On Linux you can choose between (for the two former choices, when you start the the pymssql installation process it will look for and pick the header files and libraries for FreeTDS in some usual system-wide locations):

  • Use the FreeTDS installation provided by the packages/ports system.

  • Build it and install yourself.

  • Use the bundled static FreeTDS libraries:

    pip install pymssql

    These static libraries are built on a x86_64 Ubuntu 14.04 system by using the following sequence:

    export CFLAGS="-fPIC"  # for the 64 bits version


    export CFLAGS="-m32 -fPIC" LDFLAGS="-m32"  # for the 32 bits version

    and then:

    ./configure --enable-msdblib --enable-sspi \
      --prefix=/usr --sysconfdir=/etc/freetds --with-tdsver=7.1 \
      --disable-apps --disable-server --disable-pool --disable-odbc \
      --with-openssl=no --with-gnutls=no

    Changed in version 2.1.2: Version of FreeTDS Linux static libraries bundled with pymssql is 0.95.81 obtained from branch Branch-0_95 of the official Git repository. Up to 2.1.1 the version of FreeTDS bundled was 0.91.

Mac OS X (with Homebrew)

brew install freetds


  1. You can:

    • Use binaries we maintain at

      Those are built with SSL support via OpenSSL (see below) and iconv (via win-iconv statically linked).

      Choose the .zip file appropriate for your architecture (x86 vs. x86_64) and your Python version (vs2008 for Python 2.7, vs2010 for Python 3.3 and 3.4, vs2015 for Python 3.5). Download and uncompress it taking note of the path to the directory which contains the DLL files.

    • Or you can build it yourself.

  2. If you chose the FreeTDS binaries linked above then you’ll need to install OpenSSL. The binaries you’ll need can be downloaded from

    Choose the right .7z file for your Python version (vs2008 for Python 2.7, vs2010 for Python 3.3 and 3.4, vs2015 for Python 3.5). Download and uncompress it taking note of the path to the directory which contains the DLL files.

    This is needed because the FreeTDS DLLs are compiled with the feature to use SSL-wrapped connections to SQL Server (and Azure for which it’s a mandatory requirement) turned on.

  3. If applicable, add the directories that hold the above DLLs to your PATH environment variable.


FreeTDS is now linked in dynamically on Windows

pymssql version 2.1.2 includes a change in the official Windows binaries: FreeTDS isn’t statically linked as it happened up to release 2.1.1, as that FreeTDS copy lacked SSL support.

Given the fact OpenSSL is a relatively fast-moving target and a sensitive one security-wise, we’ve chosen to not link it statically either so it can be updated independently to future releases which include security fixes.

We are trying to find a balance between security and convenience and will be evaluating the situation for future releases. Your feedback is greatly welcome.


pymssql uses FreeTDS package to connect to SQL Server instances. You have to tell it how to find your database servers. The most basic info is host name, port number, and protocol version to use.

The system-wide FreeTDS configuration file is /etc/freetds.conf or C:\freetds.conf, depending upon your system. It is also possible to use a user specific configuration file, which is $HOME/.freetds.conf on Linux and %APPDATA%\.freetds.conf on Windows. Suggested contents to start with is at least:

    port = 1433
    tds version = 7.0

With this config you will be able to enter just the hostname to pymssql.connect() and _mssql.connect():

import pymssql
connection = pymssql.connect(server='mydbserver', ...)

Otherwise you will have to enter the portname as in:

connection = pymssql.connect(server='mydbserver:1433', ...)

To connect to instance other than the default, you have to know either the instance name or port number on which the instance listens:

connection = pymssql.connect(server='mydbserver\\myinstancename', ...)
# or by port number (suppose you confirmed that this instance is on port 1237)
connection = pymssql.connect(server='mydbserver:1237', ...)

Please see also the pymssql module reference, _mssql module reference, and FAQ pages.

For more information on configuring FreeTDS please go to

Testing the connection

If you’re sure that your server is reachable, but pymssql for some reason don’t let you connect, you can check the connection with tsql utility which is part of FreeTDS package:

$ tsql
Usage:  tsql [-S <server> | -H <hostname> -p <port>] -U <username> [-P <password>] [-I <config file>] [-o <options>] [-t delim] [-r delim] [-D database]
$ tsql -S mydbserver -U user


Use the above form if and only if you specified server alias for mydbserver in freetds.conf. Otherwise use the host/port notation:

$ tsql -H mydbserver -p 1433 -U user

You’ll be prompted for a password and if the connection succeeds, you’ll see the SQL prompt:


You can then enter queries and terminate the session with exit.

If the connection fails, tsql utility will display appropriate message.