使用边上的数组过滤遍历 Arangodb 图

Question

我在 arangodb 中有这个测试图

节点：

[  { "_key": "A", "name": "A", "sector": "a"},
{ "_key": "B", "name": "B", "sector": "a"},
{ "_key": "C1", "name": "C1", "sector": "c"},
{ "_key": "C2", "name": "C2", "sector": "c"},
{ "_key": "C3", "name": "C3", "sector": "c"},
{ "_key": "C4", "name": "C4", "sector": "c"},
{ "_key": "D1", "name": "D1", "sector": "d"},
{ "_key": "D2", "name": "D2", "sector": "d"},
{ "_key": "E1", "name": "E1", "sector": "e"},
{ "_key": "E2", "name": "E2", "sector": "e"},
{ "_key": "E3", "name": "E3", "sector": "e"}]

边：

[{ "_from": "V/A","_to": "V/D1", "cat": [{"c":1,"s":3}] },
{ "_from": "V/A","_to": "V/D2", "cat": [{"c":1,"s":1}] },
{ "_from": "V/B","_to": "V/D2", "cat": [{"c":2,"s":1}] },
{ "_from": "V/D1","_to": "V/E1", "cat": [{"c":1,"s":8}] }, 
{ "_from": "V/D1","_to": "V/E2", "cat": [{"c":1,"s":4}] },
{ "_from": "V/D2","_to": "V/E2", "cat": [{"c":1,"s":3},{"c":2,"s":4}] },
{ "_from": "V/D2","_to": "V/E3", "cat": [{"c":2,"s":4}] },
{ "_from": "V/C1","_to": "V/B", "cat": [{"c":2,"s":5}] },
{ "_from": "V/C1","_to": "V/A", "cat": [{"c":1,"s":6}] },
{ "_from": "V/C2","_to": "V/A", "cat": [{"c":1,"s":2}] },
{ "_from": "V/C3","_to": "V/A", "cat": [{"c":1,"s":1}] },
{ "_from": "V/C4","_to": "V/A", "cat": [{"c":1,"s":1}] },
{ "_from": "V/C4","_to": "V/B", "cat": [{"c":2,"s":2}] } ]

它是更大图的简化部分（几乎一千个节点，几千条边）。请注意，在此示例中，每条边都有一个属性“cat”作为类别对象的数组。实际上，在真实的数据集中，每条边都是一个或多个网络的一部分。有 22 个网络/类别。在这个工作示例中，只有两个，1 和 2。每条边都是一个类别的一部分，除了 D2->E3 是这里唯一的一个作为两个类别的成员。

问题：我必须从给定顶点开始，通过过滤/选择所选类别（真实数据中的网络）及其相关顶点的边来遍历图形。当然，避免循环和重复的顶点或边。

示例：从 B 开始，选择类别 2，我需要返回这个集合： v: [B,D2,E2,E3,C1,C4] 和 e: [{B->D2, D2->E2, D2->E3, C1->B, C4->B]

在 AQL 中，我尝试了各种过滤器：

FOR v, e, p IN 0..3 any "nodes/D2" edges OPTIONS {bfs: true, uniqueVertices: 'global'}
  //Here, the filter for cat 2  ?
return p

没有任何效果（当然，我是 Arango 的新手）。

问题一：如何构造过滤器？

问题 2：如何像上例那样格式化结果？更准确地说（每个数组中对象的顺序无关紧要）：

[
  nodes: [{name:"B",sector:"a"}, {name:"D2",sector:"d"}, {name:"E2",sector:"e"}, ...]
  edges: [{source: "B", target: "D2", s:1}, {source: "D2", target: "E2", s:4}, ...]
]

感谢您的帮助。

Answer 1

1) 为了过滤cat 中的条目"c":2，对于路径上的所有边（p.edges[*]），必须检查@987654326 的c 属性（.c）是否@array (.cat[*]) 包含值[2]。

因此我们在访问子属性数组p.edges[*].cat[*].c时使用IN运算符。

FILTER [2] IN p.edges[*].cat[*].c

2) return 格式也可以通过访问子属性来调整，例如：

return {'nodes':{'name':v.name,'sector':v.sector},'edges':{'source':e._from,'target':e._to, 's': e.cat[*].s}}

调整后的查询是：

FOR v, e, p IN 0..3 any "V/D2" edges
FILTER [2] IN p.edges[*].cat[*].c
return {'nodes':{'name':v.name,'sector':v.sector},'edges':{'source':e._from,'target':e._to, 's': e.cat[*].s}}