使用带有回声的提交按钮更新数据库数据

Question

我想用新数据更新数据库，以便当我单击“提交”按钮时，数据必须存储到数据库中。我这样写，但它不起作用

<?php
$sql=mysqli_query($con,"select doctors.doctorName as docname,appointment.patientName as pname,appointment.*  from appointment join doctors on doctors.id=appointment.doctorId order by appointment.appId desc ");
$cnt=1;
while($row=mysqli_fetch_array($sql))
    {
?>
        <tr>
            <td class="center"><?php echo $cnt;?>.</td>
            <td class="hidden-xs"><?php echo $row['docname'];?></td>
            <td class="hidden-xs"><?php echo $row['appNumber'];?></td>
            <td class="hidden-xs"><?php echo $row['pname'];?></td>
            <td><?php echo $row['doctorSpecialization'];?></td>
            <td><?php echo $row['consultancyFees'];?></td>
            <td><?php echo $row['appointmentDate'];?> / <?php echo
             $row['appointmentTime'];?>
            </td>
            <td><?php echo $row['postingDate'];?></td>
            <td>

            <?php 
                if(($row['currentStatus']==1) && ($row['payment']=='notPaid'))  
                {
                    echo "<b>Active<b> <input type='button' value='Not Paid' style='border-radius: 5px;border: 2px solid  #f44336;color: black;padding: 6px;'>" ;
                }
                if(($row['currentStatus']==1) && ($row['payment']=='paid'))
                {
                    echo "<b>Active<b><br>" ;
                    echo "<input type='submit' value='Paid' style='border-radius: 5px;border: 2px solid  #4CAF50;color: black;padding: 6px;'>" ;
                }
            ?>

            </td>
            <td>
                <div class="visible-md visible-lg hidden-sm hidden-xs">
                    <?php 
                        $appId = $row['appId'];
                        if(($row['currentStatus']==1) && ($row['payment']=='notPaid'))  
                        {
                            echo "Cancel";
                            echo "<button type='submit' name='pay' value='Pay' style='border-radius: 5px;border: 2px solid  #4CAF50;color: black;padding: 12px;'>Pay</button>" ;

                            if (isset($_POST['pay'])) 
                                {
                                    $updatesql = mysqli_query($con,"UPDATE appointment SET payment='paid' WHERE appId='{$appId}'");
                                    if($updatesql)
                                    {
                                        echo "<script>alert('Appoinment has been Paid by Patient');</script>";
                                        echo '<script type="text/javascript">window.location = "appointment-history.php"</script>';
                                    }

                                }
                        }
                        if(($row['currentStatus']==1) && ($row['payment']=='paid'))  
                        {
                            echo "Cancel";
                        }
                    ?>
                </div>
            </td>
        </tr>

<?php 
    $cnt=$cnt+1;
    }

?>

如果我按“付款”按钮，它什么也不会改变。实际上该按钮不起作用。我已经尝试了几件事，但是找不到。我怎样才能解决这个问题？谢谢您的帮助