SQL 服務器圖形數據庫 - 使用多種邊類型的最短路徑

Question

我已經對 SQL Server GraphDB 進行了研究，但是到目前為止我發現的所有人為示例都只使用了一個邊表。 例如，它總是Person-friend_of->Person 。 就我而言，我在我們的數據中心創建了一個已部署軟件組件的圖表，並且存在不同的邊緣/關系。 諸如Application-connects_to->SqlDatabase和Server-hosts->Application 。

我想編寫一個查詢，它將向我顯示任意兩個節點之間的最短路徑，而不管使用的邊緣如何。 我想如果我使用的是 Neo4j，我會把MATCH寫成這樣：

Server-*->SqlDatabase注意星號。

在 SQL 服務器中是否有慣用的方法來執行此操作？

Answer 1

自 SQL Server 2019 起，您可以使用派生表或視圖完全做到這一點。 我找不到任何有關此功能的官方文檔，但我在有關材料清單的視頻中發現了一個小注釋。

編輯：他們在該視頻中有一些鏈接： Github 示例

關鍵是您使用多個EDGE （或NODE ）表的UNION ALL來充當MATCH運算符中的一個EDGE （或NODE ）表。

• 您可以使用SUBSELECT
• 你不能使用公用表表達式（雖然我沒有特別努力，但我無法讓它工作）
• 您可以使用視圖

還有一個例子：

BEGIN TRANSACTION; --if you execute code found on internet without any scrutiny and have "people" table in your database
GO

  DROP TABLE IF EXISTS people, knows, killed, likes;

  CREATE TABLE people (Name VARCHAR(100)) AS NODE;
  CREATE TABLE knows AS EDGE;
  CREATE TABLE killed AS EDGE;
  CREATE TABLE likes AS EDGE;

  INSERT INTO people
    (Name)
  VALUES
    ('A'),
    ('B'),
    ('C'),
    ('D'),
    ('E')

  INSERT INTO knows
    ($from_id, $to_id)
  SELECT
    knows.$node_id, known.$node_id
  FROM
    people AS knows,
    people AS known
  WHERE
    knows.Name = 'A' AND known.Name = 'B';

  INSERT INTO killed
    ($from_id, $to_id)
  SELECT
    killed.$node_id, victim.$node_id
  FROM
    people AS killed,
    people AS victim
  WHERE
    (killed.Name = 'A' AND victim.Name = 'C')
    OR (killed.Name = 'C' AND victim.Name = 'E');

  INSERT INTO likes
    ($from_id, $to_id)
  SELECT
    likes.$node_id, liked.$node_id
  FROM
    people AS likes,
    people AS liked
  WHERE
    likes.Name = 'A' AND liked.Name = 'D';

  SELECT
    P1.Name AS First_in_chain,
    LAST_VALUE(P2.Name) WITHIN GROUP (GRAPH PATH) AS Last_in_chain
  FROM
    people AS P1,
    people FOR PATH AS P2,
    ------------------------------------------------------------------
    ---------this is a compound of edges
    (
      SELECT * FROM knows
      UNION ALL
      SELECT * FROM killed
      UNION ALL
      SELECT * FROM likes
    ) FOR PATH AS RELATION
    ------------------------------------------------------------------
  WHERE
    MATCH(
      SHORTEST_PATH(
        P1(-(RELATION)->P2)+
      )
    )
    AND P1.NAME = 'A'
  OPTION(RECOMPILE);

  DROP TABLE IF EXISTS people, knows, killed, likes;

GO
  IF @@TRANCOUNT > 0
    ROLLBACK TRANSACTION