Dart APIunself_local_databaseCollectionDaocollection collection property Null safety $CollectionTable collection Implementation $CollectionTable get collection => attachedDatabase.collection; unself_local_database unself_local_database CollectionDao collection property CollectionDao class Constructors CollectionDao Properties attachedDatabase collection connection executor field hashCode options resolvedEngine runtimeType streamQueries typeMapping Methods $expandVar $write $writeInsertable alias batch createStream customInsert customSelect customSelectQuery customStatement customUpdate customWriteReturning delete deleteCollection doWhenOpened getCollectionById into markTablesUpdated noSuchMethod notifyUpdates saveCollection select selectOnly tableUpdates toString transaction update Operators operator ==