functions/

<?php
//config-db.php
define('DB_SERVER','localhost') ;
define('DB_USER','root');
define('DB_PASS','toor');
define('DB_DATABASE','myweb');


?>

















<?php
//userAPI.php
include "config-db.php" ;
class userAPI{
public $db;

function __contruct(){

$this->db=new mysqli(DB_SERVER,DB_USER,DB_PASS,DB_DATABASE);
if ($this->db->connect_error){
die ("error connect database!");
exit;

}


}
function login($username,$password){

$select=$this->db->query("select * from users where username='$username' and password='$username'") or die ("c'ant select!!");
if($select->num_rows>0){
return true;}
else{
print "خطأفي الاسم اوكلمة المرور";
return false;
}
}
function update($username,$password,$id){

if (!isset($id)){
print "bad request";
}
$id=intval($id);
if ($id='0'){
print "bad request";
}
else{

$select=$this->db->query("UPDATE users set username='$username' and password='$username' where id='$id'") or die ("c'ant select!!");

}



}

function select(){

$select=$this->db->query("select * from users where id='$id'") or die ("c'ant select!!");
$fetch=$select->fetch_array('MYSQLI_ASSOC');
$username_db=$fetch['username'];
$password_db=$fetch['password'];
$id_db=$fetch['id'];
$lvl_db=$fetch['lvl'];

}



}



$dz=new userAPI();
$dz->login('dz','dz');


?>

















:========problleme=========:

 Fatal error: Call to a member function query() on a non-object in /var/www/html/site/admin/functions/userAPI.php on line 19