使用sqlalchemy.engine.url.URL为mssql + pyodbc建立连接URL

Question

我正在尝试通过SQLAlchemy连接到MSSql服务器。这是我的带有伪造凭据的代码（ 显然不是我的真实凭据 ）。

编码…

credentials = {
'username'  : 'SPOTTER_xyz_ACC',
'password'  : '123Goodbye2016!@#',
'host'      : 'MARYLQLT01',
'database'  : 'LRS_DUS',
'port'      : '1560'}

connect_url = sqlalchemy.engine.url.URL(
    'mssql+pyodbc',
    username=credentials['username'],
    password=credentials['password'],
    host=credentials['host'],
    port=credentials['port'],
    query=dict(service_name=credentials['database']))

engine = create_engine(connect_url)
connection=engine.connect()

这是我得到的.pyodbc错误。

(pyodbc.Error) ('IM002', '[IM002] [Microsoft][ODBC Driver Manager] Data source
name not found and no default driver specified (0) (SQLDriverConnect)')

额外细节

但是，这是很奇怪的…如果建立pyodbc连接并使用Pandas.read_sql，那么我可以毫无错误地获取数据。所以我不明白为什么会出现“
pyodbc”错误？

connection=pyodbc.connect(\
                          'Driver={SQL Server}; \
                          Server=MARYLQLT01; \
                          Database=LRS_DUS; \
                          UID=SPOTTER_xyz_ACC; \
                          PWD=123Goodbye2016!@#')

stmt='select * from PD_SC_All'
df=pd.read_sql(stmt,connection)

然后我可以看到数据框。

那么，(pyodbc.Error)当我尝试连接SQLAlchemy时为什么得到了？

系统信息

Windows 7
SQLAlchemy: 1.1.11
pyodbc: 4.0.16

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Answer 1

如SQLAlchemy文档中所述，用于mssql+pyodbc连接

基于主机名的连接 不是首选 ，但受支持。必须明确指定ODBC驱动程序名称：

engine =

create_engine(“mssql+pyodbc://scott:tiger@myhost:port/databasename?driver=SQL+Server+Native+Client+10.0”)

对于

credentials = {
    'username': 'scott',
    'password': 'tiger',
    'host': 'myhost',
    'database': 'databasename',
    'port': '1560'}

您的陈述

connect_url = sqlalchemy.engine.url.URL(
    'mssql+pyodbc',
    username=credentials['username'],
    password=credentials['password'],
    host=credentials['host'],
    port=credentials['port'],
    query=dict(service_name=credentials['database']))

产生 connect_url

mssql+pyodbc://scott:tiger@myhost:1560?service_name=databasename

您真正需要的是

connect_url = sqlalchemy.engine.url.URL(
    'mssql+pyodbc',
    username=credentials['username'],
    password=credentials['password'],
    host=credentials['host'],
    port=credentials['port'],
    database=credentials['database'],
    query=dict(driver='SQL+Server'))

产生

mssql+pyodbc://scott:tiger@myhost:1560/databasename?driver=SQL+Server