mysql 无法使用sqlalchemy创建表

bq8i3lrv  于 5个月前  发布在  Mysql
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我试图通过使用sqlalchemy创建mysql数据库，并运行到这个错误。添加一个错误的完整追溯：

Traceback (most recent call last):
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\sqlalchemy\engine\base.py", line 145, in __init__
    self._dbapi_connection = engine.raw_connection()
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\sqlalchemy\engine\base.py", line 3292, in raw_connection
    return self.pool.connect()
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\sqlalchemy\pool\base.py", line 452, in connect
    return _ConnectionFairy._checkout(self)
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\sqlalchemy\pool\base.py", line 1269, in _checkout
    fairy = _ConnectionRecord.checkout(pool)
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\sqlalchemy\pool\base.py", line 716, in checkout
    rec = pool._do_get()
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\sqlalchemy\pool\impl.py", line 169, in _do_get
    with util.safe_reraise():
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\sqlalchemy\util\langhelpers.py", line 146, in __exit__
    raise exc_value.with_traceback(exc_tb)
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\sqlalchemy\pool\impl.py", line 167, in _do_get
    return self._create_connection()
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\sqlalchemy\pool\base.py", line 393, in _create_connection
    return _ConnectionRecord(self)
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\sqlalchemy\pool\base.py", line 678, in __init__
    self.__connect()
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\sqlalchemy\pool\base.py", line 902, in __connect
    with util.safe_reraise():
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\sqlalchemy\util\langhelpers.py", line 146, in __exit__
    raise exc_value.with_traceback(exc_tb)
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\sqlalchemy\pool\base.py", line 898, in __connect
    self.dbapi_connection = connection = pool._invoke_creator(self)
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\sqlalchemy\engine\create.py", line 637, in connect
    return dialect.connect(*cargs, **cparams)
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\sqlalchemy\engine\default.py", line 616, in connect
    return self.loaded_dbapi.connect(*cargs, **cparams)
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\pymysql\connections.py", line 353, in __init__
    self.connect()
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\pymysql\connections.py", line 633, in connect
    self._request_authentication()
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\pymysql\connections.py", line 932, in _request_authentication
    auth_packet = _auth.caching_sha2_password_auth(self, auth_packet)
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\pymysql\_auth.py", line 239, in caching_sha2_password_auth
    pkt = conn._read_packet()
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\pymysql\connections.py", line 725, in _read_packet
    packet.raise_for_error()
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\pymysql\protocol.py", line 221, in raise_for_error
    err.raise_mysql_exception(self._data)
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\pymysql\err.py", line 143, in raise_mysql_exception
    raise errorclass(errno, errval)
pymysql.err.OperationalError: (1049, "Unknown database 'books'")
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
  File "C:\Program Files\JetBrains\PyCharm 2023.3\plugins\python\helpers\pydev\pydevconsole.py", line 364, in runcode
    coro = func()
  File "<input>", line 1, in <module>
  File "C:\Program Files\JetBrains\PyCharm 2023.3\plugins\python\helpers\pydev\_pydev_bundle\pydev_umd.py", line 197, in runfile
    pydev_imports.execfile(filename, global_vars, local_vars)  # execute the script
  File "C:\Program Files\JetBrains\PyCharm 2023.3\plugins\python\helpers\pydev\_pydev_imps\_pydev_execfile.py", line 18, in execfile
    exec(compile(contents+"\n", file, 'exec'), glob, loc)
  File "C:\Users\baron\Python_Darbai\Turing_college\GIT\Sprint_3\dbaron-DE1.3\test_db_creaton.py", line 183, in <module>
    db_manager.create_database()
  File "C:\Users\baron\Python_Darbai\Turing_college\GIT\Sprint_3\dbaron-DE1.3\test_db_creaton.py", line 29, in create_database
    self.session.execute(create_database_query)
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\sqlalchemy\orm\session.py", line 2308, in execute
    return self._execute_internal(
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\sqlalchemy\orm\session.py", line 2180, in _execute_internal
    conn = self._connection_for_bind(bind)
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\sqlalchemy\orm\session.py", line 2047, in _connection_for_bind
    return trans._connection_for_bind(engine, execution_options)
  File "<string>", line 2, in _connection_for_bind
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\sqlalchemy\orm\state_changes.py", line 139, in _go
    ret_value = fn(self, *arg, **kw)
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\sqlalchemy\orm\session.py", line 1143, in _connection_for_bind
    conn = bind.connect()
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\sqlalchemy\engine\base.py", line 3268, in connect
    return self._connection_cls(self)
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\sqlalchemy\engine\base.py", line 147, in __init__
    Connection._handle_dbapi_exception_noconnection(
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\sqlalchemy\engine\base.py", line 2430, in _handle_dbapi_exception_noconnection
    raise sqlalchemy_exception.with_traceback(exc_info[2]) from e
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\sqlalchemy\engine\base.py", line 145, in __init__
    self._dbapi_connection = engine.raw_connection()
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\sqlalchemy\engine\base.py", line 3292, in raw_connection
    return self.pool.connect()
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\sqlalchemy\pool\base.py", line 452, in connect
    return _ConnectionFairy._checkout(self)
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\sqlalchemy\pool\base.py", line 1269, in _checkout
    fairy = _ConnectionRecord.checkout(pool)
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\sqlalchemy\pool\base.py", line 716, in checkout
    rec = pool._do_get()
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\sqlalchemy\pool\impl.py", line 169, in _do_get
    with util.safe_reraise():
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\sqlalchemy\util\langhelpers.py", line 146, in __exit__
    raise exc_value.with_traceback(exc_tb)
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\sqlalchemy\pool\impl.py", line 167, in _do_get
    return self._create_connection()
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\sqlalchemy\pool\base.py", line 393, in _create_connection
    return _ConnectionRecord(self)
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\sqlalchemy\pool\base.py", line 678, in __init__
    self.__connect()
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\sqlalchemy\pool\base.py", line 902, in __connect
    with util.safe_reraise():
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\sqlalchemy\util\langhelpers.py", line 146, in __exit__
    raise exc_value.with_traceback(exc_tb)
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\sqlalchemy\pool\base.py", line 898, in __connect
    self.dbapi_connection = connection = pool._invoke_creator(self)
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\sqlalchemy\engine\create.py", line 637, in connect
    return dialect.connect(*cargs, **cparams)
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\sqlalchemy\engine\default.py", line 616, in connect
    return self.loaded_dbapi.connect(*cargs, **cparams)
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\pymysql\connections.py", line 353, in __init__
    self.connect()
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\pymysql\connections.py", line 633, in connect
    self._request_authentication()
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\pymysql\connections.py", line 932, in _request_authentication
    auth_packet = _auth.caching_sha2_password_auth(self, auth_packet)
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\pymysql\_auth.py", line 239, in caching_sha2_password_auth
    pkt = conn._read_packet()
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\pymysql\connections.py", line 725, in _read_packet
    packet.raise_for_error()
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\pymysql\protocol.py", line 221, in raise_for_error
    err.raise_mysql_exception(self._data)
  File "C:\Users\baron\AppData\Local\Programs\Python\Python310\lib\site-packages\pymysql\err.py", line 143, in raise_mysql_exception
    raise errorclass(errno, errval)
sqlalchemy.exc.OperationalError: (pymysql.err.OperationalError) (1049, "Unknown database 'books'")
(Background on this error at: https://sqlalche.me/e/20/e3q8)

