Oracle数据库使用fetch更改行值

Question

我的数据库中的行没有改变，即使它能够从该行调用而不是写入它

<?php
    $formId = $_POST["formId"];
    $newSuper = $_POST["newSuper"];
    $return = $_POST;

    require_once('mcl_Oci.php');
    $xdm = new mcl_Oci("xdm");

    $sql = "SELECT x.*,x.ROWID FROM INTOXDM.ASTP_FORM x WHERE x.FORMID = '".$formId."'";

    while($row = $xdm->fetch($sql)){

        $row['SUPERVISOR_EID'] = $newSuper; 

    }

    $return["json"] = json_encode($return);
    echo json_encode($return);
?>