@Override
  public List<User> queryUsers() {

    return sqlSessionDao.selectList("com.bytebeats.codelab.mybatis.mapper.UserMapper.selectList");
  }
  @Override
  public User queryById(long id) {

    return sqlSessionDao.selectOne(
        "com.bytebeats.codelab.mybatis.mapper.UserMapper.selectById", id);
  }
  @Override
  public int delete(long id) {

    return sqlSessionDao.delete("com.bytebeats.codelab.mybatis.mapper.UserMapper.deleteById", id);
  }
  @Override
  public int update(User user) {

    return sqlSessionDao.update("com.bytebeats.codelab.mybatis.mapper.UserMapper.updateById", user);
  }
  @Override
  public int insertBatch(List<User> list) {

    return sqlSessionDao.insert(
        "com.bytebeats.codelab.mybatis.mapper.UserMapper.batchInsert", list);
  }
  @Override
  public long insert(User user) {

    return sqlSessionDao.insert("com.bytebeats.codelab.mybatis.mapper.UserMapper.insert", user);
  }