Mapping object relations - Foreign key associations - Tree structure.php

<?php
class Task extends Doctrine_Record {
     public function setUp() {  
        $this->hasOne("Task as Parent","Task.parent_id");
        $this->hasMany("Task as Subtask","Subtask.parent_id");
    }
    public function setTableDefinition() {
        $this->hasColumn("name","string",100);
        $this->hasColumn("parent_id","integer");
    }
}
?>