Add constraints to neo4j node based on node property value

Question

I am adding constraints to a neo4j database using Cypher constraints and want to create a constraint which only applies to a subset of a node type.

I can create a constr

Answer 1

Instead of adding a flag property, you can just add an additional label (say, ConstrainedEntity) to Entity nodes that should be constrained. Queries can continue to use just the Entity label.

For example:

CREATE CONSTRAINT ON (ce:ConstrainedEntity) ASSERT EXISTS (ce.foo)

To create a "flagged" Entity:

CREATE (e:Entity:ConstrainedEntity {id: 111, foo: 'bar'})

To "flag" an existing Entity:

MATCH (e:Entity)
WHERE e.id = 123
SET e:ConstrainedEntity