Storing multiple items into a session - php

Question

I am trying to store multiple items into a session. I am posting an items from a form like so:
<?php
$product_id = $_GET['product_id'];
$sql = "SELECT * FROM Products WHERE product_id = $product_id";
$result = $conn->query($sql);
if($result->num_rows > 0){
while($row = $result->fetch_assoc()){
echo '<img src=' . $row['product_img'] . ' />';
echo '<div class="title">'. $row['product_name'] .'</div>';
echo '<div class="title">'. $row['product_price'] .'</div>';
echo '<div class="title">'. $row['product_sku'] .'</div>';
echo '<div class="title">'. $row['product_description'] .'</div>';
echo '<form action="addToCart.php" method="post">
<input type="hidden" name="product_img" value="' . $row['product_img'] . '" />
<input type="hidden" name="product_id" value="' . $row['product_id'] . '" />
<input type="hidden" name="product_name" value="' . $row['product_name'] . '" />
<input type="hidden" name="product_price" value="' . $row['product_price'] . '" />
<input type="hidden" name="product_sku" value="' . $row['product_sku'] . '" />
<input type="hidden" name="product_description" value="' . $row['product_description'] . '" />
<input type="submit" name="Submit">
</form>';
}
} else{
echo "0 Results";
}
?>
addToCart.php looks like this:
<?php
if (isset($_POST['Submit'])) {
$_SESSION['product_img'] = $_POST['product_img'];
$_SESSION['product_id'] = $_POST['product_id'];
$_SESSION['product_name'] = $_POST['product_name'];
$_SESSION['product_price'] = $_POST['product_price'];
$_SESSION['product_sku'] = $_POST['product_sku'];
$_SESSION['product_description'] = $_POST['product_description'];
}
?>
So the above is now setting the items into the session (So I believe). I am then outputting the item from the stored data in basket.php
<?php echo '<img src=' . $_SESSION['product_img'] . ' />'; ?>
<?php echo $_SESSION['product_id'];?>
<?php echo $_SESSION['product_name'];?>
<?php echo $_SESSION['product_price'] ?>
<?php echo $_SESSION['product_sku']; ?>
<?php echo $_SESSION['product_description']; ?>
the Issue I have is whenever I add another item it overrides the previous item? I know I need to use an array to store multiple items but I have tried a few different things but I am struggling to understand.

Answer 1

You can use [] to store them in array:
$_SESSION['product_img'][] = $_POST['product_img'];
$_SESSION['product_id'][] = $_POST['product_id'];
$_SESSION['product_name'][] = $_POST['product_name'];
$_SESSION['product_price'][] = $_POST['product_price'];
$_SESSION['product_sku'][] = $_POST['product_sku'];
$_SESSION['product_description'][] = $_POST['product_description']
Now, try to see what are in each array:
var_dump($_SESSION['product_id']);

Answer 2

It is possible to store your Session Data as nested array. In your case, since it is a Shopping Cart, you may want to build your Arrays using the ID of the Product; that way you are certain that no product will override the other (so long as they don't have the same product_id values.... Below is an example of how you may do that:
<?php
//FIRST CHECK IF SESSION EXIST BEFORE STARTING IT:
if (session_status() == PHP_SESSION_NONE || session_id() == '') {
session_start();
}
if (isset($_POST['Submit'])) {
$product_id = htmlspecialchars(trim($_POST['product_id']));
$product_img = htmlspecialchars(trim($_POST['product_img']));
$product_sku = htmlspecialchars(trim($_POST['product_sku']));
$product_name = htmlspecialchars(trim($_POST['product_name']));
$product_price = htmlspecialchars(trim($_POST['product_price']));
$product_description = htmlspecialchars(trim($_POST['product_description']));
if(!isset($_SESSION['products'])){
$_SESSION['products'] = array();
}
if(!isset($_SESSION['products'][$product_id])){
$_SESSION['products'][$product_id] = array();
}
$_SESSION['products'][$product_id]['product_id'] = $product_id;
$_SESSION['products'][$product_id]['product_img'] = $ $product_img;
$_SESSION['products'][$product_id]['product_name'] = $product_name;
$_SESSION['products'][$product_id]['product_price'] = $product_price;
$_SESSION['products'][$product_id]['product_sku'] = $product_sku;
$_SESSION['products'][$product_id]['product_description'] = $product_description;
}
And anywhere else (another Script perhaps) you could access your Data like so:
<?php
$output = "";
$storedProductData = $_SESSION['products'];
if(!empty($storedProductData)){
foreach($storedProductData as $product_id=>$productData){
$output .= "<img src='{$productData['product_img']}' />" . PHP_EOL;
$output .= "<span id='generic-class'>{$productData['product_id']}</span>" . PHP_EOL;
$output .= "<span id='generic-class'>{$productData['product_name']}</span>" . PHP_EOL;
$output .= "<span id='generic-class'>{$productData['product_price']}</span>" . PHP_EOL;
$output .= "<span id='generic-class'>{$productData['product_sku']}</span>" . PHP_EOL;
$output .= "<span id='generic-class'>{$productData['product_description']}</span>" . PHP_EOL;
}
}