字符串
所有数据库凭据都在. env文件中。添加代码片段，可能有问题：

from sqlalchemy import Column, Integer, String, ForeignKey, Float
from sqlalchemy.orm import relationship, declarative_base
import os
from dotenv import load_dotenv
from sqlalchemy import create_engine, text
from sqlalchemy.orm import sessionmaker
import pymysql

Base = declarative_base()

class DatabaseManager:
    def __init__(self):
        load_dotenv()

        self.root_username = os.getenv("ROOT_USERNAME")
        self.root_password = os.getenv("ROOT_PASSWORD")
        self.new_database = os.getenv("NEW_DATABASE")

        if None in [self.root_username, self.root_password, self.new_database]:
            raise ValueError("Missing environment variables")

        self.DB_URI = f"mysql+pymysql://{self.root_username}:{self.root_password}@localhost/{self.new_database}"
        self.engine = create_engine(self.DB_URI, echo=True)
        self.Session = sessionmaker(bind=self.engine)
        self.session = self.Session()

    def create_database(self):
        create_database_query = text(f"CREATE DATABASE IF NOT EXISTS {self.new_database}")
        self.session.execute(create_database_query)
        self.session.commit()

    def create_tables(self):
        Base.metadata.create_all(self.engine)

    def close_connection(self):
        self.session.close()

型
我的这部分代码有什么问题（没有全部添加，因为它太长了，而且基本上只有表）？

mysql

1条答案

按热度按时间
mwg9r5ms

mwg9r5ms1#

在运行这段代码之前，您必须创建数据库books。SQLAlchemy不会为您创建数据库，它认为数据库已经存在

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