SQL Server 图表以获取连接到节点的多个节点类型答案

【问题标题】：SQL Server 图表以获取连接到节点的多个节点类型
【发布时间】：2021-04-24 23:51:25
【问题描述】：

我计划在我的一个项目中使用 SQL Server 2019 图形功能。数据方案如下图所示。

给定用户（ID：2356，名称：Mark），我想检索用户的追随者完成的所有帖子和推文，这些帖子和推文按发布时间或推文时的限制/分页时间排序总体结果。

到目前为止，除了进行 2 个单独的查询和手动处理分页之外，我不知道有更好的方法，如果我们将来除了已发布/推文之外添加另一种新的边缘类型，这将使其效率低下且也很麻烦。

有没有更好的方法来解决 SQL Server 图中的此类用例？

SELECT mainUser.*, followingUser.*, followerPost.*
FROM 
     User mainUser, Follows userFollows, User followingUser, Posted followerPosted, Post followerPost 
WHERE 
     MATCH (mainUser-(userFollows)->followingUser-(followerPosted)->followerPost)
AND
     mainUser.id=2356
ORDER BY
     followerPosted.posted_on desc

SELECT mainUser.*, followingUser.*, followerTweet.*
FROM 
     User mainUser, Follows userFollows, User followingUser, Tweeted tweeted, Tweet followerTweet 
WHERE 
     MATCH (mainUser-(userFollows)->followingUser-(tweeted)->followerTweet)
AND
     mainUser.id=2356
ORDER BY
     tweeted.tweeted_on desc

【问题讨论】：

标签： sql-server graph-databases sql-server-2019 sql-server-graph sql-graph

【解决方案1】：

使用异构边或节点视图。见答案https://stackoverflow.com/a/70055567/3434168。

---- there may be column colisions due to UNION ALL so fix them as you need
---- it doesn't matter which columns you select in your view
---- the MATCH algorithm (probably) uses metadata of the VIEW
CREATE VIEW v_SecondTierEdges AS
  SELECT *, 'Tweeted' AS Type FROM Tweeted
  UNION ALL
  SELECT *, 'Posted' AS Type FROM Posted
GO

CREATE VIEW v_SecondTierNodes AS
  SELECT tweeted_on AS did_that_on, 'Tweet' AS Type FROM Tweet
  UNION ALL
  SELECT posted_on AS did_that_on, 'Post' AS Type FROM Post
GO

SELECT
  mainUser.*, followingUser.*, followerTweet_or_Post.*
FROM 
  User mainUser, Follows userFollows, User followingUser, v_SecondTierEdges tweeted_or_posted, v_SecondTierNodes followerTweet_or_Post 
WHERE 
  MATCH (mainUser-(userFollows)->followingUser-(tweeted_or_posted)->followerTweet_or_Post)
AND
  mainUser.id=2356
ORDER BY
  tweeted_or_posted.did_that_on desc

【讨论】：