Delete button not working in PHP/MySQL - php

Question

My query is not working in deleteartikel.php, it doesn't delete anything out of the database.
In form.php I made a delete button but it doesn't delete the row itself. I can't find the mistake.
form.php
<?php
include 'dbconnect.php';
$sql = "SELECT * FROM artikel";
$result = $conn->query($sql);
if ($result->num_rows > 0) {
// output data of each row
while($row = $result->fetch_assoc()) {
echo "<tr>";
echo "<td>".$row['Productcode']."</td>";
echo "<td>".$row['Product']."</td>";
echo "<td>".$row['Type']."</td>";
echo "<td>".$row['Fabriekcode']."</td>";
echo "<td>".$row['Inkoopprijs']."</td>";
echo "<td>".$row['Verkoopprijs']."</td>";
echo "<td><form action='deleteartikel.php' method='post'>
<input type='submit' name='delete' value='delete'>
</form></td>";
}
} else {
echo "0 results";
}
$conn->close();
?>
</tbody>
</table>
</div>
<!-- Footer navigatie -->
<footer>©ToolsForEver 2017 alle rechten voorbehouden.</footer>
</body>
</html>
deleteartikel.php
<?php
if(isset($_POST['delete'])) {
include('dbconnect.php');
$productcode = $_POST['Productcode'];
$conn->query("DELETE FROM artikel WHERE Productcode = '$productcode'");
header('Location: artikel.php');
}
?>

Answer 1

You never post the product code so the query fails, there is no value sent. You have to add a hidden field to your form:
echo "<form action='deleteartikel.php' method='post'>
<input type='hidden' name='Productcode' value='". $row['Productcode'] ."'>
<input type='submit' name='delete' value='delete'>
</form>";
Little Bobby says your script is at risk for SQL Injection Attacks. Learn about prepared statements for MySQLi. Even escaping the string is not safe! Don't believe it?
In addition, as Fred pointed out above, a form cannot be the child of a table cell, so you need to refactor your code such that you have a form containing a table for each row.
Error checking in deleteartikel.php would have revealed the issue with the missing value for your query. Without error checking in the script you can find the errors in your web server's error logs.