在预连接参数中将Azure SQL DB的Azure AD令牌传递给SQLAlchemy create_engine（）

Question

我想通过带有AD令牌的SQLAlchemy连接到Azure SQL数据库。

我已经遵循https://github.com/felipefandrade/azuresqlspn，并且可以成功地使用此方法进行连接。但是，我想扩展它并使用SQLAlchemy来管理连接。

from os import environ
import struct
import adal
from sqlalchemy import create_engine
import pyodbc

clientSecret = environ.get('clientSecret')
clientID = environ.get('clientID')
tenantID =  environ.get('tenantID')
authorityHostUrl = "https://login.microsoftonline.com"
authority_url = authorityHostUrl + '/' + tenantID
resource = "https://database.windows.net/"
context = adal.AuthenticationContext(authority_url, api_version=None)

token = context.acquire_token_with_client_credentials(
    resource,
    clientID,
    clientSecret)


tokenb = bytes(token["accessToken"], "UTF-8")
exptoken = b''

for i in tokenb:
    exptoken += bytes({i})
    exptoken += bytes(1)

tokenstruct = struct.pack("=i", len(exptoken)) + exptoken

driver = "Driver={ODBC Driver 17 for SQL Server}"
server = ";SERVER={0}".format(environ.get('server'))
database = ";DATABASE={0}".format(environ.get('database'))

connString = driver + server + database

SQL_COPT_SS_ACCESS_TOKEN = 1256
conn = pyodbc.connect(connString, attrs_before={SQL_COPT_SS_ACCESS_TOKEN:tokenstruct})

cursor = conn.cursor()
cursor.execute("SELECT TOP 20 ID, Name FROM [Table1]")
row = cursor.fetchone()
print("######")
print("Using pyodbc directly - This works")
while row:
    print (str(row[0]) + " " + str(row[1]))
    row = cursor.fetchone()

print("#####")
print("Connecting via sqlalchemy - This doesn't work")
SAconnString = "mssql+pyodbc://<server>.database.windows.net/<database>?driver=ODBC+Driver+17+for+SQL+Server"
db = create_engine(SAconnString, connect_args={'attrs_before': {SQL_COPT_SS_ACCESS_TOKEN:tokenstruct}})

SAconn = db.connect()
result = SAconn.execute("SELECT TOP 20 ID, Name FROM [Table1]")
for row in result:
    print(row['ID'] + " " + row['Name'])

如代码中所述，可以使用pyodbc.connect()方法。但是，使用SQLAlchemy我收到错误FA005] [Microsoft][ODBC Driver 17 for SQL Server]Cannot use Access Token with any of the following options: Authentication, Integrated Security, User, Password。在我看来，connect_args选项正在传递令牌，但其他选项也正在传递。如何获得SQLAlchemy正确将AD令牌传递给pyodbc？

Answer 1

需要使用urllib显式发送PyODBC连接字符串。

connString = driver + server + database
params = urllib.parse.quote(connString)
db = create_engine("mssql+pyodbc:///?odbc_connect={0}".format(params), connect_args={'attrs_before': {SQL_COPT_SS_ACCESS_TOKEN:tokenstruct}})

Answer 2

如何使用SQLAlchemy编写此代码：

import sqlalchemy
import urllib
import pyodbc


params = urllib.parse.quote_plus("Driver={ODBC Driver 13 for SQL Server};Server=tcp:***.database.windows.net,1433;Database=Mydatabase;Uid=ServerAdmin@***;Pwd=***;Encrypt=yes;TrustServerCertificate=no;Connection Timeout=30;")

engine = sqlalchemy.create_engine("mssql+pyodbc:///?odbc_connect=%s" % params, connect_args={'attrs_before': {SQL_COPT_SS_ACCESS_TOKEN:tokenstruct}})
conn=engine.connect()
print(conn)

result = conn.execute("select * from tb1")
for row in result:
    print(str(row[0]) + " " + str(row[1]))
conn.close()

我从门户网站获得连接字符串：

希望这会有所帮助。