嘗試運(yùn)行以下功能時(shí)，出現(xiàn)錯(cuò)誤“ SQLSTATE [HY093]：無(wú)效的參數(shù)號(hào)”：function add_persist($db, $user_id) {    $hash = md5("per11".$user_id."sist11".time());    $future = time()+(60*60*24*14);    $sql = "INSERT INTO persist (user_id, hash, expire) VALUES (:user_id, :hash, :expire) ON DUPLICATE KEY UPDATE hash=:hash";    $stm = $db->prepare($sql);    $stm->execute(array(":user_id" => $user_id, ":hash" => $hash, ":expire" => $future));    return $hash;}我覺(jué)得這很簡(jiǎn)單，我只是沒(méi)有抓住。有任何想法嗎？