How to nest a query with Neo4j?

Question

I am trying to do a sort of nested Neo4j query in Java, which first labels a subset of nodes and then tries to match certain patterns among them. More specifically it is like combining 2 queries of this type:

1 - MATCH (n)-[r:RELATIONSHIP*1..3]->(m) set m:LABEL

2 - MATCH (p:LABEL)-[r2:RELATIONSHIP]->(q:OTHERLABEL) where r2.time<100 return p,r2,q

Is there a way I can merge these two query in only one using the Java function engine.execute() ?

Answer 1

'p' in query #2 will, in general, correspond to a superset of 'm' in query #1. If that is your intention, then the following should work. Notice that the 2 MATCH statements have no common variables, but a WITH is required by the Cypher syntax, so I arbitrarily picked the variable 'm' to pass to the second MATCH (even though it will be ignored).

MATCH (n)-[r:RELATIONSHIP*1..3]->(m)
SET m:LABEL
WITH m
MATCH (p:LABEL)-[r2:RELATIONSHIP]->(q:OTHERLABEL)
WHERE r2.time<100
RETURN p,r2,q;

If you intend 'm' and ''p' to be the exactly the same, then just replace '(p:LABEL)' with '(m)':

MATCH (n)-[r:RELATIONSHIP*1..3]->(m)
SET m:LABEL
WITH m
MATCH (m)-[r2:RELATIONSHIP]->(q:OTHERLABEL)
WHERE r2.time<100
RETURN m,r2,q;