Give value to Database by Pressing button - php

Question

So i ran into some trouble not to long ago. As a student i am relativly new to programming and thus i often visit sites like these for help. My question is how can i add value to database by pressing a button. For me the problem here is that the button has a javavscript function to print. So in other words i want the button to have 2 functions, one that prints the page (which i already have) and one that adds value to the database. The purpose to adding the value to database is so people can see that its already been printed before.
So essentialy what i am asking for is how can i give a button 2 functions (one which is Javascript) and show people that the button is used(in this case, that it has been printed). All help will be appreciated very much.
My code is as following:
<?php
$servername = "localhost";
$username = "root";
$password = "";
$dbname = "depits";
// Create connection
$conn = mysqli_connect($servername, $username, $password, $dbname);
// Query the database
$resultSet = $conn->query("SELECT * FROM orders");
// Count the returned rows
if($resultSet->num_rows != 0){
// Turn the results into an Array
while($rows = $resultSet->fetch_assoc())
{
$id = $rows['id'];
$naam = $rows['naam'];
$achternaam = $rows['achternaam'];
$email = $rows['email'];
$telefoon = $rows['telefoon'];
$bestelling = $rows['bestelling'];
echo "<p>Name: $naam $achternaam<br />Email: $email<br />Telefoon: $telefoon<br /> Bestelling: $bestelling<br /> <a href='delete.php?del=$id'>Delete</a> <input type='button' onclick='window.print()' value='Print Table' /> </p>";
}
// Display the results
}else{
echo "Geen bestellingen";
}
?>

Answer 1

This would aquire 2 tasks:
Is that you bind a function to the click handler of the button.
Although it is bad practice to use function calls directly, in your case this would be that you replace the window.print() by a custom javascript function.
In that javascript function, you execute the window.print() again, where-after you do the next step in the logic: sending data to PHP.
With ajax you can archieve this.
With a parameter in the function you can pass what the ID of the current row is, which need to be passed to PHP.
You need to create another PHP script, that will be called by tje AJAX script.
In that PHP script you will do the required updates to the database.

Answer 2

Ok There is a lot of ways you can do it but here is how i would do it :
<?php
$servername = "localhost";
$username = "root";
$password = "";
$dbname = "depits";
// Create connection
$conn = mysqli_connect($servername, $username, $password, $dbname);
// Query the database
$resultSet = $conn->query("SELECT * FROM orders");
// Count the returned rows
if($resultSet->num_rows != 0){
// Turn the results into an Array
while($rows = $resultSet->fetch_assoc())
{
$id = $rows['id'];
$naam = $rows['naam'];
$achternaam = $rows['achternaam'];
$email = $rows['email'];
$telefoon = $rows['telefoon'];
$bestelling = $rows['bestelling'];
//first you call a custom javascript function after the 'onclick'. I believe you'll have to pass a variable as an argument (like $id).
echo "<p>Name: $naam $achternaam<br />Email: $email<br />Telefoon: $telefoon<br /> Bestelling: $bestelling<br /> <a href='delete.php?del=$id'>Delete</a> <input type='button' onclick='print_table($id)' value='Print Table' /> </p>";
}
// Display the results
}else{
echo "Geen bestellingen";
}
?>
Then you write this function in the header of your page
<script>
function print_table(id)
{
//print your document
window.print();
//send your data
xmlhttp=new XMLHttpRequest();
xmlhttp.open("GET","http://www.domaine.com/directories/printed_table.php?id=" + id;
xmlhttp.send();
}
</script>
Then you write your file printed_table.php where you store 1 if printed or 0 if not printed. I don't understand german so i don't know where you store your printed variable but it goes like this:
<?php
$servername = "localhost";
$username = "root";
$password = "";
$dbname = "depits";
// Create connection
$conn = mysqli_connect($servername, $username, $password, $dbname);
// Query the database
$id = $_GET['id'];
$resultSet = $conn->query("UPDATE `orders` SET `printed` = 1 WHERE `id` = `$id`");
?>
This should work. Just be careful and check the $_GET['id'] before to use it for security purposes. like you can use the php function is_int(). Depending of the security level you need you might want to secure this code a little more.