MySQL:変相実装ソート関数

MySQL 8.0以前はSQL Serverソート関数が不足していましたが、相を変えてしか実現できませんでした.
関連投稿:https://bbs.csdn.net/topics/392500595?page=1#post-403630664

drop table if exists t;
create table t(
	id int not null AUTO_INCREMENT primary key,
	wd DECIMAL(10,2),
	addTime datetime
);
INSERT t (wd,addTime) values(10,'2018-12-27 03:00');
INSERT t (wd,addTime) values(10,'2018-12-27 03:01');
INSERT t (wd,addTime) values(11,'2018-12-27 03:10');
INSERT t (wd,addTime) values(12,'2018-12-27 03:12');
INSERT t (wd,addTime) values(13,'2018-12-27 03:13');
INSERT t (wd,addTime) values(14,'2018-12-27 03:20');
INSERT t (wd,addTime) values(10,'2018-12-27 04:00');
INSERT t (wd,addTime) values(10,'2018-12-27 05:01');
INSERT t (wd,addTime) values(11,'2018-12-27 06:10');
INSERT t (wd,addTime) values(12,'2018-12-27 07:12');
INSERT t (wd,addTime) values(13,'2018-12-27 08:13');
INSERT t (wd,addTime) values(23,'2018-12-27 09:20');
#        

/*
1.       8       ，8                 ，   16   ，                    ，         
*/
select * from (
select 
(
  SELECT COUNT(*) FROM t t2 WHERE 
  1=1
   AND DATE_FORMAT(t1.addTime,'%Y-%m-%d %H')= DATE_FORMAT(t2.addTime,'%Y-%m-%d %H') 
  AND t1.id >= t2.id
) as rid
,id
,wd
,addTime
from t as t1 where t1.addTime>DATE_ADD(t1.addTime,INTERVAL -8 hour)
) as tt
where rid in (1,6);
/*
+-----+----+-------+---------------------+
| rid | id | wd    | addTime             |
+-----+----+-------+---------------------+
|   1 |  1 | 10.00 | 2018-12-27 03:00:00 |
|   6 |  6 | 14.00 | 2018-12-27 03:20:00 |
|   1 |  7 | 10.00 | 2018-12-27 04:00:00 |
|   1 |  8 | 10.00 | 2018-12-27 05:01:00 |
|   1 |  9 | 11.00 | 2018-12-27 06:10:00 |
|   1 | 10 | 12.00 | 2018-12-27 07:12:00 |
|   1 | 11 | 13.00 | 2018-12-27 08:13:00 |
|   1 | 12 | 23.00 | 2018-12-27 09:20:00 |
+-----+----+-------+---------------------+
*/

/*
2.  8           ，       23 ，     23 ，     23.1 ，     24 ，             、   、     ，              
*/
drop TEMPORARY TABLE if exists tmp;
drop TEMPORARY TABLE if exists tmp2;
CREATE TEMPORARY  TABLE tmp(
	rid int,
	id int,
	wd DECIMAL(10,2),
	addTime datetime,
	timeSeg int
);
CREATE TEMPORARY  TABLE tmp2(
	rid int,
	id int,
	wd DECIMAL(10,2),
	addTime datetime,
	timeSeg int
);

insert into tmp
select * from (
select 
(
  SELECT COUNT(*) FROM t t2 WHERE 
  1=1
  AND DATE_FORMAT(t1.addTime,'%Y-%m-%d %H')= DATE_FORMAT(t2.addTime,'%Y-%m-%d %H') 
  AND t1.id >= t2.id
) as rid
,id
,wd
,addTime
,DATE_FORMAT(t1.addTime,'%Y%m%d%H') as timeSeg
from t as t1 where t1.addTime>DATE_ADD(t1.addTime,INTERVAL -8 hour)
) as tt
;
insert into tmp2
select * from tmp;

select 
id
,wd
,addTime
from (
select a.*,case when a.rid=1 or (b.wd is not null and a.wd!=b.wd) then 1 else 0 end as r from tmp as a 
    left join tmp2 as b on a.timeSeg=b.timeSeg and a.rid=b.rid+1
) as tt
where tt.r=1
order by tt.timeSeg,tt.rid
;
/*
+----+-------+---------------------+
| id | wd    | addTime             |
+----+-------+---------------------+
|  1 | 10.00 | 2018-12-27 03:00:00 |
|  3 | 11.00 | 2018-12-27 03:10:00 |
|  4 | 12.00 | 2018-12-27 03:12:00 |
|  5 | 13.00 | 2018-12-27 03:13:00 |
|  6 | 14.00 | 2018-12-27 03:20:00 |
|  7 | 10.00 | 2018-12-27 04:00:00 |
|  8 | 10.00 | 2018-12-27 05:01:00 |
|  9 | 11.00 | 2018-12-27 06:10:00 |
| 10 | 12.00 | 2018-12-27 07:12:00 |
| 11 | 13.00 | 2018-12-27 08:13:00 |
| 12 | 23.00 | 2018-12-27 09:20:00 |
+----+-------+---------------------+
*/