我一直在 Linux 上使用 django-pyodbc-azure 以及 pydobc、FreeTDS 和 unixODBC 将 Django 连接到 SQL Server 2014。我在一个运行良好的应用程序中遇到了这个问题，我无法调试它。为了重现这个问题，我启动了一个全新的 Django 应用程序来让事情变得简单。这是我的虚拟环境:

(azuretest)[vagrant@vagrant azuretest]$ pip freeze
Django==1.8.6
django-pyodbc-azure==1.8.3.0
pyodbc==3.0.10

这是我连接到 SQL Server 的数据库配置:

DATABASES = {
    'default': {
        'ENGINE': 'sql_server.pyodbc',
        'HOST': 'myserver.com',
        'PORT': '1433',
        'NAME': 'my_db',
        'USER': 'my_db_user',
        'PASSWORD': 'mypw',
        'AUTOCOMMIT': True,
        'OPTIONS': {
            'driver': 'FreeTDS',
            'autocommit': True,
            'unicode_results': True,
            'host_is_server': True,
            'extra_params': 'tds_version=7.2',
        },
    },
}

然后我创建了一个简单的 models.py:

class TestTemp(models.Model):
    tempdate = models.DateField()

这个设置在一个相当复杂的 Django 项目中运行良好，它仍然可以选择到同一个数据库。但是，每当我尝试进行更新或迁移时，我都会收到此错误:

(azuretest)[vagrant@vagrant azuretest]$ ./manage.py migrate home
Operations to perform:
  Apply all migrations: home
Running migrations:
  Rendering model states... DONE
  Applying home.0001_initial...Traceback (most recent call last):
  File "/home/vagrant/.virtualenvs/azuretest/lib/python3.4/site-packages/sql_server/pyodbc/base.py", line 389, in _set_aut
ocommit
    self.connection.rollback()
pyodbc.Error: ('HY000', 'The driver did not supply an error!')

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "./manage.py", line 10, in <module>
    execute_from_command_line(sys.argv)
  File "/home/vagrant/.virtualenvs/azuretest/lib/python3.4/site-packages/django/core/management/__init__.py", line 354, in
 execute_from_command_line
    utility.execute()
  File "/home/vagrant/.virtualenvs/azuretest/lib/python3.4/site-packages/django/core/management/__init__.py", line 346, in
 execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/home/vagrant/.virtualenvs/azuretest/lib/python3.4/site-packages/django/core/management/base.py", line 394, in run
_from_argv
    self.execute(*args, **cmd_options)
  File "/home/vagrant/.virtualenvs/azuretest/lib/python3.4/site-packages/django/core/management/base.py", line 445, in exe
cute
    output = self.handle(*args, **options)
  File "/home/vagrant/.virtualenvs/azuretest/lib/python3.4/site-packages/django/core/management/commands/migrate.py", line
 222, in handle
    executor.migrate(targets, plan, fake=fake, fake_initial=fake_initial)
  File "/home/vagrant/.virtualenvs/azuretest/lib/python3.4/site-packages/django/db/migrations/executor.py", line 110, in m
igrate
    self.apply_migration(states[migration], migration, fake=fake, fake_initial=fake_initial)
  File "/home/vagrant/.virtualenvs/azuretest/lib/python3.4/site-packages/django/db/migrations/executor.py", line 154, in a
pply_migration
    self.recorder.record_applied(migration.app_label, migration.name)
  File "/home/vagrant/.virtualenvs/azuretest/lib/python3.4/site-packages/django/db/migrations/recorder.py", line 67, in re
cord_applied
    self.migration_qs.create(app=app, name=name)
  File "/home/vagrant/.virtualenvs/azuretest/lib/python3.4/site-packages/django/db/models/query.py", line 348, in create
    obj.save(force_insert=True, using=self.db)
  File "/home/vagrant/.virtualenvs/azuretest/lib/python3.4/site-packages/django/db/models/base.py", line 734, in save
    force_update=force_update, update_fields=update_fields)
  File "/home/vagrant/.virtualenvs/azuretest/lib/python3.4/site-packages/django/db/models/base.py", line 759, in save_base

    with transaction.atomic(using=using, savepoint=False):
  File "/home/vagrant/.virtualenvs/azuretest/lib/python3.4/site-packages/django/db/transaction.py", line 186, in __enter__

    connection.set_autocommit(False)
  File "/home/vagrant/.virtualenvs/azuretest/lib/python3.4/site-packages/django/db/backends/base/base.py", line 295, in se
t_autocommit
    self._set_autocommit(autocommit)
  File "/home/vagrant/.virtualenvs/azuretest/lib/python3.4/site-packages/sql_server/pyodbc/base.py", line 390, in _set_aut
ocommit
    self.connection.autocommit = autocommit
  File "/home/vagrant/.virtualenvs/azuretest/lib/python3.4/site-packages/django/db/utils.py", line 98, in __exit__
    six.reraise(dj_exc_type, dj_exc_value, traceback)
  File "/home/vagrant/.virtualenvs/azuretest/lib/python3.4/site-packages/django/utils/six.py", line 658, in reraise
    raise value.with_traceback(tb)
  File "/home/vagrant/.virtualenvs/azuretest/lib/python3.4/site-packages/sql_server/pyodbc/base.py", line 389, in _set_aut
ocommit
    self.connection.rollback()
django.db.utils.Error: ('HY000', 'The driver did not supply an error!')

奇怪的是，它成功地在 SQL Server ([home_testtemp]) 中创建了表，并且似乎在不必要的回滚时出错。关于进一步调试或解决问题的最佳方法的任何想法？当我直接针对使用此用户名和密码登录的数据库运行 ./manage.py sqlmigrate home 的 SQL 输出时，它工作正常。

提前致谢。

更新 1:这不是一个很好的修复，但解决了在不应该调用回滚时似乎出现的问题。此更改是在 django-pyodbc-azure 中 base.py 的第 389 行附近进行的:

这很丑陋并且摆脱了保护措施，但同时可以使事情正常进行。修改 django-pyodbc-azure 中第 389 行附近的 base.py:

def _set_autocommit(self, autocommit):
        self.connection.commit()

#        with self.wrap_database_errors:
#            if autocommit:
#                self.connection.commit()
#            else:
#                self.connection.rollback()
#            self.connection.autocommit = autocommit

显然，仍在寻找实际的修复方法，而不是黑客攻击和根本原因。

更新 2:将上面更新 1 中所做的更改撤销到原始的 django-pyodbc。然后在设置中，将 tds_version 更改为 7.0 或 7.1。有用。如果将其更改为 7.2 或 7.3，它就会中断。这可能是 SQL Server 2008 中可用的新 DATE 字段的问题吗？无论哪种方式，一个临时解决方案是恢复到 TDS 版本 7.1，这显然是对修复有用的信息。

最佳答案

新版本的 django-pyodbc-azure 已经发布，它为我解决了这个问题(谢谢你，Michaya)。要修复它，只需升级:

pip install django-pyodbc-azure==1.8.6

...并在必要时更新您的需求文件。详情在这里:https://github.com/michiya/django-pyodbc-azure/issues/46

关于python - 先前工作配置的 django-pyodbc-azure 回滚错误 - 第 389 行，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/33673470/