I am working on ecommerce website. Whenever I logged in to website and redirects to products.php page where products is listed, an error ‘Undefined Index: user_id’ occurs in checking the products been added or not added to cart.
here the error occurs in line 4 of check-if-added.php, code is given below.
[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’
$query = “SELECT * FROM users_items WHERE user_id =’$user_id’ AND item_id=’$item_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($result) >= 1) {
return 1;
} else {
return 0;
}
}
}
?>[/php]
and the code for products.php page where the products is listed :
[php]<?php
session_start();
require(“includes/common.php”);
if (!isset($_SESSION[‘email’]))
header(‘location: index.php’);
?>
Products | BookMyKart<body>
<?php
include 'includes/header.php';
include 'includes/check-if-added.php';
?>
<div class="container" id="content">
<!-- Jumbotron Header -->
<div class="jumbotron home-spacer" id="products-jumbotron">
<center><h1 style="letter-spacing: 3px;">Welcome to our Online Store!</h1></center>
<p>We have the best cameras, watches and shirts for you. No need to hunt around, we have all in one place.</p>
</div>
<hr>
<div class="row text-center" id="cameras">
<div class="col-md-3 col-sm-6 home-feature">
<div class="thumbnail">
<img src="img/5.jpg" alt="">
<div class="caption">
<h3>Cannon EOS </h3>
<p>Price: Rs. 36000 </p>
<?php if (!isset($_SESSION['email'])) { ?>
<p><a href="#myModal" role="button" data-toggle="modal" class="btn btn-primary btn-block">Buy Now</a></p>
<?php
} else {
//We have created a function to check whether this particular product is added to cart or not.
if (check_if_added_to_cart(1)) { //This is same as if(check_if_added_to_cart != 0)
echo '<a href="#" class="btn btn-block btn-success" disabled>Added to cart</a>';
} else {
?>
<a href="cart-add.php?id=1" name="add" value="add" class="btn btn-block btn-primary">Add to cart</a>
<?php
}
}
?>
</div>
</div>
</div>
<div class="col-md-3 col-sm-6 home-feature">
<div class="thumbnail">
<img src="img/2.jpg" alt="">
<div class="caption">
<h3>Nikon EOS </h3>
<p>Price: Rs. 40000</p>
<?php if (!isset($_SESSION['email'])) { ?>
<p><a href="#myModal" role="button" data-toggle="modal" class="btn btn-primary btn-block">Buy Now</a></p>
<?php
} else {
//We have created a function to check whether this particular product is added to cart or not.
if (check_if_added_to_cart(2)) { //This is same as if(check_if_added_to_cart != 0)
echo '<a href="#" class="btn btn-block btn-success" disabled>Added to cart</a>';
} else {
?>
<a href="cart-add.php?id=2" name="add" value="add" class="btn btn-block btn-primary">Add to cart</a>
<?php
}
}
?>
</a>
</div>
</div>
</div>
<div class="col-md-3 col-sm-6 home-feature">
<div class="thumbnail">
<img src="img/3.jpg" alt="">
<div class="caption">
<h3>Sony DSLR</h3>
<p>Price: Rs. 50000</p>
<?php if (!isset($_SESSION['email'])) { ?>
<p><a href="#myModal" role="button" data-toggle="modal" class="btn btn-primary btn-block">Buy Now</a></p>
<?php
} else {
//We have created a function to check whether this particular product is added to cart or not.
if (check_if_added_to_cart(3)) { //This is same as if(check_if_added_to_cart != 0)
echo '<a href="#" class="btn btn-block btn-success" disabled>Added to cart</a>';
} else {
?>
<a href="cart-add.php?id=3" name="add" value="add" class="btn btn-block btn-primary">Add to cart</a>
<?php
}
}
?>
</a>
</div>
</div>
</div>
<div class="col-md-3 col-sm-6 home-feature">
<div class="thumbnail">
<img src="img/4.jpg" alt="">
<div class="caption">
<h3>Olympus DSLR</h3>
<p>Price: Rs. 50000</p>
<?php if (!isset($_SESSION['email'])) { ?>
<p><a href="#myModal" role="button" data-toggle="modal" class="btn btn-primary btn-block">Buy Now</a></p>
<?php
} else {
//We have created a function to check whether this particular product is added to cart or not.
