Form values not posting - php

Question

I have two pages. The first one I am sending data over to the second page. The second page I am using to edit the data sent over and other data within my database. I call for the data I sent over like this:
$id = $_POST['id'];
$first = $_POST['first'];
$last = $_POST['last'];
$product = $_POST['product'];
The issue is I have other data on the page that and whenever I edit any of this information, I want to be able to do an UPDATE query to save the new information. However, my query isn't working and I believe it is because my new input field's (data I didn't send over from the first page) data is not being recognized.
Whenever I var_dump the values, I get the data (and in the same format) as how I sent it over to this page.
Here is my code for the second page:
<?php
ini_set('display_errors', 1);
error_reporting(E_ALL);
$id = $_POST['id'];
$first = $_POST['first'];
$last = $_POST['last'];
$product = $_POST['product'];
$newId = filter_var($id, FILTER_SANITIZE_STRING);
try {
$host = 'localhost';
$name = '';
$user = '';
$password = '';
$dbc = new PDO("mysql:host=$host;dbname=$name", $user, $password);
}catch(PDOException $e) {
echo $e->getMessage();
}
$stmt = $dbc->query("SELECT * FROM users WHERE id='$newId' ");
$stmt->setFetchMode(PDO::FETCH_ASSOC);
//print_r($stmt);
while($row = $stmt->fetch()) {
$productAmount = $row['amount'];
$productAvailable = $row['available'];
?>
<form name="update" method="POST">
<input type="text" name="id" value="<?php echo $newId; ?>">
<input type="text" name="first" value="<?php echo $first; ?>">
<input type="text" name="last" value="<?php echo $last; ?>">
<input type="text" name="product" value="<?php echo $product; ?>">
<input type="text" name="amount" value="<?php echo $row['amount']; ?>">
<input type="text" name="available" value="<?php echo $row['available']; ?>">
<button type="submit">Update Product Information</button>
</form>
<?php
}
var_dump($_POST);
if(isset($_POST['update'])) {
$stmt = $dbc->prepare("UPDATE users SET first = ?, last = ?, product = ?, amount = ?, available = ? WHERE id = ?");
$stmt->bindParam(1, $_POST['first']);
$stmt->bindParam(2, $_POST['last']);
$stmt->bindParam(3, $_POST['product']);
$stmt->bindParam(4, $productAmount);
$stmt->bindParam(5, $productAvailable);
$stmt->bindParam(6, $newId);
$stmt->execute();
}
?>
When I do var_dump($_POST); I get the following values, clearly not including the amount and available data.
array(5) { ["id"]=> string(1) "4" ["first"]=> string(3) "Tom" ["last"]=> string(5) "Brady" ["product"]=> string(3) "Tea" ["edit"]=> string(4) "Edit" }
Why isn't all my data being recognized?

Answer 1

Nowhere in your script do you have:
$productAmount = $_POST['amount'];
$productAvailable = $_POST['available'];
Add those 2 lines just below: $product = $_POST['product'];
UPDATED
Is the form supposed to be populated by the database? Or the form itself? If by the database (initially), then you'll need to change all the $variables in the form to their corresponding field names from the table, ie. $row['id'], $row['first'], etc.
See below for update...
<?php
ini_set('display_errors', 1);
error_reporting(E_ALL);
$id = $_POST['id'];
$first = $_POST['first'];
$last = $_POST['last'];
$product = $_POST['product'];
$productAmount = $_POST['amount'];
$productAvailable = $_POST['available'];
$newId = filter_var($id, FILTER_SANITIZE_STRING);
try {
$host = 'localhost';
$name = '';
$user = '';
$password = '';
$dbc = new PDO("mysql:host=$host;dbname=$name", $user, $password);
} catch(PDOException $e) {
echo $e->getMessage();
}
if (isset($_POST['update'])) {
$stmt = $dbc->prepare("UPDATE users SET first = ?, last = ?, product = ?, amount = ?, available = ? WHERE id = ?");
$stmt->bindParam(1, $_POST['first']);
$stmt->bindParam(2, $_POST['last']);
$stmt->bindParam(3, $_POST['product']);
$stmt->bindParam(4, $_POST['amount']);
$stmt->bindParam(5, $_POST['available']);
$stmt->bindParam(6, $newId);
$stmt->execute();
}
if ( !empty($newId) ) {
$stmt = $dbc->query("SELECT * FROM users WHERE id='$newId' ");
$stmt->setFetchMode(PDO::FETCH_ASSOC);
while( $row = $stmt->fetch() ) {
?>
<form action="" method="post">
<input type="text" name="id" value="<?php echo $row['id']; ?>">
<input type="text" name="first" value="<?php echo $row['first']; ?>">
<input type="text" name="last" value="<?php echo $row['last']; ?>">
<input type="text" name="product" value="<?php echo $row['product']; ?>">
<input type="text" name="amount" value="<?php echo $row['amount']; ?>">
<input type="text" name="available" value="<?php echo $row['available']; ?>">
<input type="submit" name="update" value="Update Product Information">
</form>
<?php
}
}
var_dump($_POST);
For the Undefined index just use a ternary in your form like so:
... value="<?php echo !empty($row['amount']) ? $row['amount'] : ''; ?>">
... value="<?php echo !empty($row['amount']) ? $row['available'] : ''; ?>">

Answer 2

Change these lines:
$stmt->bindParam(4, $productAmount);
$stmt->bindParam(5, $productAvailable);
to:
$stmt->bindParam(4, $_POST['amount']);
$stmt->bindParam(5, $_POST['available']);
So the result of cleaning up second part of your code would be this:
No need for a form name.
name="update" goes in the button's markup.
$_POST array now contains the new variables.
We check to make sure update is set before running the query.
<form method="POST">
<input type="text" name="id" value="<?php echo $newId; ?>">
<input type="text" name="first" value="<?php echo $first; ?>">
<input type="text" name="last" value="<?php echo $last; ?>">
<input type="text" name="product" value="<?php echo $product; ?>">
<input type="text" name="amount" value="<?php echo $row['amount']; ?>">
<input type="text" name="available" value="<?php echo $row['available']; ?>">
<button type="submit" name="update">Update Product Information</button>
</form>
<?php
}
if(isset($_POST['update'])) { // checking the button
$stmt = $dbc->prepare("UPDATE users SET first = ?, last = ?, product = ?, amount = ?, available = ? WHERE id = ?");
$stmt->bindParam(1, $_POST['first']);
$stmt->bindParam(2, $_POST['last']);
$stmt->bindParam(3, $_POST['product']);
$stmt->bindParam(4, $_POST['amount']); // now it is in the POST array
$stmt->bindParam(5, $_POST['available']); // same here
$stmt->bindParam(6, $newId);
$stmt->execute();
}