UPDATE inside a WHILE statement - php

Question

So, I have a page with a bunch of workorders on it. Each workorder is a row in a single table, and gets put on the page with a while() statement.
I'm trying to update each row with a simple form that I put inside the while(), and an UPDATE/WHERE statement to actually add the information to the table.
Instead of adding it to the specific row, it adds it to Every row. The only thing I can think of is that my WHERE condition is wrong, but I can't seem to figure it out. Maybe it just needs fresh eyes, or maybe I'm heading in Completely the wrong direction.
Also, any specific instructions on security, a better way to do it, etc. would be very helpful. I'm learning PHP on the fly and could use a helping hand. :)
<?php
$query = "SELECT * FROM client_information";
$result = mysql_query($query) or die(mysql_error());
while($row = mysql_fetch_array($result)){
$which_ad = $row['ID'];?>
<b>Name:</b> <? echo $row['billing_name']; ?> <br>
<b>Job Type:</b> <? echo $row['job_type']; ?> <br>
<b>Size:</b> <? echo $row['size']; ?> <br>
<b>Text:</b> <? echo $row['text']; ?> <br>
<b>Notes:</b> <? echo $notes; ?> <br>
<br><br>
<form action="small_update.php" method="POST">
<strong>Email Message:</strong><br>
<textarea rows="8" cols="60" name="email_message"></textarea>
<input type="submit" name="submit" value="Submit"></form>
<?
$email_message = htmlspecialchars ("{$_POST['email_message']}", ENT_QUOTES);
if (mysql_errno() != 0) {
die(mysql_error());
}
mysql_query(
"UPDATE client_information
SET email_message='$email_message'
WHERE ID='$which_ad'"
);
if (mysql_errno() != 0) {
die(mysql_error());
}
}
?>

Answer 1

You don't specify the id in your form:
<form action="small_update.php" method="POST">
<strong>Email Message:</strong><br>
<textarea rows="8" cols="60" name="email_message"></textarea>
<input type="hidden" name="id" value="<?php echo $which_ad; ?>">
<input type="submit" name="submit" value="Submit">
</form>
you need to also make sure you know what id was submitted:
"UPDATE client_information
SET email_message='$email_message'
WHERE ID='$_POST['id']'"
Of course, you're wide open to attacks like this as everyone else is saying. You need to look into mysqli or pdo to sanitize your input...
Ans also upon inspection you're evaluating your post data in the loop. Don't do that. Just do your evaluation before everything else is processed on the page...
<?php
if($_POST)
{
//run processing here
}
// do your fetch code here and display the forms...