Neo4j返回节点通过给定标签和属性的关系连接

Question

I am trying to find the nodes connected that are connected by the relationships having a given label and a given attribute.

For example I want to find all nodes connected by a relationship Edge having as myID 123

I started from this query that returns the data on the relationships.

MATCH ()-[r:Edge{myID: "123"}]->()RETURN r;

Counting these relationships with

MATCH ()-[r:Edge{myID: "123"}]->()RETURN count(r)

I get 45.

I then created the following:

MATCH (a)-[r:Edge{myID: "123"}]->(b)RETURN a,b,r LIMIT 25

However this is not working: it seems to return much more nodes than expected: first of all LIMIT is not limiting and hence the subgraph becomes very big and difficult to analyze but it seems that it is returning even nodes-relationship with a myID property different than 123 , for sure more than 45.

How can I do that?

EDIT

Take as example the following graph:

//create 2 nodes
CREATE (: myNode{NID : 1});
CREATE (: myNode{NID : 1});
//create 2 relationships:
MATCH (n1:myNode{NID:1})
MATCH (n2:myNode{NID:1})
MErGE(n1)-[r:Edge{myID:2}]->(n2);

MATCH (n1:myNode{NID:1})
MATCH (n2:myNode{NID:2})
MErGE(n1)-[r:Edge{myID:2}]->(n2);

The problem can be seen trying the following queries that will return both the edges:

MATCH p=(a)-[r:Edge{myID : 1}]->(b) return p limit 1;

MATCH (a)-[r:Edge{myID : 1}]->(b) return a,r,b limit 1;

Answer 1

If you are using the neo4j browser to enter queries and visualize the results, you should be aware of the browser's "Connect result nodes" option. When that option is enabled, the browser automatically queries for (and displays) the relationships between the nodes returned by a Cypher query. (And note that a returned relationship references 2 nodes.)

You can enable/disable the "Connect result nodes" option by clicking the gear icon on the left side of the browser window, scrolling to the bottom of the Browser Settings panel, and checkmarking/uncheckmarking the "Connect result nodes" box.

Answer 2

Neo4J Browser by default tries to expand the nodes that are displayed in the view when nodes are returned.

Can you please try

MATCH p=(a)-[r:Edge{myID: "123"}]->(b) return p limit 25.

Neo4J Browser should not try to expand the nodes now.