PHP how to check if product exists in cart - php

Question

Before add it to cart i want to check if that item already exist. If item exist i dont want twice to show the some item in looping. Just increment quantity of existing item in array session.
Session array with items in cart:
Array
(
[0] => Array
(
[id] => 1
[qty] => 1
)
[1] => Array
(
[id] => 1
[qty] => 1
)
)
On Cart page where am looping items form cart i have this:
<?php
$db = require('database.php');
$cart_items = isset($_SESSION['cart']) ? $_SESSION['cart'] : null;
$products = array();
if($cart_items):
foreach ($cart_items as $key => $value)
{
$products[$key] = $value;
$id = (int) $value['id'];
$result = $db->query("SELECT * FROM products WHERE id=$id");
while($row = $result->fetch_object())
{
$products[$key]['id'] = $row->id;
$products[$key]['name'] = $row->name;
$products[$key]['price'] = number_format($row->price, 2);
// check if item exists
// this dont work i dont know how to check this
if($id == $row->id && $value['qty'] == 1)
{
$products[$key]['qty']++;
}
}
}
endif;
?>
And fronted part where i loop cart products:
<tbody>
<?php if($products): ?>
<?php foreach ($products as $product): ?>
<tr>
<td><?= $product['id'];?></td>
<td><?= $product['name'];?></td>
<td><?= $product['price'];?> Eur</td>
<td><input type="text" name="qty" value="<?= $product['qty']; ?>" size="5"> </td>
<td> <i class="glyphicon glyphicon-remove"></i> Remove </td>
</tr>
<?php endforeach; ?>
<?php endif;?>
</tbody>
So problem is when i click 2 times on item with id = 1 i get two new table rows with the some products. My idea is when i click 2 times on product id = 1 just increment quantity on existing product in cart.
Any sugestion for this ?

Answer 1

First of all, use array_column() function to get all the existing product ids from the $products array. And then check whether the particular item exists in the $products array or not, and update the product and/or quantity details accordingly.
So your while() loop should be like this:
while($row = $result->fetch_object()){
$ids = array_column($products, 'id');
if(in_array($row->id, $ids)){
$products[$key]['qty']++;
}else{
$products[$key]['id'] = $row->id;
$products[$key]['name'] = $row->name;
$products[$key]['price'] = number_format($row->price, 2);
$products[$key]['qty'] = 1;
}
}
Also, remove this statement from your foreach loop,
$products[$key] = $value;
Updated:
From OP's comment,
Now problem is in looping products in cart, when i loop products in cart i have duplicate product becouse i add one product 2 times and update quantity. How to prevent double looping one item in cart! If i press 10 times product with id = 1. I dont want 10 new loop items in list i want only update quantity value. Prevent the some item loop in <tr><td> ...</td></tr> ...
Change your code inside the if block in the following way,
$unique_ids = array_unique(array_column($cart_items, 'id'));
foreach ($cart_items as $key => $value){
if(!in_array($value['id'], $unique_ids)) continue;
$id = (int) $value['id'];
$result = $db->query("SELECT * FROM products WHERE id=$id");
while($row = $result->fetch_object()){
$ids = array_column($products, 'id');
if(in_array($row->id, $ids)){
$products[$key]['qty']++;
}else{
$products[$key]['id'] = $row->id;
$products[$key]['name'] = $row->name;
$products[$key]['price'] = number_format($row->price, 2);
$products[$key]['qty'] = 1;
}
}
$key = array_search($value['id'],$unique_ids);
unset($unique_ids[$key]);
}