圖最短路徑..僅使用標記的邊？

Question

隨着新的 SQL 服務器版本有 function SHORTEST_PATH 。 我使用邊緣表中的屬性（或標簽）來區分不同類型的連接。

不幸的是， SHORTEST_PATH function 似乎不允許 where 條件中的任何屬性（如果表被標記為路徑）

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

無論如何，如何做到這一點沒有訣竅嗎？

Answer 1

看起來您可以在from子句中使用子查詢。 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'