public function getStudents($order, $start, $limit, $search = '')
    {
        var_dump($order);
        $query = "SELECT
                    name, secondName, groupNumber, gender, birthYear, summary, email, local
                  FROM
                    students ";
        if(!empty($search)){
            $query .= "WHERE
                   name LIKE :search OR 
                   secondName  LIKE :search OR 
                   groupNumber  LIKE :search OR 
                   summary  LIKE :search ";
        }
        $query .= " ORDER BY 
                    :order
                  LIMIT :start, :end";
        
        $stmt = $this->dbh->prepare($query);
        
        $stmt->bindValue(':order', $order);
        $stmt->bindValue(':start', $start);
        $stmt->bindValue(':end', $limit);
        
        if(!empty($search)) $stmt->bindValue(':search', $search);
        
        $stmt->execute();
        $result = $stmt->fetchAll(\PDO::FETCH_CLASS,\App\Models\Student::class);
        
        return $result;
    }