How to use multiple forms to submit unique data PHP/MySQL - php

Question

The way I've structured my form data is by creating them in a while loop, but each time they are created the form will take a unique id.
So my question is, how do I access them individually and update specified data to a MYSQL server.
I've attempted to do it in the code at the end of the script, but I'm not sure how to access the forms individually
<?php
include 'user_data.php';
include 'core.inc.php';
$query = mysql_query("SELECT `post_text` FROM `posts`,`sub_posts` WHERE sub_posts.post_id = posts.id AND sub_posts.user_id='$user_id'");
while($row = mysql_fetch_array($query)){
?><?php echo $row[post_text].'<br>'?>
<form action="<?php $curent_file ?>" method="POST">
<textarea name="answer_field" > </textarea><br />
<input type="submit" value="Submit Answer">
<input type="hidden" name="post_id" value="<?php echo $row['post_id']; ?>" />
</form>
<?php
}//While Loop
if (isset($_POST['answer_field']) && !empty($_POST['answer_field'])){
$answer = mysql_real_escape_string($_POST['answer_field']);
$id = intval($_POST ['post_id']);
$query = "UPDATE `sub_posts` SET `sub_answer`='$answer' WHERE `post_id`='$id'";
}
?>

Answer 1

Only a single form gets posted when clicking the "submit" field. The form name does not get submitted by itself. Instead, you would place the post ID to which the form corresponds as a hidden field:
<input type="hidden" name="post_id" value="<?php echo $row['post_id']; ?>" />
And then later:
$answer = mysql_real_escape_string ($_POST ['answer']);
$id = intval ($_POST ['post_id']);
$query = "UPDATE `sub_posts` SET `sub_answer`='{$answer}' WHERE `post_id`={$id}";
Note that you definitely need to escape the answer before putting it in the query and make sure that the ID is a number. Otherwise, you're opening up your code to SQL injection attacks.