SQLSRV 3.2 is now available from Microsoft that supports PHP 5.6
http://www.microsoft.com/en-us/download/details.aspx?id=20098
PDO_SQLSRV is a driver that implements the PHP Data Objects (PDO) interface to enable access from PHP to MS SQL Server (starting with SQL Server 2005) and SQL Azure databases.
The most recent version of the driver is available for download here: » SQLSRV download. The driver sources are hosted in a » public repository.
For more information about system requirements, see » SQLSRV System Requirements.
On Windows the PDO_SQLSRV extension is enabled by downloading and adding appropriate DLL files to the PHP extension directory and the corresponding entry to the php.ini file.
On Linux and macOS, the PDO_SQLSRV extension can be installed using » PECL. See the » installation tutorial for details.
The constants below are defined by
this driver, and will only be available when the extension has been either
compiled into PHP or dynamically loaded at runtime. In addition, these
driver-specific constants should only be used if you are using this driver.
Using driver-specific attributes with another driver may result in
unexpected behaviour. PDO::getAttribute() may be used to
obtain the PDO::ATTR_DRIVER_NAME
attribute to check the
driver, if your code can run against multiple drivers.
PDO::SQLSRV_TXN_READ_UNCOMMITTED
(int)
PDO::SQLSRV_TXN_READ_COMMITTED
(int)
PDO::SQLSRV_TXN_REPEATABLE_READ
(int)
PDO::SQLSRV_TXN_SNAPSHOT
(int)
PDO::SQLSRV_TXN_SERIALIZABLE
(int)
PDO::SQLSRV_ENCODING_BINARY
(int)
PDO::SQLSRV_ENCODING_SYSTEM
(int)
PDO::SQLSRV_ENCODING_UTF8
(int)
PDO::SQLSRV_ENCODING_DEFAULT
(int)
PDO::SQLSRV_ATTR_QUERY_TIMEOUT
(int)
PDO::SQLSRV_ATTR_DIRECT_QUERY
(int)
SQLSRV 3.2 is now available from Microsoft that supports PHP 5.6
http://www.microsoft.com/en-us/download/details.aspx?id=20098
An updated driver compatible with both PHP 7.0 and Linux is available on the PHP-7.0-Linux branch of https://github.com/Microsoft/msphpsql/
This is more up to date and supports some additional features over the ODBC / DBLIB drivers.
It is currently considered an 'Early Technical Preview' and hence has some limitations, but in my experience it has been stable.
As of 12/12/2014, Microsoft has officially released Version 3.1.
Support for 5.5 has 4 drivers
php_pdo_sqlsrv_55_nts.dll
php_pdo_sqlsrv_55_ts.dll
php_sqlsrv_55_nts.dll
php_sqlsrv_55_ts.dll
Note: Version 3.1 now supports PHP 5.5 and requires Microsoft ODBC Driver 11 (or higher)
You can downlod the new driver from
http://www.microsoft.com/en-us/download/details.aspx?id=20098
Watch out!
If you use PDO SQLSRV on windows 7, using 32 bit php on XAMMP, you might encounter driver problems : "This extension requires the Microsoft ODBC Driver 11 for SQL Server to communicate with SQL Server"
The reason, Microsoft 32-bit ODBC driver doesn't install properly on 64-bit Windows 7.
Check the solution to PDO SQLSRV driver problem here in StackOverflow
https://stackoverflow.com/a/46245990/1330248