Please find below code for MySQL database connection within PHP old version.

$host = “localhost”;
$user = “dbuser”;
$password = “dbpass”;
$dbname = “dbname”;

$link = mysql_connect($host, $user, $password);
if (!$link) {
die(‘Could not connect: ‘ . mysql_error());
}
mysql_select_db($dbname, $link);

$query = “SELECT * FROM table_name”;

$r = mysql_query($query) or die(mysql_error());