Neo4j Cypher查询：长度可变的路径关系的返回类型

用户， 我尝试接收所有路径（例如，长度<3），打印节点标题，还打印关系类型

使用：

MATCH (p0:Page {title:'New Zealand'}), (p1:Page {title:'Kiwi'}), p = (p0)-[r*..2]-(p1)
RETURN p AS path

打印路径，但关系表示为{}

当我使用*.2时

`RETURN p,type(r)'

不工作（类型不匹配：预期关系，但为集合）

我可以使用以下解决方法：

MATCH
  (p0:Page {title:'New Zealand'}),
  (p1:Page {title:'Kiwi'}),
  p = (p0)-[r]-(p3)-[r1]-(p1)
RETURN p0,type(r),p3,type(r1)

但是随着pathlength的增加，我会对每个pathlength执行一个查询

我试过：

MATCH
  (p0:Page {title:'New Zealand'}),
  (p1:Page {title:'Kiwi'}),
  p = (p0)-[r*..2]-(p1) FOREACH(r in p | RETURN p,p0,type(r),p1)

->应为集合，但为路径

有人有暗示吗

Neo4j接口的JSON输出（代码段）附加信息：

    {
  "results": [
    {
      "columns": [
        "p",
        "rels(p)",
        "nodes(p)"
      ],
      "data": [
        {
          "row": [
            [
              {
                "title": "New Zealand"
              },
              {},
              {
                "title": "Category:Birds of New Zealand"
              },
              {},
              {
                "title": "Kiwi"
              }
            ],
            [
              {},
              {}
            ],
            [
              {
                "title": "New Zealand"
              },
              {
                "title": "Category:Birds of New Zealand"
              },
              {
                "title": "Kiwi"
              }
            ]
          ],
          "graph": {
            "nodes": [
              {
                "id": "11120",
                "labels": [
                  "Page"
                ],
                "properties": {
                  "title": "Kiwi"
                }
              },
              {
                "id": "1942858",
                "labels": [
                  "Page"
                ],
                "properties": {
                  "title": "New Zealand"
                }
              },
              {
                "id": "11994493",
                "labels": [
                  "Category"
                ],
                "properties": {
                  "title": "Category:Birds of New Zealand"
                }
              }
            ],
            "relationships": [
              {
                "id": "1070940",
                "type": "To_Category",
                "startNode": "11120",
                "endNode": "11994493",
                "properties": {}
              },

---

使用

rels

功能是否有帮助

MATCH (p0:Page {title:'New Zealand'}), (p1:Page {title:'Kiwi'}), p = (p0)-[r*..2]-(p1)
RETURN p, rels(p), nodes(p)

---

您可以简单地使用

extract

来提取路径中的关系类型

基于上的简单电影图：

您的查询将是：

MATCH (p0:Page {title:'New Zealand'}), (p1:Page {title:'Kiwi'}), 
p=(p0)-[r*..2]-(p1)
RETURN p, extract (rel in rels(p) | type(rel) ) as types

这将返回以下类型的集合：

[爱，知道，知道]

所以你可以有重复的。如果需要消除重复，请使用“展开”和“区分”：

MATCH (p0:Page {title:'New Zealand'}), (p1:Page {title:'Kiwi'}), 
p=(p0)-[r*..2]-(p1)
WITH p, extract (rel in rels(p) | type(rel) ) as types
UNWIND types as t
RETURN p, collect(distinct t) as types

更新

我对最后一个不太满意，所以这里有一个更简单的方法：

MATCH (p0:Page {title:'New Zealand'}), (p1:Page {title:'Kiwi'}), 
p=(p0)-[r*..2]-(p1)
UNWIND rels(p) as rel
RETURN p, collect(distinct type(rel)) as types

---

谢谢你的快速回复。不幸的是，它具有相同的效果：rels（p）[（空），（空）]；列：[p，rels（p），nodes（p）]当前行0:[[{title=newzealand}，{}，{title=Category:Birds of newzealand}，{}，{}，{title=Kiwi}]，{}，{title=newzealand}，{title=Category:Birds of newzealand}，{title=Kiwi}]。也许我在构建图表时做错了什么（？）

MATCH (p0:Page {title:'New Zealand'}), (p1:Page {title:'Kiwi'}), 
p=(p0)-[r*..2]-(p1)
UNWIND rels(p) as rel
RETURN p, collect(distinct type(rel)) as types