class grade_model extends DataMapper { var $model = 'grade_model'; var $table = 'grade'; function __construct($id = NULL) { parent::__construct($id); } } class school_model extends DataMapper { var $model = 'school_model'; var $table = 'school'; var $has_one = array('grade_model'); function __construct($id = NULL) { parent::__construct($id); } }