java sql 练习

    //根据用户名查询用户信息
    public User selectUser(String username) throws SQLException {
        String sql = "select * from user where username = ?";
        User user = qr.query(sql,new BeanHandler(User.class),username);
        return user;
    }

    //查询所有的用户信息
    public List selectAllUser() throws SQLException {
        String sql = "select * from user";
        List userList = qr.query(sql, new BeanListHandler(User.class));
        return userList;
    }
    //修改指定用户的信息
    public int updatePassword(String username,String password) throws SQLException {
        String sql = "update user set password=? where username = ?";
        int update = qr.update(sql, password, username);
        return update;
    }

    //根据用户名查询用户信息
    @Test
    public void testSelectUser() throws SQLException {
        User user = userDao.selectUser("月灵");
        System.out.println(user.toString());
    }

    //查询所有的用户信息
    @Test
    public void testSelectAllUser() throws SQLException {
        List userList = userDao.selectAllUser();
        for (User user: userList) {
            System.out.println(user.toString());
        }
    }

    //修改用户信息
    @Test
    public void testUpdatePassword() throws SQLException {
        int update = userDao.updatePassword("月灵", "114514");
        String isOk = update > 0 ? "修改成功!" : "修改失败";
        System.out.println(isOk);
    }

2.

3.

重新查询月灵 发现password 已经更改