<?php
// sample code to illustrate the use of factory design pattern 
// Each class and the actual implementation logic can be in separate files.
// http://royads.blogspot.com
class mysqlClass
{
  function __construct($config = array())
  { 
    echo 'connecting to mysql server ..';
    
  }
}

class mssqlClass
{
  function __construct($config = array())
  { 
    echo 'connecting to mssql server ..';
  }
}


class Database
{
   // This is a factory method because it allows us to instantiate other class
   public static function dbFactory($db,$config = array())
    {
       switch($db)
        {
	 case "mysql" :
	              // load the required class if its in another php file
		      // create the object of selected database class
		      $dbObject = new mysqlClass();
	              break;
	 case "mssql" :
	              // load the required class if its in another php file
		      // create the object of selected database class
		      $dbObject = new mssqlClass();
	              break;
	}

	return $dbObject;
    }
}

$db = Database::dbFactory('mysql',array('host','username','pass','dbname'));

echo "\n";

$db = Database::dbFactory('mssql',array('host','username','pass','dbname'));

?>

connecting to mysql server ..
connecting to mssql server ..