Hello I need some help please!
I have a web page that currently inserts a record containing customerID, productID and quantity into the cart table if a user adds a product to their cart. However, if the user goes back to the shop and re-adds that same product to their cart. The php/mysql creates a new record regardless of what they have in their cart.
Current output in table:
customerID productID quantity
1 ABC12 3
1 ABC12 1
Expected output:
customerID productID quantity
1 ABC12 4
All help is greatly appreciated.
<!doctype html>
<html>
<head>
<title>Add Item to Cart</title>
<?php
session_start();
echo $_SESSION["user_id"];
$user_id = $_SESSION["user_id"];
$stockID = $_POST['stockNo'];
$quantity = $_POST['quantity'];
//connect to database.
include 'dbConnect.php';
//create MySQL insert command
$query1 = "insert into cart (customerID,stockID,quantity) values('$user_id','$stockID','$quantity');
//execute the MySQL statement
$result1 = mysqli_query($db,$query1);
?>
</head>
<body>
<?php include 'navBar.php'; ?>
<h1>Adding to cart....</h1>
<br>
<?php
if ($result1){
echo "Item has been added to your cart.";
}
else {
echo "Theres been a problem. Item was not added to your cart.";
}
?>
</body>
<?php //close connection to the database
mysqli_close();
?>
</html>