PROPERTY_EXISTS

The second argument is a property name, not a string-valued expression.

MATCH (p:Person)
RETURN p.name AS name, PROPERTY_EXISTS(p, age) AS has_age ORDER BY name;

The predicate is false for a missing property or a property whose value is null. For a null element introduced by OPTIONAL MATCH, the result is null rather than false.

Graph storage distinguishes layout membership from a present null value, but this predicate deliberately tests non-null property presence. Use p.age IS NULL when you need a null test on the projected value.