Entity Framework

entities.cs

for (var round = 1; round <= width; round++)
{
    // Round
    var tournamentRound = new SingleKnockoutRound();
    tournamentRound.Tournament = this;
    tournamentRound.Matches = new List<TournamentMatch>();
    dbContext.TournamentRounds.Add(tournamentRound);
    this.Rounds.Add(tournamentRound);

    for (var m = 0; m < nrOfMatches; m++)
    {
        // TournamentMatch
        var tournamentMatch = new TournamentMatch();
        dbContext.TournamentMatches.Add(tournamentMatch);
        tournamentRound.Matches.Add(tournamentMatch);

        // Match
        var match = new Match();
        dbContext.Matches.Add(match);
        tournamentMatch.Match = match;

    }
}