Mybatis基本操作：增删改查-优快云博客

本文链接：https://blog.youkuaiyun.com/DBAA12138/article/details/111502600

本文介绍了使用Mybatis进行数据操作的基本步骤，包括在接口定义CRUD方法，Mapper.xml文件中编写SQL语句，以及在Test测试类中进行事务提交。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

Mybatis的增删改查

1.接口

在接口中写增、删、改、查方法

    //根据id查询用户
    User getUserById(int id);

    //增加一个用户
    int addUser(User user);

    //修改用户
    int updateUser(User user);

    //删除用户
    int deleteUser(int id);

2.Mapper.xml

直接填写sql语句

 <select id="getUserById" parameterType="int" resultType="com.zzt.pojo.User">
        select * from mybatis.user where id=#{id}
    </select>

<!--对象的属性，可以直接取出来-->
    <insert id="addUser" parameterType="com.zzt.pojo.User" >
        insert into mybatis.user (id,name,pwd) values (#{id},#{name},#{pwd});
    </insert>

    <update id="updateUser" parameterType="com.zzt.pojo.User">
        update mybatis.user set name=#{name},pwd=#{pwd}  where id=#{id} ;
    </update>

    <delete id="deleteUser" parameterType="int">
        delete from mybatis.user where id=#{id};
    </delete>

3. Test测试类

需要提交事务sqlSession.commit();

 @Test
    public void getUserById(){
        SqlSession sqlSession = MybatisUtils.getSqlSession();

        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        User user=mapper.getUserById(1);
        System.out.println(user);
        sqlSession.close();
    }

    //增删改查需要提交事务
    @Test
    public void addUser(){
        SqlSession sqlSession = MybatisUtils.getSqlSession();
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
       mapper.addUser(new User(4,"哦吼","123"));

       //提交事务
        sqlSession.commit();
        sqlSession.close();
    }

    @Test
    public void updateUser(){
        SqlSession sqlSession = MybatisUtils.getSqlSession();
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        mapper.updateUser(new User(4,"吼吼","1234"));

        sqlSession.commit();
        sqlSession.close();
    }

    @Test
    public void deleteUser(){
        SqlSession sqlSession = MybatisUtils.getSqlSession();
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        mapper.deleteUser(4);


        sqlSession.commit();
        sqlSession.close();
    }