Save button for each row in the table. PHP MYSQL - php

Question

Please help, each row in the table has save button for editing/adding content. I have 3 textboxes in each row,PersoninCharge,PIC_Comments and Status. The user can add/edit these textboxes whenever they click the save button on that particular row. The problem is, whenever I add/edit data in one row, the save button can't read what particular row I edited.
The save button is perfectly running if I searched the invoice number first, but what I want is to directly edit/add the data in each row without searching it first.
Here's the code:
For the table:
<?php
if (mysqli_num_rows($result) > 0)
{
while($row = mysqli_fetch_array($result))
{
echo"<tr class=output2>";
echo "<td>$row[1]</td>";
echo "<td>$row[2]</td>";
echo "<td>$row[3]</td>";
echo "<td>$row[4]</td>";
echo "<td>$row[5]</td>";
echo "<td>$row[6]</td>";
echo "<td>$row[7]</td>";
echo "<td>$row[8]</td>";
echo "<td>$row[9]</td>";
echo "<td>$row[10]</td>";
echo "<td>$row[11]</td>";
echo "<td>$row[12]</td>";
echo "<td><input type='text' name='pic' value='$row[17]'></td>";
echo "<td><input type='text' name='comt' value='$row[18]'></td>";
echo "<td><input type='text' name='stat' value='$row[19]'></td>";
echo "<td><form name='update' method='POST'><input type='submit' name='save_btn' value='SAVE' style='font-size:1em;'/></form></td>";
echo "<td><input type='hidden' name='idtxt' value='$row[0]'/></td>";
echo "</tr>";
}
}
else
{
echo '<h3>No result found! </h3><br>';
}
$con->close();
For Save button:
if(isset($_POST['save_btn']))
{
$query2="UPDATE invalid_invoice SET UpdateBy='".$_SESSION['login_user']."', UpdateDateTime=NOW(), PersoninCharge='".$_POST['pic']."', PIC_Comments='".$_POST['comt']."', Status='".$_POST['stat']."' WHERE ID='".$_POST['idtxt']."'";
$con->query($query2);
$con->close();
echo '<h3 class="datasuccess">Data successfully added!</h3>';
}

Answer 1

I have edited your form. please have a look
<?php
if (mysqli_num_rows($result) > 0)
{
while($row = mysqli_fetch_array($result))
{
echo"<form name='update' method='POST'><tr class=output2>";
echo "<td>$row[1]</td>";
echo "<td>$row[2]</td>";
echo "<td>$row[3]</td>";
echo "<td>$row[4]</td>";
echo "<td>$row[5]</td>";
echo "<td>$row[6]</td>";
echo "<td>$row[7]</td>";
echo "<td>$row[8]</td>";
echo "<td>$row[9]</td>";
echo "<td>$row[10]</td>";
echo "<td>$row[11]</td>";
echo "<td>$row[12]</td>";
echo "<td><input type='text' name='pic' value='$row[17]'></td>";
echo "<td><input type='text' name='comt' value='$row[18]'></td>";
echo "<td><input type='text' name='stat' value='$row[19]'></td>";
echo "<td><input type='submit' name='save_btn' value='SAVE' style='font-size:1em;'/></td>";
echo "<td><input type='hidden' name='idtxt' value='$row[0]'/></td>";
echo "</tr></form>";
}
}
else
{
echo '<h3>No result found! </h3><br>';
}
$con->close();