Question

我正在开始一个全新的项目，其中涉及Flask + SQLAlchemy和pymysql。目前，基于模型创建表失败的原因如下：

导致错误的代码（main.py）中的行是：

app = Flask(__name__)
app.config['DEBUG'] = True
app.config['SQLALCHEMY_DATABASE_URI'] = 'mysql+pymysql://myapp:myapp@localhost/myapp'
db = SQLAlchemy(app)
class User(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    guid = db.Column(db.String(255), unique=True)
    def __init__(self):
        self.guid = str(uuid.uuid1())

db.create_all()

# Note: We don't need to call run() since our application is embedded within
# the App Engine WSGI application server.

@app.route('/')
def hello():
    """Return a friendly HTTP greeting."""
    return 'Hello World!'

@app.errorhandler(404)
def page_not_found(e):
    """Return a custom 404 error."""
    return 'Sorry, nothing at this URL.', 404

Traceback (most recent call last):
  File "/Users/myuserid/Documents/Development/google-cloud-sdk/platform/google_appengine/google/appengine/runtime/wsgi.py", line 240, in Handle
    handler = _config_handle.add_wsgi_middleware(self._LoadHandler())
  File "/Users/myuserid/Documents/Development/google-cloud-sdk/platform/google_appengine/google/appengine/runtime/wsgi.py", line 299, in _LoadHandler
    handler, path, err = LoadObject(self._handler)
  File "/Users/myuserid/Documents/Development/google-cloud-sdk/platform/google_appengine/google/appengine/runtime/wsgi.py", line 85, in LoadObject
    obj = __import__(path[0])
  File "/Users/myuserid/Documents/Development/myapp-server/main.py", line 9, in <module>
    db.create_all()
  File "/Users/myuserid/Documents/Development/myapp-server/lib/flask_sqlalchemy/__init__.py", line 895, in create_all
    self._execute_for_all_tables(app, bind, 'create_all')
  File "/Users/myuserid/Documents/Development/myapp-server/lib/flask_sqlalchemy/__init__.py", line 887, in _execute_for_all_tables
    op(bind=self.get_engine(app, bind), **extra)
  File "/Users/myuserid/Documents/Development/myapp-server/lib/sqlalchemy/sql/schema.py", line 3614, in create_all
    tables=tables)
  File "/Users/myuserid/Documents/Development/myapp-server/lib/sqlalchemy/engine/base.py", line 1850, in _run_visitor
    with self._optional_conn_ctx_manager(connection) as conn:
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/contextlib.py", line 17, in __enter__
    return self.gen.next()
  File "/Users/myuserid/Documents/Development/myapp-server/lib/sqlalchemy/engine/base.py", line 1843, in _optional_conn_ctx_manager
    with self.contextual_connect() as conn:
  File "/Users/myuserid/Documents/Development/myapp-server/lib/sqlalchemy/engine/base.py", line 2034, in contextual_connect
    self._wrap_pool_connect(self.pool.connect, None),
  File "/Users/myuserid/Documents/Development/myapp-server/lib/sqlalchemy/engine/base.py", line 2069, in _wrap_pool_connect
    return fn()
  File "/Users/myuserid/Documents/Development/myapp-server/lib/sqlalchemy/pool.py", line 376, in connect
    return _ConnectionFairy._checkout(self)
  File "/Users/myuserid/Documents/Development/myapp-server/lib/sqlalchemy/pool.py", line 708, in _checkout
    fairy = _ConnectionRecord.checkout(pool)
  File "/Users/myuserid/Documents/Development/myapp-server/lib/sqlalchemy/pool.py", line 480, in checkout
    rec = pool._do_get()
  File "/Users/myuserid/Documents/Development/myapp-server/lib/sqlalchemy/pool.py", line 1049, in _do_get
    self._dec_overflow()
  File "/Users/myuserid/Documents/Development/myapp-server/lib/sqlalchemy/util/langhelpers.py", line 60, in __exit__
    compat.reraise(exc_type, exc_value, exc_tb)
  File "/Users/myuserid/Documents/Development/myapp-server/lib/sqlalchemy/pool.py", line 1046, in _do_get
    return self._create_connection()
  File "/Users/myuserid/Documents/Development/myapp-server/lib/sqlalchemy/pool.py", line 323, in _create_connection
    return _ConnectionRecord(self)
  File "/Users/myuserid/Documents/Development/myapp-server/lib/sqlalchemy/pool.py", line 449, in __init__
    self.connection = self.__connect()
  File "/Users/myuserid/Documents/Development/myapp-server/lib/sqlalchemy/pool.py", line 602, in __connect
    connection = self.__pool._invoke_creator(self)
  File "/Users/myuserid/Documents/Development/myapp-server/lib/sqlalchemy/engine/strategies.py", line 97, in connect
    return dialect.connect(*cargs, **cparams)
  File "/Users/myuserid/Documents/Development/myapp-server/lib/sqlalchemy/engine/default.py", line 377, in connect
    return self.dbapi.connect(*cargs, **cparams)
  File "/Users/myuserid/Documents/Development/myapp-server/lib/pymysql/__init__.py", line 88, in Connect
    return Connection(*args, **kwargs)
  File "/Users/myuserid/Documents/Development/myapp-server/lib/pymysql/connections.py", line 644, in __init__
    self._connect()
  File "/Users/myuserid/Documents/Development/myapp-server/lib/pymysql/connections.py", line 837, in _connect
    self._get_server_information()
  File "/Users/myuserid/Documents/Development/myapp-server/lib/pymysql/connections.py", line 1048, in _get_server_information
    packet = self._read_packet()
  File "/Users/myuserid/Documents/Development/myapp-server/lib/pymysql/connections.py", line 882, in _read_packet
    packet_header = self._read_bytes(4)
  File "/Users/myuserid/Documents/Development/myapp-server/lib/pymysql/connections.py", line 899, in _read_bytes
    data = self._rfile.read(num_bytes)
  File "/Users/myuserid/Documents/Development/myapp-server/lib/pymysql/_socketio.py", line 64, in readinto
    n = e.args[0]
IndexError: tuple index out of range
INFO     2015-05-05 23:30:40,803 module.py:788] default: "GET / HTTP/1.1" 500 -

Flask上的PyMySql + SQLAlchemy：create_all失败

0 个答案: