Question

我正在AWS的Ubuntu 18.04 Lightsail实例中工作。当我在python3中运行以下代码时，出现以下错误。除了最后一个Base.metadata.create_all(engine)之外，此脚本中的每一行都运行良好。此行产生以下错误。

import os
import sys
from sqlalchemy import Column, ForeignKey, Integer, String
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import relationship
from sqlalchemy import create_engine
from support_functions import get_input_args
Base = declarative_base()
engine = create_engine('sqlite:///db_test.db')
Base.metadata.create_all(engine)

我得到的错误是：

Traceback (most recent call last):
  File "/usr/local/lib/python3.6/dist-packages/sqlalchemy/engine/base.py", line 2275, in _wrap_pool_connect
    return fn()
  File "/usr/local/lib/python3.6/dist-packages/sqlalchemy/pool/base.py", line 363, in connect
    return _ConnectionFairy._checkout(self)
  File "/usr/local/lib/python3.6/dist-packages/sqlalchemy/pool/base.py", line 760, in _checkout
    fairy = _ConnectionRecord.checkout(pool)
  File "/usr/local/lib/python3.6/dist-packages/sqlalchemy/pool/base.py", line 492, in checkout
    rec = pool._do_get()
  File "/usr/local/lib/python3.6/dist-packages/sqlalchemy/pool/impl.py", line 238, in _do_get
    return self._create_connection()
  File "/usr/local/lib/python3.6/dist-packages/sqlalchemy/pool/base.py", line 308, in _create_connection
    return _ConnectionRecord(self)
  File "/usr/local/lib/python3.6/dist-packages/sqlalchemy/pool/base.py", line 437, in __init__
    self.__connect(first_connect_check=True)
  File "/usr/local/lib/python3.6/dist-packages/sqlalchemy/pool/base.py", line 639, in __connect
    connection = pool._invoke_creator(self)
  File "/usr/local/lib/python3.6/dist-packages/sqlalchemy/engine/strategies.py", line 114, in connect
    return dialect.connect(*cargs, **cparams)
  File "/usr/local/lib/python3.6/dist-packages/sqlalchemy/engine/default.py", line 453, in connect
    return self.dbapi.connect(*cargs, **cparams)
sqlite3.OperationalError: unable to open database file

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

Traceback (most recent call last):
File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python3.6/dist-packages/sqlalchemy/sql/schema.py", line 4294, in create_all
    ddl.SchemaGenerator, self, checkfirst=checkfirst, tables=tables
  File "/usr/local/lib/python3.6/dist-packages/sqlalchemy/engine/base.py", line 2045, in _run_visitor
    with self._optional_conn_ctx_manager(connection) as conn:
  File "/usr/lib/python3.6/contextlib.py", line 81, in __enter__
    return next(self.gen)
  File "/usr/local/lib/python3.6/dist-packages/sqlalchemy/engine/base.py", line 2037, in _optional_conn_ctx_manager
    with self._contextual_connect() as conn:
  File "/usr/local/lib/python3.6/dist-packages/sqlalchemy/engine/base.py", line 2239, in _contextual_connect
    self._wrap_pool_connect(self.pool.connect, None),
  File "/usr/local/lib/python3.6/dist-packages/sqlalchemy/engine/base.py", line 2279, in _wrap_pool_connect
    e, dialect, self
  File "/usr/local/lib/python3.6/dist-packages/sqlalchemy/engine/base.py", line 1544, in _handle_dbapi_exception_noconnection
    util.raise_from_cause(sqlalchemy_exception, exc_info)
  File "/usr/local/lib/python3.6/dist-packages/sqlalchemy/util/compat.py", line 398, in raise_from_cause
    reraise(type(exception), exception, tb=exc_tb, cause=cause)
  File "/usr/local/lib/python3.6/dist-packages/sqlalchemy/util/compat.py", line 152, in reraise
    raise value.with_traceback(tb)
  File "/usr/local/lib/python3.6/dist-packages/sqlalchemy/engine/base.py", line 2275, in _wrap_pool_connect
    return fn()
  File "/usr/local/lib/python3.6/dist-packages/sqlalchemy/pool/base.py", line 363, in connect
    return _ConnectionFairy._checkout(self)
  File "/usr/local/lib/python3.6/dist-packages/sqlalchemy/pool/base.py", line 760, in _checkout
    fairy = _ConnectionRecord.checkout(pool)
  File "/usr/local/lib/python3.6/dist-packages/sqlalchemy/pool/base.py", line 492, in checkout
    rec = pool._do_get()
  File "/usr/local/lib/python3.6/dist-packages/sqlalchemy/pool/impl.py", line 238, in _do_get
    return self._create_connection()
  File "/usr/local/lib/python3.6/dist-packages/sqlalchemy/pool/base.py", line 308, in _create_connection
    return _ConnectionRecord(self)
  File "/usr/local/lib/python3.6/dist-packages/sqlalchemy/pool/base.py", line 437, in __init__
    self.__connect(first_connect_check=True)
  File "/usr/local/lib/python3.6/dist-packages/sqlalchemy/pool/base.py", line 639, in __connect
    connection = pool._invoke_creator(self)
  File "/usr/local/lib/python3.6/dist-packages/sqlalchemy/engine/strategies.py", line 114, in connect
    return dialect.connect(*cargs, **cparams)
  File "/usr/local/lib/python3.6/dist-packages/sqlalchemy/engine/default.py", line 453, in connect
    return self.dbapi.connect(*cargs, **cparams)
sqlalchemy.exc.OperationalError: (sqlite3.OperationalError) unable to open database file
(Background on this error at: http://sqlalche.me/e/e3q8)

Answer 1

SQLALCHEMY_DATABASE_URI = os.environ.get('DATABASE_URL') or 'sqlite://' + os.path.join(basedir, 'app.db')

将'sqlite：//'更改为'sqlite：///'

sqlalchemy.exc.OperationalError：（sqlite3.OperationalError）尝试创建数据库时无法打开数据库文件错误

1 个答案: