如何对同一 table 中的两个 GUID 字段按时间顺序排序？
How do I sort into chronological order of two GUID fields from same table?
问题
我有一个带有两个 GUID 字段的 table，其中一个指示哪个 GUID（SuperiorGUID）优于该行（ObjectGUID）。此 table 存在于 MySQL 5.7 数据库中。我需要按这两个字段的菊花链对 table 中的行进行排序。
如何在最新版本为 SuperiorGUID = 'ffffffff-ffff-ffff-ffff-ffffffffffff' 的情况下按顺序排列 ObjectGUID？
Table VersionTracking vt
ObjectGUID
SuperiorGUID
15c9cc74-7653-4000-a3a7-8ab7efe5f5f4
6797d1f2-b81c-4db9-8a8b-ce3e9afc96f7
2bb02d4b-a444-11eb-8b72-000c29e16cdc
d72fe08a-2034-4615-96b9-a4e3e2d496a1
6797d1f2-b81c-4db9-8a8b-ce3e9afc96f7
ab921294-6d3a-4cb3-8adb-3f0f76fa8635
a637d8be-8840-4053-9082-9e86b141ddca
ffffffff-ffff-ffff-ffff-ffffffffffff
ab921294-6d3a-4cb3-8adb-3f0f76fa8635
a637d8be-8840-4053-9082-9e86b141ddca
d72fe08a-2034-4615-96b9-a4e3e2d496a1
15c9cc74-7653-4000-a3a7-8ab7efe5f5f4
期望输出
ObjectGUID
SuperiorGUID
a637d8be-8840-4053-9082-9e86b141ddca
ffffffff-ffff-ffff-ffff-ffffffffffff
ab921294-6d3a-4cb3-8adb-3f0f76fa8635
a637d8be-8840-4053-9082-9e86b141ddca
6797d1f2-b81c-4db9-8a8b-ce3e9afc96f7
ab921294-6d3a-4cb3-8adb-3f0f76fa8635
15c9cc74-7653-4000-a3a7-8ab7efe5f5f4
6797d1f2-b81c-4db9-8a8b-ce3e9afc96f7
d72fe08a-2034-4615-96b9-a4e3e2d496a1
15c9cc74-7653-4000-a3a7-8ab7efe5f5f4
2bb02d4b-a444-11eb-8b72-000c29e16cdc
d72fe08a-2034-4615-96b9-a4e3e2d496a1
演示最大链长度为 3，我会这样做：
select
elt(d, vt1.ObjectGUID, vt2.ObjectGUID, vt3.ObjectGUID) ObjectGUID,
elt(d, vt1.SuperiorGUID, vt2.SuperiorGUID, vt3.SuperiorGUID) SuperiorGUID
from (
select 1 d union all select 2 union all select 3
) depths
cross join vt vt1
left join vt vt2 on d>=2 and vt2.SuperiorGUID=vt1.ObjectGUID
left join vt vt3 on d>=3 and vt3.SuperiorGUID=vt2.ObjectGUID
where vt1.SuperiorGUID='ffffffff-ffff-ffff-ffff-ffffffffffff'
order by d
这对我来说似乎比基于子查询的解决方案更直接，但受到 61 个连接表的限制。
递归查询解决方案，MySQL8.0可用：
WITH RECURSIVE cte AS (
SELECT ObjectGUID, SuperiorGuid, 1 AS level
FROM MyTable
WHERE SuperiorGuid = 'ffffffff-ffff-ffff-ffff-ffffffffffff'
UNION ALL
SELECT m.ObjectGuid, m.SuperiorGuid, cte.level+1
FROM MyTable AS m JOIN cte ON m.SuperiorGuid = cte.ObjectGUID
)
SELECT ObjectGUID, SuperiorGUID FROM cte ORDER BY level;
问题
我有一个带有两个 GUID 字段的 table，其中一个指示哪个 GUID（SuperiorGUID）优于该行（ObjectGUID）。此 table 存在于 MySQL 5.7 数据库中。我需要按这两个字段的菊花链对 table 中的行进行排序。
如何在最新版本为 SuperiorGUID = 'ffffffff-ffff-ffff-ffff-ffffffffffff' 的情况下按顺序排列 ObjectGUID？
Table VersionTracking vt
| ObjectGUID | SuperiorGUID |
|---|---|
| 15c9cc74-7653-4000-a3a7-8ab7efe5f5f4 | 6797d1f2-b81c-4db9-8a8b-ce3e9afc96f7 |
| 2bb02d4b-a444-11eb-8b72-000c29e16cdc | d72fe08a-2034-4615-96b9-a4e3e2d496a1 |
| 6797d1f2-b81c-4db9-8a8b-ce3e9afc96f7 | ab921294-6d3a-4cb3-8adb-3f0f76fa8635 |
| a637d8be-8840-4053-9082-9e86b141ddca | ffffffff-ffff-ffff-ffff-ffffffffffff |
| ab921294-6d3a-4cb3-8adb-3f0f76fa8635 | a637d8be-8840-4053-9082-9e86b141ddca |
| d72fe08a-2034-4615-96b9-a4e3e2d496a1 | 15c9cc74-7653-4000-a3a7-8ab7efe5f5f4 |
期望输出
| ObjectGUID | SuperiorGUID |
|---|---|
| a637d8be-8840-4053-9082-9e86b141ddca | ffffffff-ffff-ffff-ffff-ffffffffffff |
| ab921294-6d3a-4cb3-8adb-3f0f76fa8635 | a637d8be-8840-4053-9082-9e86b141ddca |
| 6797d1f2-b81c-4db9-8a8b-ce3e9afc96f7 | ab921294-6d3a-4cb3-8adb-3f0f76fa8635 |
| 15c9cc74-7653-4000-a3a7-8ab7efe5f5f4 | 6797d1f2-b81c-4db9-8a8b-ce3e9afc96f7 |
| d72fe08a-2034-4615-96b9-a4e3e2d496a1 | 15c9cc74-7653-4000-a3a7-8ab7efe5f5f4 |
| 2bb02d4b-a444-11eb-8b72-000c29e16cdc | d72fe08a-2034-4615-96b9-a4e3e2d496a1 |
演示最大链长度为 3，我会这样做：
select
elt(d, vt1.ObjectGUID, vt2.ObjectGUID, vt3.ObjectGUID) ObjectGUID,
elt(d, vt1.SuperiorGUID, vt2.SuperiorGUID, vt3.SuperiorGUID) SuperiorGUID
from (
select 1 d union all select 2 union all select 3
) depths
cross join vt vt1
left join vt vt2 on d>=2 and vt2.SuperiorGUID=vt1.ObjectGUID
left join vt vt3 on d>=3 and vt3.SuperiorGUID=vt2.ObjectGUID
where vt1.SuperiorGUID='ffffffff-ffff-ffff-ffff-ffffffffffff'
order by d
这对我来说似乎比基于子查询的解决方案更直接，但受到 61 个连接表的限制。
递归查询解决方案，MySQL8.0可用：
WITH RECURSIVE cte AS (
SELECT ObjectGUID, SuperiorGuid, 1 AS level
FROM MyTable
WHERE SuperiorGuid = 'ffffffff-ffff-ffff-ffff-ffffffffffff'
UNION ALL
SELECT m.ObjectGuid, m.SuperiorGuid, cte.level+1
FROM MyTable AS m JOIN cte ON m.SuperiorGuid = cte.ObjectGUID
)
SELECT ObjectGUID, SuperiorGUID FROM cte ORDER BY level;