Python 首次迁移到新的PostgreSQL数据库。ValueError:基数为10的int（）的文本无效：“”

拥有成功使用SQLite数据库的models.py。现在正在尝试使用PostgreSQL。如果查看回溯，似乎整数字段有一个字符串默认值。我就是看不见。注释了大多数字段，进行了迁移，但仍然存在相同的问题

回溯

 Operations to perform:
  Apply all migrations: admin, auth, contenttypes, players, sessions, silk, users
Running migrations:
  Applying players.0007_auto_20190130_1427...Traceback (most recent call last):
  File "D:\temp\YandexDisk\programming\py\nhl_web_app\manage.py", line 15, in <module>
    execute_from_command_line(sys.argv)
  File "c:\program files\python37\lib\site-packages\django\core\management\__init__.py",
 line 381, in execute_from_command_line
    utility.execute()
  File "c:\program files\python37\lib\site-packages\django\core\management\__init__.py",
 line 375, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "c:\program files\python37\lib\site-packages\django\core\management\base.py", lin
e 316, in run_from_argv
    self.execute(*args, **cmd_options)
  File "c:\program files\python37\lib\site-packages\django\core\management\base.py", lin
e 353, in execute
    output = self.handle(*args, **options)
  File "c:\program files\python37\lib\site-packages\django\core\management\base.py", lin
e 83, in wrapped
    res = handle_func(*args, **kwargs)
  File "c:\program files\python37\lib\site-packages\django\core\management\commands\migr
ate.py", line 203, in handle
    fake_initial=fake_initial,
  File "c:\program files\python37\lib\site-packages\django\db\migrations\executor.py", l
ine 117, in migrate
    state = self._migrate_all_forwards(state, plan, full_plan, fake=fake, fake_initial=f
ake_initial)
  File "c:\program files\python37\lib\site-packages\django\db\migrations\executor.py", l
ine 147, in _migrate_all_forwards
    state = self.apply_migration(state, migration, fake=fake, fake_initial=fake_initial)

  File "c:\program files\python37\lib\site-packages\django\db\migrations\executor.py", l
ine 244, in apply_migration
    state = migration.apply(state, schema_editor)
  File "c:\program files\python37\lib\site-packages\django\db\migrations\migration.py",
line 124, in apply
    operation.database_forwards(self.app_label, schema_editor, old_state, project_state)

  File "c:\program files\python37\lib\site-packages\django\db\migrations\operations\fiel
ds.py", line 216, in database_forwards
    schema_editor.alter_field(from_model, from_field, to_field)
  File "c:\program files\python37\lib\site-packages\django\db\backends\base\schema.py",
line 523, in alter_field
    old_db_params, new_db_params, strict)
  File "c:\program files\python37\lib\site-packages\django\db\backends\postgresql\schema
.py", line 122, in _alter_field
    new_db_params, strict,
  File "c:\program files\python37\lib\site-packages\django\db\backends\base\schema.py",
line 627, in _alter_field
    new_default = self.effective_default(new_field)
  File "c:\program files\python37\lib\site-packages\django\db\backends\base\schema.py",
line 239, in effective_default
    return field.get_db_prep_save(default, self.connection)
  File "c:\program files\python37\lib\site-packages\django\db\models\fields\__init__.py"
, line 790, in get_db_prep_save
    return self.get_db_prep_value(value, connection=connection, prepared=False)
  File "c:\program files\python37\lib\site-packages\django\db\models\fields\__init__.py"
, line 785, in get_db_prep_value
    value = self.get_prep_value(value)
  File "c:\program files\python37\lib\site-packages\django\db\models\fields\__init__.py"
, line 1807, in get_prep_value
    return int(value)
ValueError: invalid literal for int() with base 10: ''

设置.py

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql',
        'NAME': 'nhl_web_app_1',
        'USER': 'postgres',
        'PASSWORD': '***',
        'HOST': 'localhost',
        'PORT': '5432',
    }
}

---

在@awesoon的帮助下，我找到了错误

问题出现在迁移文件0007_auto_20190130_1427.py中

我有一个整数字段的字符串默认值-默认值=

需要将此默认值替换为任何整数

migrations.AlterField(
    model_name='skater',
    name='time_on_ice_pp',
    field=models.IntegerField(default=10, null=True),
),

---

请提供0007_auto_20190130_1427.py迁移的内容file@awesoon你说得对。我只是无法正确地阅读回溯。没想到它会尝试应用一个旧的迁移文件。已删除所有迁移，现在无法应用新的初始迁移。它说“没有要应用的迁移”-Screen您是否也回滚了DB？如果这是没有任何生产数据的本地数据库，则可以通过指定要应用的最新迁移进行回滚，使用原始DDL手动回滚，或直接删除并重新创建数据库。migrate不知道旧迁移或新迁移，它只知道应用了或未应用了哪些迁移，默认情况下，它会尝试应用所有未应用的迁移。所有应用的迁移都存储在django_migrations表中。

migrations.AlterField(
    model_name='skater',
    name='time_on_ice_pp',
    field=models.IntegerField(default='', null=True),
),

migrations.AlterField(
    model_name='skater',
    name='time_on_ice_pp',
    field=models.IntegerField(default=10, null=True),
),