how do I check if mysqli connection is working?

Question

I am really new on php and I am trying to create my own php shop cart. After some research I got myself stuck in the "function products" below because seems to me it is not working properly. I expect to see the names of my products on my mysql database but it is not showing anything. My user name is noivaemd_etalhes, I am using my correct password and my database name is noivaemd_cart and I created on this database the table called Products with my list of products available. Can anybody help me to figure out what am I doing wrong on the php instructions below???? I appreciate any help.

<?php 

session_start();
$page = 'index.php';

function products()  {
        $con = mysqli_connect("localhost", "noivaemd_etalhes", "mypassword", "noivaemd_cart") or die (mysqli_error());
        $res = mysqli_query($con, "SELECT id, name, description, price FROM Products WHERE quantity > 0 ORDER BY id DESC");
        if (mysqli_num_rows($res)==0) {
        echo "<font family=verdana><font size=6px><font color= #90882C><font style=normal><font variant= normal><br>No products available<br></font>";
            }
        else{
        while($get_row = mysqli_fetch_assoc($res)) {
                echo '<p>'.$res['name'].'</p>';
        }
    }
}

?>

Answer 1

This code:

while ($get_row = mysqli_fetch_assoc($res)) {
    echo '<p>'.$res['name'].'</p>';
}

Should be:

while ($get_row = mysqli_fetch_assoc($res)) {
    echo '<p>'.$get_row ['name'].'</p>';
}

As your title ask also tell how to check if the mysqli database connection is successful you can use the below code:

$con = mysqli_connect("localhost","my_user","my_password","my_db");

// Check connection
if (mysqli_connect_errno()) {
  echo "Failed to connect to MySQL: " . mysqli_connect_error();
}

Reference link: http://www.php.net/manual/en/function.mysqli-connect.php