public void DeleteTraining(int trainingId)
{
//Check if training is booked by employees and in status in process
List <TrainingBookingEntry> entries = db.GetBookingsWithStatus(trainingId, (int)TrainingStatus.InProcess);
//if not, proceed, else throw an exception
if (entries.Count == 0)
{
db.DeleteTraining(trainingId);
Training.Trainings = db.GetTrainings();
}
else
{
throw new TrainingPlatformException("There are employee which are currently undergo this training and therefor it can not be deleted.");
}
}