Microsoft has developed their official driver for connecting to MS SQL 2008+ server databases with PHP 7.2 and above. The driver requires PHP 7.2 (their current latest version 5.8.0) and the Microsoft ODBC Driver. It would be good to have this driver available in the tree. Thank you!
I've tried this like a year ago, the php part is trivial, but the odbc driver just didn't work for me. No matter which openssl library was installed, it crashed with some openssl error. So good luck :)