Microsoft Azure Data warehouse and SqlAlchemy

问题:

I am trying to use python's sqlalchemy library for connecting to microsoft azure data warehouse. and receiving the following error:

 (pyodbc.Error) ('HY000', '[HY000] [Microsoft][ODBC SQL Server Driver][SQL Server]Client driver version is not supported. (46722) (SQLDriverConnect); [HY000] [Microsoft][ODBC SQL Server Driver][SQL Server]Client driver version is not supported. (46722)')

my code for windows connection:

import sqlalchemy
user_name = 'userName'
password = 'password'
uri = 'sqlServerName'
db_name = 'SQLDBName'
db_prefix = 'mssql+pyodbc://'
db_driver = '{SQL Server}'
connection_string = "{db_prefix}{user_name}:{password}@{uri}/{db_name}?Driver={driver}".format(
                db_prefix=db_prefix, user_name=user_name, password=password, uri=uri, db_name=db_name,
                driver=db_driver)
engine = sqlalchemy.engine.create_engine(connection_string, echo=echo, pool_size=20,
                                                          max_overflow=100)
engine.connect()  # throws the error

Thanks in advance!

回答1:

According to your code, it seems that the issue was caused by using the incorrect Driver={SQL Server}.

On Azure portal, you can get the connection string via follow the steps as the figure below.

The correct odbc driver name should be Driver={ODBC Driver 13 for SQL Server}. Meanwhile, please follow the tutorial to install the correct version 3.1.1 of pyodbc for your current environment.

Here is my testing code as below.

import sqlalchemy

connection_string = "mssql+pyodbc://<user>@<server-host>:<password>@<server-host>.database.windows.net:1433/<database>?driver=ODBC+Driver+13+for+SQL+Server"
engine = sqlalchemy.engine.create_engine(connection_string)
engine.connect()

Or

import sqlalchemy
import urllib

params = urllib.quote_plus("Driver={ODBC Driver 13 for SQL Server};Server=<server-host>.database.windows.net,1433;Database=<database>;Uid=<user>@<server-host>;Pwd=<password>;Encrypt=yes;TrustServerCertificate=no;Connection Timeout=30;")
engine = sqlalchemy.engine.create_engine("mssql+pyodbc:///?odbc_connect=%s" % params)
engine.connect()

I got an exception sqlalchemy.exc.ProgrammingError: (pyodbc.ProgrammingError) ('42000', "[42000] [Microsoft][ODBC Driver 13 for SQL Server][SQL Server]Catalog view 'dm_exec_sessions' is not supported in this version. (104385) (SQLExecDirectW)") when I ran the codes above, but it seems not affect working.

And I test the code below only using pyodbc, it works perfectly.

import pyodbc
cnxn = pyodbc.connect("Driver={ODBC Driver 13 for SQL Server};Server=<server-host>.database.windows.net,1433;Database=<database>;Uid=<user>@<server-host>;Pwd=<password>;Encrypt=yes;TrustServerCertificate=no;Connection Timeout=30;")
cursor = cnxn.cursor()
cursor.execute("select @@VERSION")
row = cursor.fetchone()
if row:
    print row

Output:

(u'Microsoft Azure SQL Data Warehouse - 10.0.8529.1 Jan 13 2017 22:49:03 Copyright (c) Microsoft Corporation', )