The SQLSRV driver is a Microsoft supported PHP extension that allows you to access Microsoft SQL Server and SQL Azure databases. It is an alternative for the MSSQL drivers that were deprecated as of PHP 5.3, and have been removed from PHP 7.
The SQLSRV extension can be used on the following operating systems:
The SQLSRV extension requires that the Microsoft SQL Server 2012 Native Client be installed on the same computer that is running PHP. If the Microsoft SQL Server 2012 Native Client is not already installed, click the appropriate link at the "Requirements" documentation page.
To download the latest SQLSRV drivers, go to the following: Download
A full list of system requirements for the SQLSRV Drivers can be found here: System Requirements
Those using SQLSRV 3.1+ must download the Microsoft ODBC Driver 11 for SQL Server
PHP7 users can download the latest drivers from GitHub
Microsoft® ODBC Driver 13 for SQL Server supports Microsoft SQL Server 2008, SQL Server 2008 R2, SQL Server 2012, SQL Server 2014, SQL Server 2016 (Preview), Analytics Platform System, Azure SQL Database and Azure SQL Data Warehouse.