class Default_Model_Test {
    private $_conn;
    private $_frontController;

    public function  __construct() {
        $this->_frontController = Zend_Controller_Front::getInstance();
        $this->_conn = $this->_frontController->getParam('bootstrap')->getResource('db');
    }

    public function getAll(){
        $sql = "SELECT * FROM tbl";
        $rowSet = $this->_conn->fetchAll($sql);
    }

    public function incVal($fieldID){
        $sql = "UPDATE tbl SET field=field+1 WHERE id = " . $fieldID;
        // ???
    }
}