Moor: Primary key not inferred when using Dart tables with inheritance

[tugayac]

What was I trying to do?

Setting a primary key on a Table by overriding the primaryKey property of the Table class.

What did I expect to happen?

I have the following code:

my_database.dart

part 'my_database.g.dart';

LazyDatabase _openConnection() {
  return LazyDatabase(() async {
    final dbFolder = await getApplicationDocumentsDirectory();
    final file = File(join(dbFolder.path, 'dev_db.sqlite'));
    print('SQLite File Path: ${file.path}');
    if (kDebugMode) {
      // Does not run in Profile or Release Mode
      if (file.existsSync()) {
        await file.delete();
      }
    }

    return VmDatabase(file, logStatements: true);
  });
}

@UseMoor(
  tables: [Projects],
  daos: [ProjectsDao],
)
class MyDatabase extends _$MyDatabase {
  MyDatabase() : super(_openConnection());

  @override
  int get schemaVersion => 1;

  @override
  MigrationStrategy get migration {
    return MigrationStrategy(
      beforeOpen: (OpeningDetails details) async {
        await customStatement('PRAGMA foreign_keys = ON');
      },
    );
  }
}

projects.dart

class Projects extends EntityWithUuid {
  TextColumn get name => text()();
  TextColumn get client => text().nullable()();
}

entity_with_uuid.dart

abstract class EntityWithUuid extends Table {
  TextColumn get id =>
      text().clientDefault(() => GetIt.instance.get<Uuid>().v4())();

  @override
  Set<Column> get primaryKey => {id};
}

I expected the primary key of the projects table to be the id column

What actually happens?

When the application starts, the following is logged in the console:

flutter: Moor: Sent CREATE TABLE IF NOT EXISTS projects (is_playground_entity INTEGER NOT NULL DEFAULT 0 CHECK (is_playground_entity in (0, 1)), id VARCHAR NOT NULL, name VARCHAR NOT NULL, client VARCHAR NULL, color INTEGER NOT NULL, total_worktime VARCHAR NULL, total_earned VARCHAR NULL, time_goal VARCHAR NULL, budget_goal VARCHAR NULL, goal_type INTEGER NOT NULL DEFAULT 0, PRIMARY KEY (id)); with args []

I noticed that even though I set Set<Column> get primaryKey => {id};, PRIMARY KEY is not set on the id attribute. I verified this using a SQLite browser as well.

In addition, I also got rid of using the EntityWithUuid abstract class you see above, just to make sure it wasn't my code that was causing the problem.

Eventually, I resorted to doing:

@override
  List<String> get customConstraints => [
        'PRIMARY KEY (id)',
      ];

on the table, which works.

Wanted to make sure there isn't any bugs with Set<Column> get primaryKey => {id};. Perhaps I'm doing something wrong in my code?

[simolus3]

Thanks for the report. This is a bug in the generator that will be fixed in the next version.

Until that's released, another workaround (apart from overriding customConstraints) is duplicating the primaryKey getter in the child class:

class Projects extends EntityWithUuid {
  TextColumn get name => text()();
  TextColumn get client => text().nullable()();

  @override
  Set<Column> get primaryKey => {id};
}

Not ideal, but at least you don't have to touch generated code which can be very fragile.

[tugayac]

Gotcha, thanks for another workaround example. Appreciate the quick response!