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DOMAIN\user SQL Server login works with pyodbc/FreeTDS but fails with mssql_python #625
Description
I am using mssql_python against an on-prem SQL Server using a domain-style username DOMAIN\username but with a password.
The same server, database, username and password work when using pyodbc with the FreeTDS ODBC driver, but fail with mssql_python. The error message is
mssql_python.exceptions.OperationalError: Driver Error: Invalid authorization specification; DDBC Error: [Microsoft][SQL Server]Login failed for user 'DOMAIN\username'.
To reproduce
This code below works:
import pyodbc
s=r"DRIVER=FreeTDS;SERVER=servername;PORT=1433;DATABASE=DM_Database;UID=DOMAIN\username;PWD=J...;TDS_Version=7.4;Encrypt=yes"
conn = pyodbc.connect(_s)
This code below fails with the message reported above:
import mysql_python
s = r"SERVER=servername,1433;Database=DM_Database;UID=DOMAIN\username;PWD=J...;Encrypt=yes;
conn = mssql_python.connect(s)
Further technical details
Python version: 3.10.12
mssql_python: 1.8.0
SQL Server version: SQL Server 2022 (Must be verified, but this is what my documentation says)
Operating system: Ubuntu 22.04.5 LTS
Activity
github-actions commentedon Jun 4, 2026
Hi Tage-Politi, thank you for opening this issue!
Our team will review it shortly. We aim to triage all new issues within 24-48 hours and get back to you.
If you have additional information to share, please feel free to update the issue.
Thank you for your patience!
Tage-Politi commentedon Jun 4, 2026
Database confirmeed to be:
sumitmsft commentedon Jul 6, 2026
Hi Tage-Politi Thanks for the report. Since you’re running on Ubuntu 22.04, we want to clarify the authentication mode here.
Since your working comparison uses pyodbc with FreeTDS, this may reflect a driver-specific behavior difference rather than a bug in mssql_python.
Can you confirm whether DOMAIN\username is a SQL login whose literal name includes a backslash?
If it’s the latter, we can investigate further as a compatibility issue.
Tage-Politi commentedon Jul 7, 2026
For mundane reasons and this particular use-case, the username unfortunately is indeed the name of a domain, a
\, and then a "classic" username.The
pyodbc-driver seems to pass the username through.