Python 迁移期间出错

我在将模型迁移到数据库时遇到问题

models.py：

# coding: utf-8
from django.db import models
# Create your models here.

class Product(models.Model):
    title = models.CharField('title', max_length=100, blank=False)
    author = models.CharField('author', max_length=100, blank=False)

    def __unicode__(self):
        return "%s - %s" % (self.title,self.author)

    class Meta:
        verbose_name = 'Produkt'
        verbose_name_plural = 'Produkty'

这是错误日志：

Operations to perform:
  Synchronize unmigrated apps: django_extensions
  Apply all migrations: admin, TestApp, contenttypes, auth, sessions
Synchronizing apps without migrations:
  Creating tables...
  Installing custom SQL...
  Installing indexes...
Running migrations:
  Applying contenttypes.0001_initial... OK
  Applying auth.0001_initial... OK
  Applying TestApp.0001_initial... OK
  Applying TestApp.0002_auto_20141104_1305... OK
  Applying TestApp.0003_auto_20141104_1312... OK
  Applying TestApp.0004_genretype_producttype... OK
  Applying TestApp.0005_auto_20141104_1322... OK
  Applying TestApp.0006_auto_20141104_1338... OK
  Applying TestApp.0007_product_producttype... OK
  Applying TestApp.0008_auto_20141106_0852...Traceback (most recent call last):
  File "C:\Program Files (x86)\JetBrains\PyCharm 3.4.1\helpers\pycharm\django_manage.py", line 23, in <module>
    run_module(manage_file, None, '__main__', True)
  File "C:\Python27\lib\runpy.py", line 176, in run_module
    fname, loader, pkg_name)
  File "C:\Python27\lib\runpy.py", line 82, in _run_module_code
    mod_name, mod_fname, mod_loader, pkg_name)
  File "C:\Python27\lib\runpy.py", line 72, in _run_code
    exec code in run_globals
  File "C:\Users\Martin\PycharmProjects\SPJA_PROJECT_Videoshop\manage.py", line 10, in <module>
    execute_from_command_line(sys.argv)
  File "C:\Python27\lib\site-packages\django\core\management\__init__.py", line 385, in execute_from_command_line
    utility.execute()
  File "C:\Python27\lib\site-packages\django\core\management\__init__.py", line 377, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "C:\Python27\lib\site-packages\django\core\management\base.py", line 288, in run_from_argv
    self.execute(*args, **options.__dict__)
  File "C:\Python27\lib\site-packages\django\core\management\base.py", line 338, in execute
    output = self.handle(*args, **options)
  File "C:\Python27\lib\site-packages\django\core\management\commands\migrate.py", line 160, in handle
    executor.migrate(targets, plan, fake=options.get("fake", False))
  File "C:\Python27\lib\site-packages\django\db\migrations\executor.py", line 63, in migrate
    self.apply_migration(migration, fake=fake)
  File "C:\Python27\lib\site-packages\django\db\migrations\executor.py", line 97, in apply_migration
    migration.apply(project_state, schema_editor)
  File "C:\Python27\lib\site-packages\django\db\migrations\migration.py", line 107, in apply
    operation.database_forwards(self.app_label, schema_editor, project_state, new_state)
  File "C:\Python27\lib\site-packages\django\db\migrations\operations\fields.py", line 139, in database_forwards
    schema_editor.alter_field(from_model, from_field, to_field)
  File "C:\Python27\lib\site-packages\django\db\backends\schema.py", line 473, in alter_field
    self._alter_field(model, old_field, new_field, old_type, new_type, old_db_params, new_db_params, strict)
  File "C:\Python27\lib\site-packages\django\db\backends\sqlite3\schema.py", line 190, in _alter_field
    self._remake_table(model, alter_fields=[(old_field, new_field)])
  File "C:\Python27\lib\site-packages\django\db\backends\sqlite3\schema.py", line 128, in _remake_table
    self.create_model(temp_model)
  File "C:\Python27\lib\site-packages\django\db\backends\schema.py", line 209, in create_model
    definition, extra_params = self.column_sql(model, field)
  File "C:\Python27\lib\site-packages\django\db\backends\schema.py", line 121, in column_sql
    default_value = self.effective_default(field)
  File "C:\Python27\lib\site-packages\django\db\backends\schema.py", line 184, in effective_default
    default = field.get_db_prep_save(default, self.connection)
  File "C:\Python27\lib\site-packages\django\db\models\fields\__init__.py", line 627, in get_db_prep_save
    prepared=False)
  File "C:\Python27\lib\site-packages\django\db\models\fields\__init__.py", line 1176, in get_db_prep_value
    value = self.get_prep_value(value)
  File "C:\Python27\lib\site-packages\django\db\models\fields\__init__.py", line 1171, in get_prep_value
    return self.to_python(value)
  File "C:\Python27\lib\site-packages\django\db\models\fields\__init__.py", line 1128, in to_python
    parsed = parse_date(value)
  File "C:\Python27\lib\site-packages\django\utils\dateparse.py", line 37, in parse_date
    match = date_re.match(value)
TypeError: expected string or buffer

Process finished with exit code 1

---

0008_auto_20141106_0852中的迁移无效：

您有一个日期字段，但默认值是整数。您需要将此字段从日期字段更改为整数字段，然后再次运行迁移：

migrations.AlterField(
    model_name='product',
    name='year',
    field=models.IntegerField(default=2000, verbose_name=b'year'),
    preserve_default=False,
),

---

进行此更改，您的迁移应该可以正常工作。

什么是countfree？错误，我现在编辑了原始代码您可以将迁移文件0008\u auto\u 20141106\u 0852的内容放入吗？

migrations.AlterField(
    model_name='product',
    name='year',
    field=models.DateField(default=2000, verbose_name=b'year'),
    preserve_default=True,
),

migrations.AlterField(
    model_name='product',
    name='year',
    field=models.IntegerField(default=2000, verbose_name=b'year'),
    preserve_default=False,
),