如何过滤掉 Neo4J/Cypher 中节点之间的非空路径

Question

My current graph monitors board members at a company through time.

However, I'm only interested in currently employed directors. This can be observed because director nodes connect to company nodes through an employment path which includes an end date (r.to) when the director is no longer employed at the firm. If he is currently employed, there will be no end date(null as per below picture). Therefore, I would like to filter the path not containing an end date. I am not sure if the value is an empty string, a null value, or other types so I've been trying different ways without much success. Thanks for any tips!

Current formula

MATCH (c2:Company)-[r2:MANAGED]-(d:Director)-[r:MANAGED]-(c:Company {ticker:'COMS'})
WHERE r.to Is null
RETURN c,d,c2

Answer 1

Unless the response from the Neo4j browser was edited, it looks like the value of r.to is not null or empty, but the string None . This query will help verify if this is the case:

MATCH (d:Director)-[r:MANAGED]-(c:Company {ticker:'COMS'})
RETURN DISTINCT r.to ORDER by r.to DESC

Absence of the property will show a null in the tabular response. Any other value is a real value of that property. If None shows up, then your query would be

MATCH (c2:Company)-[r2:MANAGED]-(d:Director)-[r:MANAGED]-(c:Company {ticker:'COMS'})
WHERE r.to="None"
RETURN c,d,c2