Zend_Db_Table_Abstract

<?phpclass models extends Zend_Db_Table_Abstract{    protected $_name = 'models';    protected $_primary = 'model_id';    protected $_dependentTables = array('models','inventory');    protected $_referenceMap    = array(        'makes' => array(            'columns'           => 'make_id',            'refTableClass'     => 'makes',            'refColumns'        => 'make_id'        ),    );}class makes extends Zend_Db_Table_Abstract{    protected $_name = 'makes';    protected $_primary = 'make_id';    protected $_dependentTables = array('inventory');}class inventory extends Zend_Db_Table_Abstract{    protected $_name = 'inventory';        protected $_primary = 'inventory_id';        protected $_referenceMap    = array(        'models' => array(            'columns'           => 'model_id',            'refTableClass'     => 'models',            'refColumns'        => 'model_id'        ),        'makes' => array(            'columns'           => 'make_id',            'refTableClass'     => 'makes',            'refColumns'        => 'make_id'        ),    );    protected $_dependentTables = array('models','inventory');}