CALL apoc.trigger.add( 'setVendorUUID', ' UNWIND apoc.trigger.nodesByLabel($assignedLabels, "Vendor") AS n SET n.uuid = COALESCE(n.uuid, apoc.create.uuid()) ', {phase: 'before'} ); MATCH (v:Vendor) WHERE v.uuid is null SET v.uuid = apoc.create.uuid();