Dart APIunself_local_databaseCollectionCompanionupdateRule updateRule property Null safety Value<String?> updateRule final Implementation final Value<String?> updateRule; unself_local_database unself_local_database CollectionCompanion updateRule property CollectionCompanion class Constructors CollectionCompanion insert Properties created createRule deleteRule extra hashCode id listRule name runtimeType system type updated updateRule viewRule Methods copyWith noSuchMethod toColumns toString Operators operator == Static methods custom