一、数据库建表

 二、entity目录下创建user实体类

三、dao目录下创建userMapper映射接口 

@Mapper
public interface UserMapper {User selectById(int id);User selectByName(String username);User selectByEmail(String email);int insertUser(User user);int updateStatus(int id, int status);int updateHeader(int id, String headerUrl);int updatePassword(int id, String password);
}

四、创建user-mapper映射xml文件

xml文件的格式可以在mybatis官网找到，直接复制进文件就行。

username, password, salt, email, type, status, activation_code, header_url, create_timeid, username, password, salt, email, type, status, activation_code, header_url, create_timeselect from userwhere id = #{id}select from userwhere username = #{username}select from userwhere email = #{email}insert into user ()values(#{username}, #{password}, #{salt}, #{email}, #{type}, #{status}, #{activationCode}, #{headerUrl}, #{createTime})update user set status = #{status} where id = #{id}update user set header_url = #{headerUrl} where id = #{id}update user set password = #{password} where id = #{id}

五、测试从数据库中查找

@Test
public void testSelectUser() {User user = userMapper.selectById(101);System.out.println(user);user = userMapper.selectByName("liubei");System.out.println(user);user = userMapper.selectByEmail("nowcoder101@sina.com");System.out.println(user);
}