getting Undefined Index error.

[vk7]

I am working on ecommerce website. whenever i logged in to my website, In products.php page i gets an error (Undefined Index error: user_id) in adding item to a cart. and i gets that error in line 4 of 'check-if-added.php' files products.phpcheck-if-added.php

[requinix]

Attachments are annoying. This goes a lot easier if you post the relevant portion of the code directly in the post.

 

I'm guessing it happens when a user is not logged in?

[vk7]

Attachments are annoying. This goes a lot easier if you post the relevant portion of the code directly in the post.

 

I'm guessing it happens when a user is not logged in?

The problems happens when the user is logged in. here i am posting code of check-if-added.php:

 

<?php

//This code checks if the product is added to cart.

function check_if_added_to_cart($item_id) {

    $user_id = $_SESSION['user_id']; //We'll get the user_id from the session

    require("includes/common.php");

    // We will select all the entries from the user_items table where the item_id is equal to the item_id we passed to this function, user_id is equal to the user_id in the session and status is 'Added to cart'

    $query = "SELECT * FROM users_items WHERE item_id='$item_id' AND user_id ='$user_id' and status='Added to cart'";

    $result = mysqli_query($con, $query) or die(mysqli_error($con));

    while($row = mysqli_fetch_array($result)){

        if (mysqli_num_rows($result) >= 1) {

            return 1;

        } else {

            return 0;

       }

    }

}

 

?>

[requinix]

Presumably the error is pointing to

$user_id = $_SESSION['user_id']; //We'll get the user_id from the session

"Undefined index" means there is no user_id in $_SESSION. Either the user is logged out or your code is looking at the wrong array index.