图最短路径..只使用标记边？

Question

在新的 SQL 服务器版本中，有功能 SHORTEST_PATH。我在边缘表中使用属性（或标签）来区分不同类型的连接。

不幸的是，SHORTEST_PATH 函数似乎不允许 where 条件中的任何属性（如果表被标记为路径）

SELECT
       l1.CommonName AS CommonName, 
       STRING_AGG(l2.CommonName, '->') WITHIN GROUP (GRAPH PATH) AS Verbindung,
       LAST_VALUE(l2.CommonName) WITHIN GROUP (GRAPH PATH) AS LastNode
 from           object as l1, 
                connections for path as v,
                object for path as  l2 
    where match(SHORTEST_PATH( l1  (-(v)-> l2)+))
    and l1.CommonName = 'jagdtWurst'
    and v.label= 'hierarchie' <<--- This is not possible .... Error

有没有什么技巧可以做到这一点？

Answer 1

看起来您可以在 from 子句中使用子查询。例如

SELECT
       l1.CommonName AS CommonName, 
       STRING_AGG(l2.CommonName, '->') WITHIN GROUP (GRAPH PATH) AS Verbindung,
       LAST_VALUE(l2.CommonName) WITHIN GROUP (GRAPH PATH) AS LastNode
 from           object as l1, 
                (select * from connections where label = 'hierarchie') for path as v,
                object for path as  l2 
    where match(SHORTEST_PATH( l1  (-(v)-> l2)+))
    and l1.CommonName = 'jagdtWurst'

图最短路径..只使用标记边？

Graph shortest path .. use only labelled edges?

sql

sql-server

tsql

graph-algorithm

sql-server-2019