Solution : PyMSSql - import _mssql - ImportError: DLL load failed: The specific module could not be found

When you install pymssql module using pip in python and then try to import pymssql, you may end up with “PyMSSql - import _mssql - ImportError: DLL load failed: The specific module could not be found” error, if you are using pymssql version 2.1 or greater.

This is due to security reason, pymssql now is not linked with SSL and FreeTDS, unlike previous version where SSL and FreeTDS were jointly linked with pymssql during installation.

This information can be found on pymssql site found http://pymssql.org/en/latest/freetds.html#windows

In order to overcome, we need to install supporting components FreeTDS and OpenSSL independently and then pymssql will work without any issue.

Below are the steps to download and configure FreeTDS and OpenSSL.

FreeTDS can be downloaded https://github.com/ramiro/freetds/releases

And extract the file which is download. Now place the extract folder where your python module is installed. 

(Can be kept anywhere but to avoid accident deletion of the folder, I prefer here). I had my extracted folder in C:\Program Files\Python 3.5\freetds-v0.95.95-win-x86_64-vs2015

Now you may add the folder lib-nossl in FreeTDS to Environmental Variables in Windows.

(Ex: C:\Program Files\Python 3.5\freetds-v0.95.95-win-x86_64-vs2015\freetds-v0.95.95-win-x86_64-vs2015\lib-nossl)

If an SSL connection is not required, then we just have to download the FreeTDS components and ensure that the contents of the "lib-nossl" folder can be found by searching the Windows PATH.

If an SSL connection is required then we have to download both the FreeTDS and OpenSSL components and ensure that the appropriate DLLs (in the "lib" folder for FreeTDS, and in the "bin" or "bin64" folder for OpenSSL) can be located by searching the Windows PATH.