pulling database and update database - php - php

Question

I have rows showing products and their stockings.
I can pull out records from the database but somehow I am stuck at the editing part. When I click on edit I don't know how to pass the id so I can use the id to select what is needed to be selected in the table.
I have something like stock.php which shows all item_name and stock
<?php
$sql = "SELECT * FROM inventory";
$result = mysqli_query($mysqli,$sql);
//make sure database queries
if (!$result) {
echo "DB Error, could not query the database\n";
echo 'MySQL Error: ' . mysql_error();
exit;
}
if ($result->num_rows > 0) {
echo "<table><tr><td>Name</td>
<td>Stock</td>
</tr>";
// output data of each row
while($row = $result->fetch_assoc()) {
$id = $row['id'];
echo "<tr>
<td>".$row["item_name"]."</td>
<td>".$row["stock"]."</td>
<td>
<form action='edit.php' method='POST'>
<input type='hidden' name='$id' value='$id'/>
<input type='submit' name='edit' value='edit' />
</form>
</td>
</tr>";
}
echo "</table>";
} else {
echo "0 results";
}
?>
in my edit.php I have something like this which is giving me error because the $id is not passed
include_once "init.php";
if ($_SERVER['REQUEST_METHOD']=='POST') {
// query the table by matching up the int id
$sql = "SELECT * FROM inventory WHERE id = '$id'";
}
I want to pull out the data again in a new page and then having input box again to let users update stock # or even the product name and others if necessary.

Answer 1

There is an error in your input declaration. HTML items can't have names that start with special characters (like the $). You should be setting the variable-based names this way:
<input type='hidden' name='".$id."' value='".$id."'/>
Also in your edit.php, your SQL statement has a bug.
$sql = "SELECT * FROM inventory WHERE id = '$id'";
should be:
$sql = "SELECT * FROM inventory WHERE id = ".intval($id);

Answer 2

You need to do the following updates:
stock.php
<input type='hidden' name='id' value='$id'/>
edit.php
$sql = "SELECT * FROM inventory WHERE id = '".$_POST["id"]."'";
you are passing the current id value as the post var name, the var's name should be "id"