Interface og multi inheritance?

PHP kode 

 $Account = new Account(1);
 
 echo $Account->Character->GetFromCharacter('name', 'WHERE ID = 1');
 
 
 <?php
 
 class Account
 {
 private $PlayerID;
 protected $CharacterLink;
 
     function __construct($ID)
     {
         $this->PlayerID = $ID;
         
     }
 
     public function Character()
     { return $this->CharacterLink; }
 
 }
 
 class Character
 {
     function __construct()
     {
         
     }
 
     public function GetFromCharacter($what, $where)
     {
         $db::obtain();
         SQL_FIS...
     }
 }
 
 ?>

PHP kode 

 <?php
 class Account extends AccountList {
     public function __construct($id) {
     
     }
     
     public function getCharacters() {
         $col = new CharacterCollection();
         $result = $col->load(array(
             Character::FIELD_ACCOUNT => $this->get('id')
         ));
         return $result;
     }
     
     public function getCharacters() {
         $col = new CharacterCollection();
         $result = $col->load(array(
             Account::FIELD_CURRENT_CHARACTER => $this->get('current_character')
         ));
         return $result;
     }
 }
 
 class CharacterCollection {
     public function __construct() {
     }
     
     public function load() {
         $result = $this->getDAO()->read(
             // $filter = array(
             //         FIELD_NAME = '%Superman%
             // )
         );
         if($result) {
             foreach($result as $idx => $row) {
                 $result[$idx] = new Character($result[$idx]); 
             }
         }
         return $result;
     }
     
     protected function getDAO() {
         if($this->dao) {
             $this->dao = new DAO_Character();
         }
         return $this->dao;
     }
 }
 
 class Character extends CharacterCollection {
     const FIELD_ID = 'pk_character_id';
     
     public function __construct($data) {
         if(is_array($data)) {
             foreach($data as $key => $value) {
                 $this->set($key, $value);                
             }
         } else {
             $this->set('id', $data);
         }    
     }
     
     public function load($id) {
         $result = $this->getDAO()->read(array(
             self::FIELD_ID => $id
         ));
         
         if($result) {
             $this->props = array_merge($this->props,$result);
         }
     }
     
     public function set($key, $val) {
         $this->props[$key] = $val;
     }
      
     public function get($key) {
         return $this->props[$key];
     } 
 }
 
 // Fetch all characters from one account
 $account = new Account(1);
 $characters = $account->getCharacters();
 
 echo $characters[0]->get('name');
 
 // Fetch a single character from one account
 $account = new Account(2);
 $character = $account->getCurrentCharacter();
 
 echo $character->get('name');