py", line 121, in _migrate_all_forwards
    state = self.apply_migration(state, migration, fake=fake, fake_initial=fake_initial)
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\db\migrations\executor.py", line 198, in apply_migration
    state = migration.apply(state, schema_editor)
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\db\migrations\migration.py", line 123, in apply
    operation.database_forwards(self.app_label, schema_editor, old_state, project_state)
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\db\migrations\operations\fields.py", line 62, in database_forwards
    field,
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\db\backends\base\schema.py", line 382, in add_field
    definition, params = self.column_sql(model, field, include_default=True)
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\db\backends\base\schema.py", line 145, in column_sql
    default_value = self.effective_default(field)
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\db\backends\base\schema.py", line 210, in effective_default
    default = field.get_db_prep_save(default, self.connection)
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\db\models\fields\related.py", line 912, in get_db_prep_save
    return self.target_field.get_db_prep_save(value, connection=connection)
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\db\models\fields\__init__.py", line 728, in get_db_prep_save
    prepared=False)
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\db\models\fields\__init__.py", line 968, in get_db_prep_value
    value = self.get_prep_value(value)
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\db\models\fields\__init__.py", line 976, in get_prep_value
    return int(value)
TypeError: int() argument must be a string, a bytes-like object or a number, not 'datetime.datetime'

另外，URL 有什么问题吗？

我的 models.py 看起来像这样:

from django.db import models
from django.utils import timezone

class Questions(models.Model):
    content = models.CharField(max_length=200)
    pub_date = models.DateTimeField('datetime field', default=True)

    def __str__(self):
        return self.content

class Answer(models.Model):
    answer_text = models.CharField(max_length=200)
    first_field = models.CharField(max_length=150)
    question = models.ManyToManyField(Questions)

    def __str__(self):
        return self.answer_text

我只是希望能够进行迁移，并且无法弄清楚为什么 Django 会给出有关“datetime.datetime”的错误。我真的很感激任何帮助。谢谢。

编辑 1:我更改了 pub_date 字段。然后“makemigrations”，它返回:

C:\P3>python manage.py makemigrations
C:\P3\P3\urls.py:21: RemovedInDjango110Warning: Support for string view arguments to url() is deprecated and will be removed in Django 1.10 (got quizzy.views.primeraprox). Pass the callable instead.
  url(r'^primaprox/', 'quizzy.views.primeraprox'),

System check identified some issues:

WARNINGS:
quizzy.Questions.pub_date: (fields.W161) Fixed default value provided.
        HINT: It seems you set a fixed date / time / datetime value as default for this field. This may not be what you want. If you want to have the current date as default, use `django.utils.timezone.now`
Migrations for 'quizzy':
  0012_auto_20160313_1810.py:
    - Alter field pub_date on questions

然后，当我再次运行“迁移”时，错误消息是相同的。怎么了？谢谢

编辑 2:如果您请求“进行迁移”的上述文本就是这个:

C:\P3>python manage.py makemigrations
C:\P3\P3\urls.py:21: RemovedInDjango110Warning: Support for string view arguments to url() is deprecated and will be removed in Django 1.10 (got quizzy.views.primeraprox). Pass the callable instead.
  url(r'', 'quizzy.views.primeraprox'),

You are trying to add a non-nullable field 'quiz' to questions 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)
 2) Quit, and let me add a default in models.py
Select an option: 1
Please enter the default value now, as valid Python
The datetime and django.utils.timezone modules are available, so you can do e.g. timezone.now()
>>> timezone.now()
Migrations for 'quizzy':
  0002_auto_20160313_1718.py:
    - Create model Quiz
    - Add field quiz to questions

这属于我所做的一些更改，但现在我已将其删除，也许可能存在错误。

编辑3:将 pub_date 设置为 (auto_now=True) 时，完整的迁移如下:

C:\P3>python manage.py migrate
C:\P3\P3\urls.py:21: RemovedInDjango110Warning: Support for string view arguments to url() is deprecated and will be removed in Django 1.10 (got quizzy.views.primeraprox). Pass the callable instead.
  url(r'^primaprox/', 'quizzy.views.primeraprox'),

Operations to perform:
  Apply all migrations: quizzy, contenttypes, sessions, auth, admin
Running migrations:
  Rendering model states... DONE
  Applying quizzy.0002_auto_20160313_1718...Traceback (most recent call last):
  File "manage.py", line 10, in <module>
    execute_from_command_line(sys.argv)
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\core\management\__init__.py", line 353, in execute_from_command_line
    utility.execute()
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\core\management\__init__.py", line 345, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\core\management\base.py", line 348, in run_from_argv
    self.execute(*args, **cmd_options)
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\core\management\base.py", line 399, in execute
    output = self.handle(*args, **options)
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\core\management\commands\migrate.py", line 200, in handle
    executor.migrate(targets, plan, fake=fake, fake_initial=fake_initial)
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\db\migrations\executor.py", line 92, in migrate
    self._migrate_all_forwards(plan, full_plan, fake=fake, fake_initial=fake_initial)
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\db\migrations\executor.py", line 121, in _migrate_all_forwards
    state = self.apply_migration(state, migration, fake=fake, fake_initial=fake_initial)
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\db\migrations\executor.py", line 198, in apply_migration
    state = migration.apply(state, schema_editor)
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\db\migrations\migration.py", line 123, in apply
    operation.database_forwards(self.app_label, schema_editor, old_state, project_state)
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\db\migrations\operations\fields.py", line 62, in database_forwards
    field,
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\db\backends\base\schema.py", line 382, in add_field
    definition, params = self.column_sql(model, field, include_default=True)
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\db\backends\base\schema.py", line 145, in column_sql
    default_value = self.effective_default(field)
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\db\backends\base\schema.py", line 210, in effective_default
    default = field.get_db_prep_save(default, self.connection)
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\db\models\fields\related.py", line 912, in get_db_prep_save
    return self.target_field.get_db_prep_save(value, connection=connection)
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\db\models\fields\__init__.py", line 728, in get_db_prep_save
    prepared=False)
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\db\models\fields\__init__.py", line 968, in get_db_prep_value
    value = self.get_prep_value(value)
  File "C:\Python\lib\site-packages\django-1.9.1-py3.5.egg\django\db\models\fields\__init__.py", line 976, in get_prep_value
    return int(value)
TypeError: int() argument must be a string, a bytes-like object or a number, not 'datetime.datetime'

编辑 4(迁移):迁移文件包含:

class Migration(migrations.Migration):

    dependencies = [
        ('quizzy', '0001_initial'),
    ]

    operations = [
        migrations.CreateModel(
            name='Quiz',
            fields=[
                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
                ('name', models.TextField(default='true', max_length=200)),
            ],
        ),
        migrations.AddField(
            model_name='questions',
            name='quiz',
            field=models.ForeignKey(default=datetime.datetime(2016, 3, 13, 16, 18, 27, 23857, tzinfo=utc), on_delete=django.db.models.deletion.CASCADE, to='quizzy.Quiz'),
            preserve_default=False,
        ),
    ]

Answer 1

您的pubdate有一个 bool 值的默认值，您应该给它一个日期时间或autonow

pub_date = models.DateTimeField(auto_now=True)
pub_date = models.DateTimeField(default=timezone.now)

<小时/>

您面临的实际问题是您将外键的默认值设置为日期时间，您可以将其设置为某个 ID 或允许空值

    migrations.AddField(
        model_name='questions',
        name='quiz',
        field=models.ForeignKey(default=1, on_delete=django.db.models.deletion.CASCADE, to='quizzy.Quiz'), # or null=True
        preserve_default=False,
    ),