There is no duplication. It is the package below. There is no problem in face-to-face testing.
function MySQLModel(){
$link = null;
function mylink(){
// include 'conn.php';
// $link = mysqli_connect(HOST,USER,PASS,DBNAME) or die('Prompt: Database connection failed!');
define("HOST","localhost"); //Host name
define("USER","root"); //Account
define("PASS","root"); //Password
define("DBNAME","fanfancy"); //database name
$link = mysqli_connect(HOST,USER,PASS,DBNAME) or die('Prompt: Database connection failed!');
return $link;
}
$link = mylink();