从 Django 1.7 到 1.8 的自动提交迁移

Question

我正在通过以下步骤从 Django 1.7 迁移到 1.8

1. 活动虚拟环境
2. 卸载 Django 1.7
3. 安装 Django 1.8
4. python manage.py runserver

在执行第 4 步时，我收到以下错误。

Unhandled exception in thread started by <function wrapper at 0x7f4e473a8230>
Traceback (most recent call last):
  File "/home/lenovo/Envs/boilerplate/local/lib/python2.7/site-packages/django/utils/autoreload.py", line 223, in wrapper
    fn(*args, **kwargs)
  File "/home/lenovo/Envs/boilerplate/local/lib/python2.7/site-packages/django/core/management/commands/runserver.py", line 112, in inner_run
    self.check_migrations()
  File "/home/lenovo/Envs/boilerplate/local/lib/python2.7/site-packages/django/core/management/commands/runserver.py", line 164, in check_migrations
    executor = MigrationExecutor(connections[DEFAULT_DB_ALIAS])
  File "/home/lenovo/Envs/boilerplate/local/lib/python2.7/site-packages/django/db/migrations/executor.py", line 19, in __init__
    self.loader = MigrationLoader(self.connection)
  File "/home/lenovo/Envs/boilerplate/local/lib/python2.7/site-packages/django/db/migrations/loader.py", line 47, in __init__
    self.build_graph()
  File "/home/lenovo/Envs/boilerplate/local/lib/python2.7/site-packages/django/db/migrations/loader.py", line 180, in build_graph
    self.applied_migrations = recorder.applied_migrations()
  File "/home/lenovo/Envs/boilerplate/local/lib/python2.7/site-packages/django/db/migrations/recorder.py", line 59, in applied_migrations
    self.ensure_schema()
  File "/home/lenovo/Envs/boilerplate/local/lib/python2.7/site-packages/django/db/migrations/recorder.py", line 49, in ensure_schema
    if self.Migration._meta.db_table in self.connection.introspection.table_names(self.connection.cursor()):
  File "/home/lenovo/Envs/boilerplate/local/lib/python2.7/site-packages/django/db/backends/base/base.py", line 162, in cursor
    cursor = self.make_debug_cursor(self._cursor())
  File "/home/lenovo/Envs/boilerplate/local/lib/python2.7/site-packages/django/db/backends/base/base.py", line 135, in _cursor
    self.ensure_connection()
  File "/home/lenovo/Envs/boilerplate/local/lib/python2.7/site-packages/django/db/backends/base/base.py", line 130, in ensure_connection
    self.connect()
  File "/home/lenovo/Envs/boilerplate/local/lib/python2.7/site-packages/django/db/utils.py", line 97, in __exit__
    six.reraise(dj_exc_type, dj_exc_value, traceback)
  File "/home/lenovo/Envs/boilerplate/local/lib/python2.7/site-packages/django/db/backends/base/base.py", line 130, in ensure_connection
    self.connect()
  File "/home/lenovo/Envs/boilerplate/local/lib/python2.7/site-packages/django/db/backends/base/base.py", line 119, in connect
    self.connection = self.get_new_connection(conn_params)
  File "/home/lenovo/Envs/boilerplate/local/lib/python2.7/site-packages/django/db/backends/postgresql_psycopg2/base.py", line 172, in get_new_connection
    connection = Database.connect(**conn_params)
  File "/home/lenovo/Envs/boilerplate/local/lib/python2.7/site-packages/psycopg2/__init__.py", line 164, in connect
    conn = _connect(dsn, connection_factory=connection_factory, async=async)
django.db.utils.OperationalError: invalid connection option "autocommit"

错误似乎来自 psycopg2 模块并与自动提交有关。在 1.8 文档的 feature removed 部分中，我找到了以下行。

the decorators and context managers autocommit, commit_on_success, and commit_manually, defined in django.db.transaction

我无法将这与我遇到的错误联系起来。有人可以解释一下吗？

更新：

我找到了原因。下面是我的数据库连接配置。其中有自动提交=真。在评论该行时，问题得到了解决。但我仍然想知道为什么我们不能提供 autocommit=True 选项。

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql_psycopg2',
        'HOST': 'localhost',
        'PORT': '5432',
        'NAME': 'bp_django_auth',
        'USER': 'postgres',
        'PASSWORD': 'abcd1234',
        'OPTIONS': {
            "autocommit": True,
        },
    }
}

Answer 1

Django 1.7 Databases docs 中概述了以下内容：

在以前的 Django 版本中，可以通过在 DATABASES 中的数据库配置的 OPTIONS 部分中设置自动提交键来启用数据库级别的自动提交。

从 Django 1.6 开始，默认开启自动提交。此配置被忽略，可以安全删除。

根据1.8 Release Notes，此功能已被删除。

如果您出于某种原因仍想保留该设置，只需将其移出OPTIONS：

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql_psycopg2',
        'HOST': 'localhost',
        'PORT': '5432',
        'NAME': 'bp_django_auth',
        'USER': 'postgres',
        'PASSWORD': 'abcd1234',
        'AUTOCOMMIT': True,
    }
}