MyBatis 字段映射的解决方案

public class UserInfo {
    private Integer id;
    private String username;
    private String password;
    private Integer age;
    private String gender;
    private String phone;
    private Integer deleteFlag;   // 数据库字段 delete_flag
    private Date createTime;      // 数据库字段 create_time
    private Date updateTime;      // 数据库字段 update_time
    // getter / setter 省略
}

@Mapper
public interface UserInfoMapper {
    @Results({
        @Result(column = "delete_flag", property = "deleteFlag"),
        @Result(column = "create_time", property = "createTime"),
        @Result(column = "update_time", property = "updateTime")
    })
    @Select("select * from user_info")
    List<UserInfo> selectAll();
    // 另一个查询方法，需要重复写一遍 @Results
    @Results({
        @Result(column = "delete_flag", property = "deleteFlag"),
        @Result(column = "create_time", property = "createTime"),
        @Result(column = "update_time", property = "updateTime")
    })
    @Select("select * from user_info where id = #{id}")
    UserInfo selectById(Integer id);
}

@Mapper
public interface UserInfoMapper {
    @Results(id = "BaseMap", value = {
        @Result(column = "delete_flag", property = "deleteFlag"),
        @Result(column = "create_time", property = "createTime"),
        @Result(column = "update_time", property = "updateTime")
    })
    @Select("select * from user_info")
    List<UserInfo> selectAll();
    // 直接引用上面定义的 BaseMap，无需重复写 @Results
    @ResultMap(value = "BaseMap")
    @Select("select * from user_info where id = #{id}")
    UserInfo selectById(Integer id);
    // 再多一个方法也能复用
    @ResultMap(value = "BaseMap")
    @Select("select * from user_info where username = #{username}")
    UserInfo selectByUsername(String username);
}

# application.yml
mybatis:
  configuration:
    map-underscore-to-camel-case: true # 配置驼峰自动转换

@Mapper
public interface UserInfoMapper {
    @Select("select * from user_info")
    List<UserInfo> selectAll();
    @Select("select * from user_info where id = #{id}")
    UserInfo selectById(Integer id);
    @Select("select * from user_info where username = #{username}")
    UserInfo selectByUsername(String username);
}