<?phpheader("Content-Type: text/html;charset=utf-8");class mssql{    private $host;    private $username;    private $password;    private $database;    private $handle;    private function __construct (Array $config){        $this -> host = $config[‘host‘];        $this -> username = $config[‘username‘];        $this -> password = $config[‘password‘];        $this -> database = $config[‘database‘];        $this -> init();    }    private function init() {        $dsn = ‘sqlsrv:server = ‘.$this -> host.‘;database = ‘.$this->database;        $this -> handle = new PDO($dsn,$this -> username, $this -> password);    }    public static function GetInstance(array $config = null) {        if (null == $config) {            return NULL;        }         static $db = null;        if (null == $db) {            $c = __CLASS__;            $db = new $c($config);        };        return $db -> handle;    }}$config = array(    ‘host‘ => ‘192.168.0.152,1433‘,    ‘database‘ => ‘TimeTracker‘,    ‘username‘ => ‘sa‘,    ‘password‘ => ‘123‘);$mssql = mssql::GetInstance($config);$result = $mssql->query(‘SELECT * FROM T_Sys_UserInfo‘);foreach($result as  $row){    echo $row[2];}?>