public function insertStudent(Student $Student)
 {
     $sql = "INSERT INTO Student  VALUES (?,?,?,?,?,?,?,?)";
     $params = array($Student->getStudentId(), $Student->getFirstName(), $Student->getLastName(), $Student->getDob()->format("y/m/d"), $Student->getGender(), $Student->getUsername(), $Student->getPassword(), $Student->isApproved());
     $stmt = $this->db->prepare($sql);
     $res = $stmt->execute($params);
     $Student->setStudentId($this->getLastId());
     return $res;
 }