if (check_if_added_to_cart(4)) { //This is same as if(check_if_added_to_cart != 0)
echo '<a href="#" class="btn btn-block btn-success" disabled>Added to cart</a>';
} else {
?>
<a href="cart-add.php?id=4" name="add" value="add" class="btn btn-block btn-primary">Add to cart</a>
<?php
}
}
?>
</a>
</div>
</div>
</div>
</div>
<div class="row text-center" id="watches">
<div class="col-md-3 col-sm-6 home-feature">
<div class="thumbnail">
<img src="img/18.jpg" alt="">
<div class="caption">
<h3>Titan Model1</h3>
<p>Price: Rs. 13000</p>
<?php if (!isset($_SESSION['email'])) { ?>
<p><a href="#myModal" role="button" data-toggle="modal" class="btn btn-primary btn-block">Buy Now</a></p>
<?php
} else {
//We have created a function to check whether this particular product is added to cart or not.
if (check_if_added_to_cart(5)) { //This is same as if(check_if_added_to_cart != 0)
echo '<a href="#" class="btn btn-block btn-success" disabled>Added to cart</a>';
} else {
?>
<a href="cart-add.php?id=5" name="add" value="add" class="btn btn-block btn-primary">Add to cart</a>
<?php
}
}
?>
</a>
</div>
</div>
</div>
<div class="col-md-3 col-sm-6 home-feature">
<div class="thumbnail">
<img src="img/19.jpg" alt="">
<div class="caption">
<h3>Titan Model2</h3>
<p>Price: Rs. 3000</p>
<?php if (!isset($_SESSION['email'])) { ?>
<p><a href="#myModal" role="button" data-toggle="modal" class="btn btn-primary btn-block">Buy Now</a></p>
<?php
} else {
//We have created a function to check whether this particular product is added to cart or not.
if (check_if_added_to_cart(6)) { //This is same as if(check_if_added_to_cart != 0)
echo '<a href="#" class="btn btn-block btn-success" disabled>Added to cart</a>';
} else {
?>
<a href="cart-add.php?id=6" name="add" value="add" class="btn btn-block btn-primary">Add to cart</a>
<?php
}
}
?>
</a>
</div>
</div>
</div>
<div class="col-md-3 col-sm-6 home-feature">
<div class="thumbnail">
<img src="img/20.jpg" alt="">
<div class="caption">
<h3>HMT Milan</h3>
<p>Price: Rs. 8000 </p>
<?php if (!isset($_SESSION['email'])) { ?>
<p><a href="#myModal" role="button" data-toggle="modal" class="btn btn-primary btn-block">Buy Now</a></p>
<?php
} else {
//We have created a function to check whether this particular product is added to cart or not.
if (check_if_added_to_cart(7)) { //This is same as if(check_if_added_to_cart != 0)
echo '<a href="#" class="btn btn-block btn-success" disabled>Added to cart</a>';
} else {
?>
<a href="cart-add.php?id=7" name="add" value="add" class="btn btn-block btn-primary">Add to cart</a>
<?php
}
}
?>
</a>
</div>
</div>
</div>
<div class="col-md-3 col-sm-6 home-feature">
<div class="thumbnail">
<img src="img/21.jpg" alt="">
<div class="caption">
<h3>Faber Luba </h3>
<p>Price: Rs. 18000 </p>
<?php if (!isset($_SESSION['email'])) { ?>
<p><a href="#myModal" role="button" data-toggle="modal" class="btn btn-primary btn-block">Buy Now</a></p>
<?php
} else {
//We have created a function to check whether this particular product is added to cart or not.
