Code:
// Define database connection constants
define('DB_HOST', 'localhost');
define('DB_USER', 'username');//put in username
define('DB_PASSWORD', password');//put in password
define('DB_NAME', 'databaseName'); //put in DB name
//connect to database
$dbc = mysqli_connect(DB_HOST, DB_USER, DB_PASSWORD, DB_NAME)
or die('Error connecting to MySQL server.');
//display existing entries
$query = "SELECT field FROM dataBase";
$result = mysqli_query($dbc, $query);
$row = mysqli_fetch_array($result);
define constants for the database in case you change your password you wont have to change it on every page, and then put constants on seperate page and link to it.