Sie können foreach loop through while verwenden als:Co-supervisor :
<?php
echo '<select name="cosupervisor">';
while($row3 = oci_fetch_array($sql3,OCI_ASSOC+OCI_RETURN_NULLS))
{
$data[] = $row3 ;
}
foreach($data as $value)
{
echo '<option value="'.$value['STFNAME'].'">'.$value['STFNAME'].'</option>'; }
echo '</select>'; ?>
</td>
?>
</td>