Getting fetchAll() error using on Ubuntu

Question

I am trying to fetch data from a remote MSSQL Server. I am using WampServer on Windows 7 64bit Professional. My connection string is as follows:

$pdo = new PDO('sqlsrv:Server='.$host.';Database=' . $db, $user, $pass, 
               array(
                     PDO::ATTR_EMULATE_PREPARES => false,
                     PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION
                    )
             );

I can successfully connect from my local computer and execute queries with this connection. Then I have uploaded my source to server which runs on Ubuntu 14.04 TLS. I got 0-no driver-found error. After that I have searched that this connection string is invalid for Ubuntu. I have updated it to

 $pdo = new PDO('odbc:Driver=freetds; Server=1.2.3.4; Port=1433; Database=myDB; UID=myUser; PWD=myPass;');

After a few configuration, I could have succeeded to connect to the database with no error. But after querying then I try to use PDO's fetchAll() method I get the following error:

PHP Fatal error: Call to a member function fetchAll() on a non-object

The code is the same with I always use. I think this is because of connection. But I do not know what to do next?

EDIT:

I can run this script on my local computer with no error. But it does not work on Ubuntu.