使用 Neo4j 中的标签列表遍历图形

Question

我有这张图：

CREATE (a:Class {brickClass: 'Building',id:"building1"})
CREATE (b:Class {brickClass: 'Air Handler Unit', id:"ahu1"})
CREATE (c:Class {brickClass: 'Cooling System', id:"cools1"})
CREATE (d:Class {brickClass: 'Heat Exchanger', id:"heatex1"})
CREATE (e:Class {brickClass: 'Heat Exchanger', id:"heatex2"})
CREATE (f:Class {brickClass: 'Heat Exchanger', id:"heatex3"})
CREATE (g:Class {brickClass: 'Pump', id:"pump1"})
CREATE (h:Class {brickClass: 'Pump', id:"pump2"})
CREATE (i:Class {brickClass: 'Pump', id:"pump3"})
CREATE (a)-[r:has_equipment]->(b)
CREATE (a)-[s:has_equipment]->(c)
CREATE (b)-[t:has_equipment]->(d)
CREATE (b)-[u:has_equipment]->(e)
CREATE (c)-[w:has_equipment]->(f)
CREATE (d)-[v:has_equipment]->(g)
CREATE (e)-[x:has_equipment]->(h)
CREATE (f)-[y:has_equipment]->(i)

我想归还热交换器下的所有泵，热交换器又在空气处理单元下，在建筑物下。所以输入是这条路径：

["Building","Air Handler Unit","Heat Exchanger","Pump"]

我试图对此进行编码，结果是这段代码：

WITH ["Building","Air Handler Unit","Heat Exchanger","Pump"] AS labels
UNWIND range(0, size(labels)-1) AS i
WITH labels[i] AS label1, labels[i+1] AS label2, i, labels
match (n:Class{brickClass:label1})-[*..]->(node2:Class{brickClass:label2})
WHERE i + 1 = size(labels) - 1
RETURN node2.id

此代码不返回我想要的。此代码返回所有泵。但我希望它只返回 pump1 和 pump2。我怎样才能改变代码来做到这一点？标签列表可以有不同的长度和标签，所以我不能做任何硬编码。

Answer 1

您可以像这样简单地指定整个路径：

MATCH (c:Class{brickClass: 'Pump'})<-[]-(:Class{brickClass: 'Heat Exchanger'})<-[]-(:Class{brickClass: 'Air Handler Unit'})<-[]-(:Class{brickClass: 'Building'})
RETURN c.id