Cypher/Neo4j – Storing bracketed variable in global scope

Question

The following cypher query fails at the last line because p2 is only defined within scope after EXISTS, but is there a way to bring it out of that scope somehow (e.g. set it to a global variable) and return it?

MATCH (p:Person)
WHERE EXISTS {
  MATCH (p{name: 'José'})<-[:CHILD_OF]-(p2:Person)
  WHERE p2.name IN ['Roberto', 'Gustavo']  
}
RETURN (p), (p2) // fails

P.S.: I know that the easiest solution is to just NOT use the scope in the first place, my question is whether the functionality I'm looking for exists.

Answer 1

Existential queries used in EXISTS cannot return values. You need to use CALL if you want to do post processing of a sub query's results. It looks like you want to try:

MATCH (p:Person)
CALL {
  WITH p
  MATCH (p{name: 'José'})<-[:CHILD_OF]-(p2:Person)
  WHERE p2.name IN ['Roberto', 'Gustavo'] 
  RETURN p2 
}
RETURN p, p2

The WITH in the CALL makes the p from the outer query available to the inner query.

Answer 2

I would have done this:

MATCH (p:Person)<-[:CHILD_OF]-(p2:Person)
WHERE p.name = 'Josè'
AND p2.name IN ['Roberto', 'Gustavo']
RETURN p,p2

Answer 3

You can remove the where exists clause and directly do the query on Jose and his parents.

MATCH (p: Person{name: 'José'})<-[:CHILD_OF]-(p2:Person)
WHERE p2.name IN ['Roberto', 'Gustavo']  
RETURN p, p2