mybatis-mp：这是一款你没见过的好用的ORM框架，值得你拥有！不信，可以试试看！

https://gitee.com/mybatis-mp 

@Data
@ResultEntity(SysRole.class)
public class OneToManyVo {

    private Integer id;

    private String name;

    private LocalDateTime createTime;

    @ResultField(value = "otherName")
    private String asName;

    @NestedResultEntity(target = SysUser.class)
    private List<SysUser> sysUserList;
}

查询

List<OneToManyVo> list = QueryChain.of(sysRoleMapper)
                    .select(SysUser.class)
                    .selectWithFun(SysUser::getUserName, c -> c.as(OneToManyVo::getAsName))
                    .select(SysRole.class)
                    .from(SysRole.class)
                    .join(SysRole.class, SysUser.class, on -> on.eq(SysUser::getRole_id, SysRole::getId))
                    .returnType(OneToManyVo.class)
                    .list();

这是中度复杂的的查询，更多请前往官方文档查看： mybatis-mp: 基于mybatis扩展一款半ORM框架，拥有丰富的api