mybatis 注解式开发

  

MyBatis的注解，主要是用于替换映射文件。映射文件中无非存放在增删改查的sql映射标签。所以，MyBatis注解，就是要替换映射文件中的SQL标签。
MyBatis官方文档中指出，若要真正想发挥MyBatis功能，还是要用映射文件。所以官方并不建议使用MyBatis注解式开发。 

 

 

MyBatis的注解主要是在接口方法的的上面的  注意的是注解括号后面不需要打分号。

接口类   ↓

/**
*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);
/**
*删除
**/
@Delete("DELETE  FROM t_user WHERE `uid` = #{uid}")
public void  deleteuser(String uid);
/**
*条件查询
**/
@Select(" select * from t_user where uname=#{uname}")
public  t_user alluserByname(String uname);
/**
*查询所有
**/
@Select("select * from t_user")
public List<t_user> alluser();

实现类 ↓

/**
*查询
**/

@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();

    }
/**
*条件查询
**/

    @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();
}
/**
*删除
**/
@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 的注解 如有不足 欢迎大路大神 指出！！！！！