public interface UserMapper {
    //查询全部用户
    List<User> findAll();
    //根据ID查找
    User getUserId(int id);
    //添加用户
    int addUser(User user);
    //更新用户
    int updateUser(User user);
    //删除用户
    int deleteUser(int id);
}

<mapper namespace="mapper.UserMapper">
    <!--配置查询所有-->
    <!--id对应的是dao层的方法名-->
    <select id="findAll" resultType="domain.User">
        select * from user;
    </select>
    <!--根据id的查询-->
    <select id="getUserId" resultType="domain.User" parameterType="int">
        select * from mybatis_study.user where id= #{id};
    </select>
    <!--添加操作-->
    <insert id="addUser" parameterType="domain.User">
        insert into user (id,username,sex,address) values (#{id},#{username},#{sex},#{address});
    </insert>
    <!--更新操作-->
    <update id="updateUser" parameterType="domain.User">
        update user set username=#{username},sex=#{sex},address=#{address} where id = #{id};
    </update>
    <!--删除操作-->
    <delete id="deleteUser" parameterType="int">
        delete from user where id = #{id}
    </delete>
</mapper>

//查询所有
    @Test
    public void TestList(){
        SqlSession session = MybatisUtil.getSqlSession();
        UserMapper userMapper = session.getMapper(UserMapper.class);
        List<User> list = userMapper.findAll();
        for (User user : list) {
            System.out.println(user);
        }
        //释放资源
        session.close();
    }
    //根据ID查询
    @Test
    public void getUserId(){
        SqlSession session = MybatisUtil.getSqlSession();
        UserMapper mapper = session.getMapper(UserMapper.class);
        User userId = mapper.getUserId(41);
        System.out.println(userId);
        session.close();
    }
    //添加操作,增删改都需要提交事务
    @Test
    public void addUser(){
        SqlSession session = MybatisUtil.getSqlSession();
        UserMapper mapper = session.getMapper(UserMapper.class);
        mapper.addUser(new User(3, "小哈", "男", "新乡市"));
        //提交事务
        session.commit();
        session.close();
    }
    //更新操作
    @Test
    public void updateUser(){
        SqlSession session = MybatisUtil.getSqlSession();
        UserMapper mapper = session.getMapper(UserMapper.class);
        mapper.updateUser(new User(3,"小何","女","河南省"));
        //提交事务
        session.commit();
        session.close();
    }
    //删除操作
    @Test
    public void deleteUser(){
        SqlSession session = MybatisUtil.getSqlSession();
        UserMapper mapper = session.getMapper(UserMapper.class);
        mapper.deleteUser(3);
        session.commit();
        session.close();
    }

<!--对象中的属性可以直接取出来，传递map的key-->
    <insert id="addUserMap" parameterType="Map">
        insert into user (id,username) values (#{uid},#{userName})
    </insert>

//使用map来操作
    @Test
    public void addUserMap(){
        SqlSession session = MybatisUtil.getSqlSession();
        UserMapper mapper = session.getMapper(UserMapper.class);
        Map<String,Object> map = new HashMap<String,Object>();
        //key值对应的sql语句中传入的值
        map.put("uid",3);
        map.put("userName","小张");
        mapper.addUserMap(map);
        session.commit();
        session.close();
    }

//模糊查询
    List<User> getUserLike(String username);

<!--模糊查询-->
    <select id="getUserLike" resultType="domain.User">
        select * from user where username like #{username}
    </select>

//模糊查询
    @Test
    public void getUserLike(){
        SqlSession session = MybatisUtil.getSqlSession();
        UserMapper mapper = session.getMapper(UserMapper.class);
        List<User> userLike = mapper.getUserLike("%张%");
        for (User user : userLike) {
            System.out.println(user);
        }
        session.commit();
        session.close();
    }