Pass variables from a while to another while - php

Question

I have a little problem with this form.
On the fprm page my code is:
<form action="?act=process" method="post">
<?php $sql = "SELECT * FROM schedule WHERE day = '$day' ORDER BY ID ASC";
$hours = mysql_query($sql);
while ($hour = mysql_fetch_array($hours)) { ?>
<input type="text" name="course" value="<?=$hour[course]?>">
<input type="hidden" name="id" value="<?=$hour[ID]?>">
<?php } ?>
<button type="submit">Submit</button>
On the process page looks like this:
while($id = each($_POST['id']) && $course = each($_POST['course']))
{
//echo "ID $id AND course $course<br/>";
}
All I need to do is to pass all variables in a while to update each of them in my sql database.
The error I get is: Warning: Variable passed to each() is not an array or object in /path_domain
How can I fix this?

Answer 1

The reason is you try to use id/course data as array, but you pass just strings. In order to avoid it, just make you form fields as arrays by adding [] to the fields names:
<input type="text" name="course[]" value="<?=$hour[course]?>">
<input type="hidden" name="id[]" value="<?=$hour[ID]?>">

Answer 2

By adding the [] brackets after the name of the fields.
<form action="?act=process" method="post">
<?php $sql = "SELECT * FROM schedule WHERE day = '$day' ORDER BY ID ASC";
$hours = mysql_query($sql);
while ($hour = mysql_fetch_array($hours)) { ?>
<input type="text" name="course[]" value="<?=$hour[course]?>">
<input type="hidden" name="id[]" value="<?=$hour[ID]?>">
<?php } ?>
<button type="submit">Submit</button>