使用 SQLAlchemy 和 cx_Oracle 连接到 oracle 服务器

Question

今天我来找你是因为我想将我的 oracle localhost 服务器连接到我的脚本。 所以我有以下代码：

import sqlalchemy
import cx_Oracle

connexion_string=str('oracle+cx_oracle://' + con['sql']['user'] + ':' + con['sql']['password'] + '@' + con['sql']['server'] + ':' + con['sql']['port'] + '/?service_name=' + con['sql']['database'])

try:
   engine = sqlalchemy.create_engine(connexion_string)
   conn = engine.connect()
except Exception as e:
   print(type(e))

使用此代码，我有以下错误：

<class 'sqlalchemy.exc.DatabaseError'>

我不知道为什么它不起作用，如果有人可以帮助我，那应该很好！

我正在使用SQLAlchemy 1.3.18和cx_Oracle 8.0.0以及python 3.8.3 （它也适用于 3.7.6）

祝你今天过得愉快 ！

Answer 1

我以这种方式使用sqlalchemy和cx_oracle ：

from sqlalchemy import create_engine
import cx_Oracle

host="myhost"
port=myport
sid='myservicename'
user='myuser'
password='mypassword'
sid = cx_Oracle.makedsn(host, port, service_name=sid)

cstr = 'oracle://{user}:{password}@{sid}'.format(
    user=user,
    password=password,
    sid=sid
)

engine =  create_engine(
    cstr,
    convert_unicode=False,
    pool_recycle=10,
    pool_size=50,
    echo=True,
    max_identifier_length=128
)

result = engine.execute('select * from dual')

for row in result:
    print (row)

C:\python>python mytest_sql.py
2020-08-12 14:14:12,136 INFO sqlalchemy.engine.base.Engine SELECT USER FROM DUAL
2020-08-12 14:14:12,137 INFO sqlalchemy.engine.base.Engine {}
2020-08-12 14:14:12,192 INFO sqlalchemy.engine.base.Engine SELECT CAST('test plain returns' AS VARCHAR(60 CHAR)) AS anon_1 FROM DUAL
2020-08-12 14:14:12,192 INFO sqlalchemy.engine.base.Engine {}
2020-08-12 14:14:12,247 INFO sqlalchemy.engine.base.Engine SELECT CAST('test unicode returns' AS VARCHAR2(60 CHAR)) AS anon_1 FROM DUAL
2020-08-12 14:14:12,248 INFO sqlalchemy.engine.base.Engine {}
2020-08-12 14:14:12,303 INFO sqlalchemy.engine.base.Engine SELECT CAST('test nvarchar2 returns' AS NVARCHAR2(60)) AS anon_1 FROM DUAL
2020-08-12 14:14:12,304 INFO sqlalchemy.engine.base.Engine {}
2020-08-12 14:14:12,383 INFO sqlalchemy.engine.base.Engine select value from nls_session_parameters where parameter = 'NLS_NUMERIC_CHARACTERS'
2020-08-12 14:14:12,383 INFO sqlalchemy.engine.base.Engine {}
2020-08-12 14:14:12,490 INFO sqlalchemy.engine.base.Engine select * from dual
2020-08-12 14:14:12,492 INFO sqlalchemy.engine.base.Engine {}
('X',)

C:\python>