Question

NEO4J 1.9.x

我正在尝试创建一个检索用户帖子的查询语句。目前我只提取通过友情关系创建的帖子。这很好，但是，我想插入请求者创建的帖子。结果是包含作者帖子以及朋友帖子的Feed。在我的生活中，我不能弄清楚如何去做。

START 
    requestor=node:node_auto_index(UID = '19')
MATCH 
    (requestor)-[:Are_Connected]-(friends)-[:Wrote|Shared]-(post)<-[?:Included_With]-(link)
WHERE 
    post.type! = "Post"
RETURN DISTINCT post, link
ORDER BY post.createdzulu DESC

这正是我需要的东西。试试这个...

START 
    requestor=node:node_auto_index(UID = '19')
MATCH 
    (requestor)-[:Are_Connected]-(friends)-[:Wrote|Shared]-(post)<-[?:Included_With]-(link),
    (requestor)-[:Wrote|Shared]-(post)<-[?:Included_With]-(link)
WHERE 
    post.type! = "Post"
RETURN DISTINCT post, link
ORDER BY post.createdzulu DESC

...不返回任何内容，因为此处的匹配是 AND 而不是 OR

我可以通过执行两个查询并合并结果来以编程方式解决此问题，但这对我的口味来说有点过于苛刻。任何帮助将不胜感激。

Answer 1

你可以使用union

START 
    requestor=node:node_auto_index(UID = '19')
MATCH 
    (requestor)-[:Are_Connected]-(friends)-[:Wrote|Shared]-(post)<-[?:Included_With]-(link)
WHERE 
    post.type! = "Post"
RETURN DISTINCT post, link
ORDER BY post.createdzulu DESC
UNION
MATCH
    (requestor)-[:Wrote|Shared]-(post)<-[?:Included_With]-(link)
WHERE 
    post.type! = "Post"
RETURN DISTINCT post, link
ORDER BY post.createdzulu DESC

Answer 2

据我所知和理解，我认为我有一个与我想做的查询类似的问题。我记得最后一件事就是在两场比赛中都使用了where子句。

START 
    requestor=node:node_auto_index(UID = '19')
WHERE 
    ((requestor)-[:Are_Connected]-(friends)-[:Wrote|Shared]-(post)<-[?:Included_With]-(link)
    OR
    (requestor)-[:Wrote|Shared]-(post)<-[?:Included_With]-(link))
AND WHERE 
    post.type! = "Post"
RETURN DISTINCT post, link
ORDER BY post.createdzulu DESC

我不确定效率，因为在我使用neo4j的测试中，匹配子句通常更快，但你可以试试。

希望有所帮助

Neo4j 1.9：多重匹配或合并

2 个答案: