gistfile1.php

<?php
class Movie extends AppModel {
    // ...
    var $hasMany = array(
        'Poster' => array(
            'className' => 'Media.Attachment',
            'foreignKey' => 'foreign_key',
            'conditions' => array('Poster.model' => 'Movie', 'Poster.group' => 'poster'),
            'dependent' => true,
        ),
        'Photo' => array(
            'className' => 'Media.Attachment',
            'foreignKey' => 'foreign_key',
            'conditions' => array('Photo.model' => 'Movie', 'Photo.group' => 'photo'),
            'dependent' => true,
        ),
        'Trailer' => array(
            'className' => 'Media.Attachment',
            'foreignKey' => 'foreign_key',
            'conditions' => array('Trailer.model' => 'Movie', 'Trailer.group' => 'trailer'),
            'dependent' => true,
        )); 
    // ...
}
?>