Should I be extending this class? (PHP)

// Customer.class.php
function getByName($name) {
    // SELECT * FROM `customer` WHERE `name` = $name
}

// ** this could instead be written as: **
// ORM.class.php
function getByField($field, $value) {
    // SELECT * FROM `$this->table` WHERE `$field` = $value
}

// Customer.class.php
function getByName($name) {
    // SELECT * FROM `customer` WHERE `name` = $name
}

// ** this could instead be written as: **
// ORM.class.php
function getByField($field, $value) {
    // SELECT * FROM `$this->table` WHERE `$field` = $value
}

class Customer {
    public $name;
    public function save() {
        $orm = new ORM('customers', 'id'); // table name and primary key
        $orm->name = $this->name;
        $orm->save();
    }
}

class Poll extends dbObject // dbObject is my ORM. Poll can extend it so it gets all properties.
{
    	function __construct($ID=false)
    	{
    		$this->__setupDatabase('polls', // db table
    			array('ID_Poll' => 'ID',	// db field => object property
    					'strPollQuestion' => 'strpollquestion',
    					'datPublished' => 'datpublished',
    					'datCloseDate' => 'datclosedate',
    					'enmClosed' => 'enmclosed',
    					'enmGoedgekeurd' => 'enmgoedgekeurd'),
    					'ID_Poll',	// primary db key
    					$ID);	// primary key value
		$this->addRelation('Pollitem'); //Connect PollItem to Poll 1;1
		$this->addRelation('Pollvote', 'PollUser'); // connect pollVote via PollUser (many:many)


    	}

function Display()
{

 // do your displayíng for poll here:
    $pollItems = $this->Find("PollItem"); // find all poll items
    $alreadyvoted = $this->Find("PollVote", array("IP"=>$_SERVER['REMOTE_ADDR'])); // find all votes for current ip
}