Группировка массива

$db = array(
 array ("id" => "02003", "name" => "A", "attr" => "white"),
 array ("id" => "02004", "name" => "B", "attr" => "black"),
 array ("id" => "02005", "name" => "C", "attr" => "yellow"),
 array ("id" => "group", "name" => "D", "attr" => "02006, 02007, 02008"),
 array ("id" => "02006", "name" => "E", "attr" => "gray"),
 array ("id" => "02007", "name" => "F", "attr" => "red"),
 array ("id" => "02008", "name" => "G", "attr" => "green")
);

$db = array(
 array ("id" => "02003", "name" => "A", "attr" => "white"),
 array ("id" => "02004", "name" => "B", "attr" => "black"),
 array ("id" => "02005", "name" => "C", "attr" => "yellow"),
 array (
  array("id" => "group", "name" => "D", "attr" => "02006, 02007, 02008"),
  array ("id" => "02006", "name" => "E", "attr" => "gray"),
  array ("id" => "02007", "name" => "F", "attr" => "red"),
  array ("id" => "02008", "name" => "G", "attr" => "green")
 )
);

foreach ($db as $item){
    if ($item['id']=='group'){
 
        $group[] = $item;
 
        unset($db[индекс текущего массива]);
        $add_items = explode(",", str_replace(" ","",$item['attr']));
        
        foreach ($add_items as $find_row){
            поиск в $db значения $find_row
            определить какой это индекс первичного массива
            $group[] = $db[индекс];
            unset($db[индекс]);
        }
        $db[] = $group;
 
    }
}

foreach ($db as $item){
    if ($item['id']=='group'){
 
        $group[] = $item;
        unset($db[array_search($item, $db)]);
 
        $add_items = explode(",", str_replace(" ","",$item['attr']));
        foreach ($add_items as $find_row){
            foreach ($db as $key) {
                if ($key['id'] == "$find_row"){
                    $group[] = $key;
                    unset($db[array_search($key, $db)]);
                }
            }
        }
        $db[] = $group;
 
    }
}

if ($key['id'] == $find_row)

foreach ($db as $a => $item){
    if ($item['id']=='group'){
        $group[] = $item;
        unset($db[$a]);