value用逗号分割么?$result = array();
while($row = mysql_fetch_array($xxx))
$result[$row['id']] .= isset($result[$row['id']]) ? $row['xyz'] : ','.$row['xyz'];
while($row = mysql_fetch_array($xxx))
$result[$row['id']] .= isset($result[$row['id']]) ? $row['xyz'] : ','.$row['xyz'];
$res[$row["id"]] = $row["value"];
}print_r($res);