PHP MySQL connection script in different file

I have set up a MySQL table that has two columns, name and age, and inserted the data “steve” and 22. If I have the following program called home.php and run it in my browser, everything works fine.

<?php $servername = “localhost”; $username = “myusername”; $password = “mypassword”; $dbname = “mydbname”;

$conn = new mysqli($servername, $username, $password, $dbname);

if ($conn->connect_error) { die("Connection failed: " . $conn->connect_error); } //lines above get moved to db_connect.php
$sql = “SELECT name FROM my_table WHERE age = 22”; $result = $conn->query($sql);

if ($result->num_rows > 0) { while($row = $result->fetch_assoc()) { echo "the name is: " . $row[“name”]. “<br>”; } } else { echo “0 results”; } $conn->close(); ?>

However, if I move the database connection part to a file, db_connect.php inside a folder and place this code at the top of home.php:

require_once ‘\var\www\my_website\private_database\db_connect.php’;

The browser no longer outputs “the name is steve”

Can someone please help me to understand why it works when I put the database connection variables inside the program, but not when I try to use require_once. I’m using LEMP. Thank you.