匹配两个或多个关系（AND）关系的Neo4j节点的表达

Question

我需要一个表达式来匹配满足两个或更多关系的Neo4j节点。我尝试了以下方法：

MATCH (p:pm{name: 'G1'})-[:HAS]->(e:en{name:'GREY1'})-[:WITH]-(a:RED2),
      (p:pm{name: 'G1'})-[:HAS]->(e:en{name:'GREY2'})-[:WITH]-(a:RED2) 
RETURN a

MATCH (p)--(a)--(e) 
WHERE (p:pm{name: 'G1'})-[:HAS]->(e:en{name:'GREY1'})-[:WITH]-(a:RED2) AND
      (p:pm{name: 'G1'})-[:HAS]->(e:en{name:'GREY2'})-[:WITH]-(a:RED2) 
RETURN a

但是我没有返回任何节点，两个match语句都是单独工作的

[如何致电RED2]

Answer 1

问题是您将相同的变量名称e用于不同的节点。试试这个：

MATCH (p:pm{name: 'G1'})-[:HAS]->(e1:en{name:'GREY1'})-[:WITH]-(a:RED2),
      (p:pm{name: 'G1'})-[:HAS]->(e2:en{name:'GREY2'})-[:WITH]-(a:RED2) 
RETURN a

Answer 2

此查询将为您提供以下响应：

MATCH (p:pm{name: 'G1'})-[:HAS]->(e1:en{name:'GREY1'})-[:WITH]-(a:RED2),
      (p:pm{name: 'G1'})-[:HAS]->(e2:en{name:'GREY2'})-[:WITH]-(a:RED2) 
      RETURN a

这是流程：

通过关系HAS从G1节点到GREY1和GREY2，现在您已经到达那些节点，任何与GREY1和GREY2具有WITH关系的RED2节点都将作为返回。

如果您需要保留G1与RED2的关系，则还必须在查询中包括TO关系。

所以您的查询应该是：

  `MATCH (p:pm{name: 'G1'})-[:HAS]->(e1:en{name:'GREY1'})-[:WITH]-(a:RED2),
  (p:pm{name: 'G1'})-[:HAS]->(e2:en{name:'GREY2'})-[:WITH]-(a:RED2), 
  (P:pm{name:'G1'})-[:TO]->(a:RED2)
  RETURN a`