Question

我正在尝试收集不同的节点路径长度，以及基于路径长度分配变量的目标。节点不在路径中=分离，路径长度为1 =半，路径长度> 1 =梯形。

我有以下密码，但是返回收集的列表时，即使每个部分都能正常工作，也不会返回任何内容。

match (a:Test) where not (a)-[]-() with a, COLLECT(DISTINCT a) as detached  
match (a:Test)-[r]-() with a,detached,count(r) as rels where rels = 1 
match path = (a)-[]->() with detached, COLLECT(DISTINCT NODES(path)) AS semis 
match path = (a)-[:NEIGHBOURING_BUILDING*]-() where length(path) > 1 with detached, semis, COLLECT(DISTINCT NODES(path)) AS terraces 
return detached, semis, terraces

我目前正在使用这个测试网络

create (:Test{id:1}) 
create (:Test{id:2})
create (:Test{id:3})-[:NEIGHBOUR]->(:Test{id:4}) 
create (:Test{id:5})-[:NEIGHBOUR]->(:Test{id:6})<-[:NEIGHBOUR]-(:Test{id:7})
create (:Test{id:8})-[:NEIGHBOUR]->(:Test{id:9})
create (:Test{id:10})-[:NEIGHBOUR]->(:Test{id:11})<-[:NEIGHBOUR]-(:Test{id:12})

如何将每种路径中的节点收集到列表中？

Answer 1

您的查询有些奇怪：

match (a:Test) where not (a)-[]-() with a, COLLECT(DISTINCT a) as detached  
match (a:Test)-[r]-() with a,detached,count(r) as rels where rels = 1

在第一行上，您正在搜索没有任何关系（a）的节点not (a)-[]-()，然后在第二行上，您需要此同一个节点的关系：{{1} }。

所以没有结果是正常的....

在neo4j

1 个答案: