Mybatis使用注解开发_java mybatis注解开发service-优快云博客

本文链接：https://blog.youkuaiyun.com/qq_52146944/article/details/129903248

文章展示了如何使用MyBatis的注解进行数据库操作，包括通过@Select查询所有用户，@Insert插入用户，@Update删除和修改用户信息。每个操作都在测试方法中进行了演示，并确保事务提交。

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一、使用注解开发

注解在接口实现

    @Select( "select * from user" )
    List<User> SelectAllUser();

需要在核心配置文件中进行绑定接口

<!--    接口绑定-->
    <mappers>
        <mapper class="com.RXJ.mapper.UserMapper"/>
    </mappers>

测试

    @Test
    public void tset(){
        SqlSession sqlSession = MybatisUtils.getSqlSession();
        UserMapper mapper = sqlSession.getMapper( UserMapper.class );
        List<User> users = mapper.SelectAllUser();
        for (User user:users){
            System.out.println(user.toString());
        }
        sqlSession.close();
    }

增加用户

接口

//增加用户
    @Insert( "insert into user(id,name,pd) VALUES(#{id},#{name},#{pd})" )
    int InsertUser(User user);

核心配置文件

<!--    接口绑定-->
    <mappers>
        <mapper class="com.RXJ.mapper.UserMapper"/>
    </mappers>

测试

    @Test
    public void insertUser(){
        SqlSession sqlSession = MybatisUtils.getSqlSession();
        UserMapper mapper = sqlSession.getMapper( UserMapper.class );
        User user = new User( 9, "wei", "180" );
        int i = mapper.InsertUser( user );
        sqlSession.commit();
        if (i>0){
            System.out.println("添加成功");
        }else {
            System.out.println("添加失败");
        }
        sqlSession.close();
    }

删除用户

接口

    //根据id删除用户
    @Update( "delete from user where id=#{id}" )
    int DeleteUser(int id);

核心配置文件

<!--    接口绑定-->
    <mappers>
        <mapper class="com.RXJ.mapper.UserMapper"/>
    </mappers>

测试

    @Test
    public void deleteUser(){
        SqlSession sqlSession = MybatisUtils.getSqlSession();
        UserMapper mapper = sqlSession.getMapper( UserMapper.class );
        int i = mapper.DeleteUser( 9 );
        sqlSession.commit();
        if (i>0){
            System.out.println("删除成功");
        }else {
            System.out.println("删除失败");
        }
        sqlSession.close();
    }

修改用户

接口

    //根据id修改用户
    @Update( "update user set name=#{name},pd=#{pd} where id=#{id}" )
    int updateUser(User user);

核心配置文件

<!--    接口绑定-->
    <mappers>
        <mapper class="com.RXJ.mapper.UserMapper"/>
    </mappers>

测试

    @Test
    public void uptateUser(){
        SqlSession sqlSession = MybatisUtils.getSqlSession();
        UserMapper mapper = sqlSession.getMapper( UserMapper.class );
        User user = new User( 6, "dsa", "369" );
        int i = mapper.updateUser( user );
        sqlSession.commit();
        if (i>0){
            System.out.println("修改成功");
        }else {
            System.out.println("修改失败");
        }
        sqlSession.close();
    }

注意：方法存在多个参数，必须加上@Param("xxx")