Return node if relationship is not present

Update 01/10/2013:

Came across this in the Neo4j 2.0 reference:

Try not to use optional relationships.
Above all,

don’t use them like this:

MATCH a-[r?:LOVES]->() WHERE r IS NULL where you just make sure that they don’t exist.

Instead do this like so:

MATCH a WHERE NOT (a)-[:LOVES]->()

Using cypher for checking if relationship doesn’t exist:

...
MATCH source-[r?:someType]-target
WHERE r is null
RETURN source

The ? mark makes the relationship optional.

In neo4j 2 do:

...
OPTIONAL MATCH source-[r:someType]-target
WHERE r is null
RETURN source

Now you can check for non-existing (null) relationship.