doctrine2/models/BoardWithPosition.php

<?php
class BoardWithPosition extends Doctrine_Record {
    public function setTableDefinition() {
        $this->hasColumn('position', 'integer');
        $this->hasColumn('category_id', 'integer');
    }
    public function setUp() {
        $this->hasOne('CategoryWithPosition as Category', array('local' => 'category_id', 'foreign' => 'id', 'onDelete' => 'CASCADE'));
    }
}