Acceso a SqlServer desde zend

[asanzred]

Buenas, estoy empezando a desarrollar un portal en zend que conecta de dos bases de datos distintas: Una mysql (la principal) y una SqlServer (secundaria).

Antes de exponer mi error decir que la conexión a ambas bases de datos es correcta y soy capaz de ejecutar consultas en ambas con resultados positivos.

Mi problema empieza al crear el siguiente modelo de datos:

Código PHP:

class Application_Model_DbTable_Contact extends Zend_Db_Table_Abstract
{
 
    protected $_name = 'Contact';
    protected $_dbadapter = null;
    
    public function init()
    {
        //load the other adapter
        $registry=Zend_Registry::getInstance();
        $session = $registry['session'];
        $this->_dbadapter = $session->dbNav;
    }
    
    function fetchAll($where = null, $order = null, $count = null, $offset = null) {
//        print_object($this->_dbadapter);
        
        $this->_dbadapter->fetchAll();
    }
 

Código PHP:

class Application_Model_Contact
{
public function __set($name, $value)
    {
        $method = 'set' . $name;
        if (('mapper' == $name) || !method_exists($this, $method)) {
            throw new Exception('Invalid user property');
        }
        $this->$method($value);
    }
    
    public function __get($name)
    {
        $method = 'get' . $name;
        if (('mapper' == $name) || !method_exists($this, $method)) {
            throw new Exception('Invalid user property');
        }
        return $this->$method();
    }
 public function getNo_() {
        return $this->_No_;
    }
 
    public function setNo_($No_) {
        $this->_No_ = (string) $No_;
        return $this;
    }
}
 

Código PHP:

class Application_Model_ContactMapper
{
    protected $_dbTable;
 
    public function setDbTable($dbTable)
    {
        if (is_string($dbTable)) {
            $dbTable = new $dbTable();
        }
        if (!$dbTable instanceof Zend_Db_Table_Abstract) {
            throw new Exception('Invalid table data gateway provided');
        }
        $this->_dbTable = $dbTable;
        return $this;
    }
 
    public function getDbTable()
    {
        if (null === $this->_dbTable) {
            $this->setDbTable('Application_Model_DbTable_Contact');
        }
        return $this->_dbTable;
    }
   // .....
public function fetchAll()
    {
        $resultSet = $this->getDbTable()->fetchAll();
 
            $entries   = array();
            foreach ($resultSet as $row) {
            $entry = new Application_Model_Contact();
            $entry->setName($row->Name);
            $entries[] = $entry;
        }
        return $entries;
    }
}
 

Y el error es el siguiente:

Exception information:

Message: [Microsoft][Administrador de controladores ODBC] Longitud de cadena o de b�fer no v�lida
Stack trace:

#0 C:\xampp\htdocs\Portal\library\Zend\Db\Statement.p hp(115): Zend_Db_Statement_Sqlsrv->_prepare(NULL)
#1 C:\xampp\htdocs\Portal\library\Zend\Db\Adapter\Sql srv.php(298): Zend_Db_Statement->__construct(Object(Zend_Db_Adapter_Sqlsrv), NULL)
#2 C:\xampp\htdocs\Portal\library\Zend\Db\Adapter\Abs tract.php(478): Zend_Db_Adapter_Sqlsrv->prepare(NULL)
#3 C:\xampp\htdocs\Portal\library\Zend\Db\Adapter\Abs tract.php(736): Zend_Db_Adapter_Abstract->query(NULL, Array)
#4 C:\xampp\htdocs\Portal\application\models\DbTable\ Contact.php(20): Zend_Db_Adapter_Abstract->fetchAll()
#5 C:\xampp\htdocs\Portal\application\models\ContactM apper.php(61): Application_Model_DbTable_Contact->fetchAll()
#6 C:\xampp\htdocs\Portal\application\controllers\Use rsController.php(55): Application_Model_ContactMapper->fetchAll()
#7 C:\xampp\htdocs\Portal\library\Zend\Controller\Act ion.php(516): UsersController->userpageAction()
#8 C:\xampp\htdocs\Portal\library\Zend\Controller\Dis patcher\Standard.php(295): Zend_Controller_Action->dispatch('userpageAction')
#9 C:\xampp\htdocs\Portal\library\Zend\Controller\Fro nt.php(954): Zend_Controller_Dispatcher_Standard->dispatch(Object(Zend_Controller_Request_Http), Object(Zend_Controller_Response_Http))
#10 C:\xampp\htdocs\Portal\library\Zend\Application\Bo otstrap\Bootstrap.php(97): Zend_Controller_Front->dispatch()
#11 C:\xampp\htdocs\Portal\application\Bootstrap.php(8 0): Zend_Application_Bootstrap_Bootstrap->run()
#12 C:\xampp\htdocs\Portal\library\Zend\Application.ph p(366): Bootstrap->run()
#13 C:\xampp\htdocs\Portal\public\index.php(27): Zend_Application->run()
#14 {main}


Si podeis ayudarme os lo agradeceria, no tengo claro ni porque da el error, la llamada la hago asi:

Código PHP:

$contacts = new Application_Model_ContactMapper();
        $this->view->contacts = $contacts->fetchAll();
 

como en los ejemplos de Zend oficiales