if (check_if_added_to_cart(8)) { //This is same as if(check_if_added_to_cart != 0)
echo '<a href="#" class="btn btn-block btn-success" disabled>Added to cart</a>';
} else {
?>
<a href="cart-add.php?id=8" name="add" value="add" class="btn btn-block btn-primary">Add to cart</a>
<?php
}
}
?>
</a>
</div>
</div>
</div>
</div>
<div class="row text-center" id="shirts">
<div class="col-md-3 col-sm-6 home-feature">
<div class="thumbnail">
<img src="img/22.jpg" alt="">
<div class="caption">
<h3>H&W </h3>
<p>Price: Rs. 800 </p>
<?php if (!isset($_SESSION['email'])) { ?>
<p><a href="#myModal" role="button" data-toggle="modal" class="btn btn-primary btn-block">Buy Now</a></p>
<?php
} else {
//We have created a function to check whether this particular product is added to cart or not.
if (check_if_added_to_cart(9)) { //This is same as if(check_if_added_to_cart != 0)
echo '<a href="#" class="btn btn-block btn-success" disabled>Added to cart</a>';
} else {
?>
<a href="cart-add.php?id=9" name="add" value="add" class="btn btn-block btn-primary">Add to cart</a>
<?php
}
}
?>
</a>
</div>
</div>
</div>
<div class="col-md-3 col-sm-6 home-feature">
<div class="thumbnail">
<img src="img/23.jpg" alt="">
<div class="caption">
<h3>Luis Phil</h3>
<p>Price: Rs. 1000</p>
<?php if (!isset($_SESSION['email'])) { ?>
<p><a href="#myModal" role="button" data-toggle="modal" class="btn btn-primary btn-block">Buy Now</a></p>
<?php
} else {
//We have created a function to check whether this particular product is added to cart or not.
if (check_if_added_to_cart(10)) { //This is same as if(check_if_added_to_cart != 0)
echo '<a href="#" class="btn btn-block btn-success" disabled>Added to cart</a>';
} else {
?>
<a href="cart-add.php?id=10" name="add" value="add" class="btn btn-block btn-primary">Add to cart</a>
<?php
}
}
?>
</a>
</div>
</div>
</div>
<div class="col-md-3 col-sm-6 home-feature">
<div class="thumbnail">
<img src="img/24.jpg" alt="">
<div class="caption">
<h3>John Zok</h3>
<p>Price: Rs. 1500</p>
<?php if (!isset($_SESSION['email'])) { ?>
<p><a href="#myModal" role="button" data-toggle="modal" class="btn btn-primary btn-block">Buy Now</a></p>
<?php
} else {
//We have created a function to check whether this particular product is added to cart or not.
if (check_if_added_to_cart(11)) { //This is same as if(check_if_added_to_cart != 0)
echo '<a href="#" class="btn btn-block btn-success" disabled>Added to cart</a>';
} else {
?>
<a href="cart-add.php?id=11" name="add" value="add" class="btn btn-block btn-primary">Add to cart</a>
<?php
}
}
?>
</a>
</div>
</div>
</div>
<div class="col-md-3 col-sm-6 home-feature">
<div class="thumbnail">
<img src="img/25.jpg" alt="">
<div class="caption">
<h3>Jhalsani</h3>
<p>Price Rs. 1300</p>
<?php if (!isset($_SESSION['email'])) { ?>
<p><a href="#myModal" role="button" data-toggle="modal" class="btn btn-primary btn-block">Buy Now</a></p>
<?php
} else {
//We have created a function to check whether this particular product is added to cart or not.
if (check_if_added_to_cart(12)) { //This is same as if(check_if_added_to_cart != 0)
echo '<a href="#" class="btn btn-block btn-success" disabled>Added to cart</a>';
} else {
?>
<a href="cart-add.php?id=12" name="add" value="add" class="btn btn-block btn-primary">Add to cart</a>
<?php
}
}
?>
</a>
</div>
</div>
</div>
</div>
<hr>
</div>
<?php include("includes/footer.php"); ?>
<?php include("modal.php"); ?>
</body>