Add each variable of a Query String to an array - php

Question

I have here the following output in a Query String:
add_to_cart.php?product_id=4&product_name=Pizza&quantity=1&additional_id[]=1&additional_quantity[]=3&additional_id[]=4&additional_quantity[]=5
I'm trying to set up an array with each of additional IDs and their respective quantities. Each ID corresponds to an additional product in the database in the table additionals, and I need to make a SQL query for each ID to get the price and the name of the additional and then show the price multiplicated with their quantity.
If I use:
foreach ($_GET['additional_id'] as $value)
{
echo "<p>{$value}</p>";
}
If the output is based in the example Query String above I get:
1
4
But I need to add each ID with their quantity inside of this array in the file add_to_cart.php:
$columns = array
(
'product_id_session' => $product_id_session,
'product_id' => $product_id,
'product_name' => $product_name,
'product_price' => $product_price,
'quantity' => $quantity,
'additional_id' => //Maybe I need a foreach here or another array to add all the additionals of Query String?
'additional_quantity' => //Here too?
'additional_name' => //Retrieved from database, like price below
'additional_price' => //Like additional_name, I will need to connect to database and get the price of each additional ID present in the Query String
);
I was trying to do something like:
add_to_cart.php?product_id=4&product_name=Pizza&quantity=1&additionals=additional_id[]=1&additional_quantity[]=3&additional_id[]=4&additional_quantity[]=5
This can be the right way? Maybe I can create an array with additionals and parse it to the columns array? And how to get the additional_price and additional_name for each additional ID present in Query String by a SQL connection to the table additionals? This is being very complicated for me. I appreciate any help!

Answer 1

Try
foreach ($_GET['additional_id'] as $key=>$value)
{
$id = htmlspecialchars($value);
$qty = htmlspecialchars($_GET['additional_quantity'][$key]);
echo "<p>ID: $id, Quantity: $qty</p>";
}
This assumes that the additional_id and additional_quantity arrays are of the same length and each index of additional_id matches the same index of additional_quantity.
You should probably be using another method to pass these sorts of values though. Doing it this way is really insecure and brittle.