ArangoDB 3.0中朋友查询的朋友 [英] friends of friend Query in ArangoDB 3.0

问题描述

我想使用 AQL

I want to writing 'friends of friend' traversal using AQL

我有一个名称为:用户的收藏集和一个名称为连接的边缘收藏集.

I have a Collection with Name:User and a edge Collection with name Conatct.

我的联系文档:

我还阅读了这篇文章，在ArangoDb中实现朋友的朋友，但这是使用使用GRAPH_NEIGHBORS()函数的ArangoDB较低版本的函数的帖子.

I also read this article that implement friends of friend in ArangoDb, but that's post Uses functions of lower version of ArangoDB that used GRAPH_NEIGHBORS() function.

在ArnagoDB 3.0(最新版本)中， GRAPH_NEIGHBORS()函数已被删除！

in ArnagoDB 3.0(latest version), GRAPH_NEIGHBORS() function have been removed!

现在，如何在ArnagoDB 3.0中使用Aql实现fof?

now, how can I implement fof using Aql in ArnagoDB 3.0 ?

非常感谢

推荐答案

The graph functions have been removed, because there is the more powerful, flexible and performant native AQL traversal, which was introduced with 2.8, and extended and optimized for version 3.0.

要检索朋友的朋友，需要从有问题的用户处开始遍历，遍历深度为2:

To retrieve friends of friends, a traversal starting at the user in question with a traversal depth = 2 is needed:

LET user = DOCUMENT("User/@9302796301")
LET foaf = (
  FOR v IN 2..2 ANY user Contact
    RETURN v // you might wanna return the name only here
)
RETURN MERGE(user, { foaf } )

已加载_key = @9302796301的用户文档，并将其分配给变量user.它用作最小深度和最大深度= 2的遍历的起始顶点，使用集合Contact的边缘并忽略其方向(ANY；也可以是INBOUND或OUTBOUND).在此示例中，将完全返回friends文档的friends(v)，并使用属性键"foaf"和变量foaf的值将其与user文档合并.

The document for the user with _key = @9302796301 is loaded and assigned to a variable user. It is used as start vertex for a traversal with min and max depth = 2, using the edges of the collection Contact and ignoring their direction (ANY; can also be INBOUND or OUTBOUND). The friends of friends documents are fully returned in this example (v) and merged with the user document, using the attribute key "foaf" and the value of the variable foaf.

这只是一个简单的示例，它如何遍历图形以及如何构造结果集.当然，还有更多选择.

This is just one simple example how to traverse graphs and how to construct result sets. There are many more options of course.

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