Find Neo4j nodes where the property is not set

Question

Using Cypher, how can I find a node where a property doesn't exist?

For example, I have two nodes:

A = {foo: true, name: 'A'},  B = { name: 'B'}

Now I'd like to find B, selecting it on the basis of not having the foo property set. How can I do this?

Mellie

Answer 1

As Michael Hunger mentioned

MATCH (n) WHERE NOT EXISTS(n.foo) RETURN n

On older versions of Neo4j you can use HAS:

# Causes error with later versions of Neo4j
MATCH (n) WHERE NOT HAS(n.foo) RETURN n

Angellaangelle

use NOT exists(n.foo) for future compatibility. – Adolescent

Has is no longer supported by Neo4j and produces an error – Multiplicate

You can also use IS NULL and IS NOT NULL. For example MATCH (n) WHERE n.foo IS NULL RETURN n – Moreta

This answer is no longer correct, as EXISTS has long been deprecated. – Zsazsa

Answer 2

As of version 4.3 EXISTS has been deprecated on properties and instead, you should use IS NOT NULL.

So for the example in your question your query would now be:

MATCH (n) WHERE n.foo IS NULL RETURN n

Zsazsa

This should be set as the correct answer. Is still the case as of 2024 – Deforce

I agree, but by the time it makes it up the list it might be irrelevant... haha – Zsazsa

Answer 3

MATCH (f) WHERE f.foo IS NULL RETURN f

Mellie