Follow the same steps to install and enable the PDO drivers of your choice.
Windows users can download the extension DLL php_pdo.dll as part of the PECL collection binaries from http://www.php.net/downloads.php or a more recent version from a PHP 5 PECL Snapshot.
To enable the PDO extension on Windows operating systems, you must add the following line to php.ini: extension=php_pdo.dll
Next, choose the other DB specific DLL files and either use dl() to load them at runtime, or enable them in php.ini below pdo_pdo.dll. For example: extension=php_pdo.dll
extension=php_pdo_firebird.dll
extension=php_pdo_mssql.dll
extension=php_pdo_mysql.dll
extension=php_pdo_oci.dll
extension=php_pdo_oci8.dll
extension=php_pdo_odbc.dll
extension=php_pdo_pgsql.dll
extension=php_pdo_sqlite.dll
These DLL's should exist in the systems extension_dir.
Linux and UNIX
Due to a bug in the pear installer you should install the PDO package manually using the following steps:
Follow the same steps to install and enable the PDO drivers of your choice.
Download the PDO package to your local machine: bash$ wget http://pecl.php.net/get/PDO
Determine your PHP bin directory. If your PHP 5 CLI binary lives at /usr/local/php5/bin/php then the bin dir is /usr/local/php5/bin.
Set your path so that your PHP bin directory is at the front: export PATH="/usr/local/php5/bin:$PATH"
Manually build and install the PDO extension: bash$ tar xzf PDO-0.2.tgz
bash$ cd PDO-0.2
bash$ phpize
bash$ ./configure
bash$ make
bash$ sudo -s
bash# make install
bash# echo extension=pdo.so >> /usr/local/php5/lib/php.ini