/// <summary> /// Import registrations from JSON file /// </summary> /// <param name="registrationsFileName">Name of the file to import</param> /// <returns> /// Collection of all imported registrations /// </returns> public async Task <IEnumerable <Registration> > ImportRegistrations(string registrationsFileName) { var registrationsText = await File.ReadAllTextAsync(registrationsFileName); var registrations = JsonSerializer.Deserialize <IEnumerable <Registration> >(registrationsText) !; using var transaction = await Database.BeginTransactionAsync(); Registrations.AddRange(registrations); await SaveChangesAsync(); await transaction.CommitAsync(); return(registrations); }