MyBatis的註解，主要是用於替換對映檔案。對映檔案中無非存放在增刪改查的sql對映標籤。所以，MyBatis註解，就是要替換對映檔案中的SQL標籤。
MyBatis官方文件中指出，若要真正想發揮MyBatis功能，還是要用對映檔案。所以官方並不建議使用MyBatis註解式開發。 

MyBatis的註解主要是在介面方法的的上面的  注意的是註解括號後面不需要打分號。

介面類   ↓

/**
*新增
**/
@Insert("INSERT INTO `books`.`t_user` (`uid`, `uname`, `upwd`) VALUES(#{uid},#{uname}, #{upwd}) ")
    public void adduser(t_user user);
/**
*修改
**/
@Update("UPDATE  t_user SET   uname = #{uname}, upwd = #{upwd} WHERE uid = #{uid}")
public void edituser( t_user user);
/**
*刪除
**/
@Delete("DELETE  FROM t_user WHERE `uid` = #{uid}")
public void  deleteuser(String uid);
/**
*條件查詢
**/
@Select(" select * from t_user where uname=#{uname}")
public  t_user alluserByname(String uname);
/**
*查詢所有
**/
@Select("select * from t_user")
public List<t_user> alluser();
 

實現類 ↓

/**
*查詢
**/
 
@Test
    public void Alluser() throws Exception {
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(Resources.getResourceAsStream("mybatis-config.xml"));
        SqlSession sqlSession = sqlSessionFactory.openSession();
        It_user t = sqlSession.getMapper(It_user.class);
        List<t_user> users = t.alluser();
        System.out.println(users);
        sqlSession.close();

    }
/**
*條件查詢
**/

    @Test
    public void AlluserByname() throws Exception {
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(Resources.getResourceAsStream("mybatis-config.xml"));
        SqlSession sqlSession = sqlSessionFactory.openSession();
        It_user t = sqlSession.getMapper(It_user.class);
        t_user user = t.alluserByname("1111");
        System.out.println(user);
        sqlSession.close();
    }

/**
*新增
**/
    @Test
    public void adduser() throws Exception {
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(Resources.getResourceAsStream("mybatis-config.xml"));
        SqlSession sqlSession = sqlSessionFactory.openSession();
        It_user t = sqlSession.getMapper(It_user.class);
        t.adduser(new t_user(String.valueOf(UUID.randomUUID()), "5", "1"));  
        sqlSession.commit();
        sqlSession.close();
    }
/**
*修改
**/
@Test
    public void edituser()throws  Exception{
    SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(Resources.getResourceAsStream("mybatis-config.xml"));
    SqlSession sqlSession = sqlSessionFactory.openSession();
    It_user t = sqlSession.getMapper(It_user.class);
    t.edituser(new t_user("21244f5e-3621-4178-9e60-8e1ec6f9b121","www","eeee"));
    sqlSession.commit();
    sqlSession.close();
}
/**
*刪除
**/
@Test
    public void  deleteuser() throws Exception{
    SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(Resources.getResourceAsStream("mybatis-config.xml"));
    SqlSession sqlSession = sqlSessionFactory.openSession();
    It_user t = sqlSession.getMapper(It_user.class);
    t.deleteuser("21244f5e-3621-4178-9e60-8e1ec6f9b121");
    sqlSession.commit();
    sqlSession.close();
}
 

上面就是 mybatis 的註解 如有不足 歡迎大路大神 指出！！！！！