public $db_name;
public $db_user;
public $db_pass;
public $db_host;

public $connection;

 public function connection(){
    $this->db_host = HOST;
    $this->db_user = DB_USERNAME;
    $this->db_pass = DB_PASSWORD;
    $this->db_name = DB_NAME;

    $this->connection = new mysqli($this->db_host, $this->db_user, $this->db_pass, $this->db_name);
    //return new mysqli('localhost', 'root', '', 'dbcdce');

    //return $this->connect($this->db_host, $this->db_user, $this->db_pass, $this->db_name);
}

function connect($host, $user, $pass, $db_name) {

    $this->connection = new mysqli($host, $user, $pass, $db_name);

    if ( mysqli_connect_errno() ) {
        printf("Connection failed: %s", mysqli_connect_error());
        exit();
    }

    return $this->connection;

}

public function query($sql)
    {
    return $this->connection->query($sql);
    }