Constraints

UNIQUE constraints prevent duplicate property values across all nodes with a given label.

CREATE CONSTRAINT ON (n:Person) ASSERT n.email IS UNIQUE

Attempting to create a node with a duplicate value will return a typed error.

Drop a constraint#

DROP CONSTRAINT ON (n:Person) ASSERT n.email IS UNIQUE

List constraints#

CALL db.constraints()

Causal constraints#

REQUIRE <prop> CAUSED_BY (:<AnchorLabel>) declares that any write to the named property on a node of the given label must carry a same-transaction :CAUSED_BY edge to a node of the anchor label.

CREATE CONSTRAINT FOR (n:Player)
  REQUIRE confidence CAUSED_BY (:Evidence)

Writes that violate the constraint fail at commit with a typed CAUSED_BY_VIOLATION error and roll back the entire transaction. See Causal Edges for the full discipline.

See Also#

• Indexes — performance indexes
• Causal Edges — the :CAUSED_BY discipline