带Flas的url_value_预处理器中的Peewee“连接已打开”

Question

我要做的是检查传递给route方法的子域值，就像解释的here

每当我访问panel蓝图时，都会收到以下错误：peewee.OperationalError: Connection already open

这就是我在主应用程序文件中初始化数据库的方法。在

flask_db = FlaskDB(app)
database = flask_db.database

问题代码似乎是

^{pr2}$

完整的源代码可以在Gitlab上找到

__init__.py是主应用程序文件。panel/__init__.py有问题的代码。这是我收到的完整回溯：

Traceback (most recent call last):
  File "/home/marten/Projects/Comp/server/venv/lib/python3.6/site-packages/flask/app.py", line 1997, in __call__
    return self.wsgi_app(environ, start_response)
  File "/home/marten/Projects/Comp/server/venv/lib/python3.6/site-packages/flask/app.py", line 1985, in wsgi_app
    response = self.handle_exception(e)
  File "/home/marten/Projects/Comp/server/venv/lib/python3.6/site-packages/flask/app.py", line 1540, in handle_exception
    reraise(exc_type, exc_value, tb)
  File "/home/marten/Projects/Comp/server/venv/lib/python3.6/site-packages/flask/_compat.py", line 33, in reraise
    raise value
  File "/home/marten/Projects/Comp/server/venv/lib/python3.6/site-packages/flask/app.py", line 1982, in wsgi_app
    response = self.full_dispatch_request()
  File "/home/marten/Projects/Comp/server/venv/lib/python3.6/site-packages/flask/app.py", line 1614, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "/home/marten/Projects/Comp/server/venv/lib/python3.6/site-packages/flask/app.py", line 1517, in handle_user_exception
    reraise(exc_type, exc_value, tb)
  File "/home/marten/Projects/Comp/server/venv/lib/python3.6/site-packages/flask/_compat.py", line 33, in reraise
    raise value
  File "/home/marten/Projects/Comp/server/venv/lib/python3.6/site-packages/flask/app.py", line 1610, in full_dispatch_request
    rv = self.preprocess_request()
  File "/home/marten/Projects/Comp/server/venv/lib/python3.6/site-packages/flask/app.py", line 1831, in preprocess_request
    rv = func()
  File "/home/marten/Projects/Comp/server/venv/lib/python3.6/site-packages/playhouse/flask_utils.py", line 171, in connect_db
    self.database.connect()
  File "/home/marten/Projects/Comp/server/venv/lib/python3.6/site-packages/peewee.py", line 3679, in connect
    raise OperationalError('Connection already open')
peewee.OperationalError: Connection already open

我不知道额外的连接是从哪里来的。它似乎是由客户端.select（）查询。在

---

编辑： 这里的代码

def get_or_404(client):
    app.logger.debug(database.get_tables())
    cli = Client.select().where(Client.subdomain == client)

生成此响应

--------------------------------------------------------------------------------
DEBUG in models [/home/marten/Projects/Comp/server/app/panel/models.py:14]:
['client', 'role', 'user', 'userroles']
--------------------------------------------------------------------------------
127.0.0.1 - - [17/Aug/2017 14:57:31] "GET / HTTP/1.1" 500 -
Traceback (most recent call last):
  File "/home/marten/Projects/Comp/server/venv/lib/python3.6/site-packages/flask/app.py", line 1997, in __call__
    return self.wsgi_app(environ, start_response)
  File "/home/marten/Projects/Comp/server/venv/lib/python3.6/site-packages/flask/app.py", line 1985, in wsgi_app
    response = self.handle_exception(e)
  File "/home/marten/Projects/Comp/server/venv/lib/python3.6/site-packages/flask/app.py", line 1540, in handle_exception
    reraise(exc_type, exc_value, tb)
  File "/home/marten/Projects/Comp/server/venv/lib/python3.6/site-packages/flask/_compat.py", line 33, in reraise
    raise value
  File "/home/marten/Projects/Comp/server/venv/lib/python3.6/site-packages/flask/app.py", line 1982, in wsgi_app
    response = self.full_dispatch_request()
  File "/home/marten/Projects/Comp/server/venv/lib/python3.6/site-packages/flask/app.py", line 1614, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "/home/marten/Projects/Comp/server/venv/lib/python3.6/site-packages/flask/app.py", line 1517, in handle_user_exception
    reraise(exc_type, exc_value, tb)
  File "/home/marten/Projects/Comp/server/venv/lib/python3.6/site-packages/flask/_compat.py", line 33, in reraise
    raise value
  File "/home/marten/Projects/Comp/server/venv/lib/python3.6/site-packages/flask/app.py", line 1610, in full_dispatch_request
    rv = self.preprocess_request()
  File "/home/marten/Projects/Comp/server/venv/lib/python3.6/site-packages/flask/app.py", line 1831, in preprocess_request
    rv = func()
  File "/home/marten/Projects/Comp/server/venv/lib/python3.6/site-packages/playhouse/flask_utils.py", line 171, in connect_db
    self.database.connect()
  File "/home/marten/Projects/Comp/server/venv/lib/python3.6/site-packages/peewee.py", line 3679, in connect
    raise OperationalError('Connection already open')
peewee.OperationalError: Connection already open

如您所见，数据库实际上已连接，并且客户机表可用。在

---

编辑2： 好吧，我刚发现很显然database.get_tables()就会导致这个错误。但是，该代码确实从数据库中获取所有表。。。在

在初始化数据库之前，url_value_preprocessor是否运行？这会很奇怪，因为我在初始化数据库后导入了调用这个decorator的对象。在