How to implement a generatedAs that needs a join? What would be the correct way?

[Gaweringo]

I basically have two tables with a many-to-many relationship based on the Many-To-Many relationships with JSON documentation:

class Sessions extends Table {
  IntColumn get id => integer().autoIncrement()();

  TextColumn get entries => text().map(SessionGrades.converter)();
}

class Grades extends Table {
  IntColumn get id => integer().autoIncrement()();

  TextColumn get name => text()();

  IntColumn get points => integer()();
}

@JsonSerializable()
class SessionGrades {
  SessionGrades({required this.grades});

  factory SessionGrades.fromJson(Map<String, Object?> json) =>
      _$SessionGradesFromJson(json);

  final List<int> grades;

  Map<String, Object?> toJson() => _$SessionGradesToJson(this);

  static JsonTypeConverter<SessionGrades, String> converter =
      TypeConverter.json(
    fromJson: (json) => SessionGrades.fromJson(json as Map<String, Object?>),
    toJson: (entries) => entries.toJson(),
  );
}

And I would like to add a column to the Sessions that holds the total points from its grades, so that I can later sort the Sessions by their total points/get the Session with the highest total points.

My first thought was to add a column like so:

class Sessions extends Table {
  IntColumn get id => integer().autoIncrement()();

  TextColumn get entries => text().map(SessionGrades.converter)();

  IntColumn get points => integer().generatedAs(/* todo */, stored: true);
}

With the todo section, somehow calculating the sum of the points of all the grades of this session. But it seems that generateAs is not made for such a complex operation.
I'd be interested in how I should go about implementing what I want here, with probably other features.

Should I create a view? But this would have to recompute the value every time.
Or should I just have it be a normal column and update it manually in the functions that log new grades for a session?
A third option would be to maybe look into triggers. Could they be what I am looking for?

[Gaweringo]

Well, it seems like I should have kept on trying the things instead of pondering what the correct thing is for so long.
I have now created a trigger on the update of the entries and it works just how I wanted it to.