public void Insert(FlashcardDbModel flashcardDbModel)
 {
     using (var db = new FlashcardDbContextPostgreSQL())
     {
         db.FlashcardsDbModels.Add(flashcardDbModel);
         db.SaveChanges();
     }
 }
 public void Insert(GroupDbModel groupDbModel)
 {
     using (var db = new FlashcardDbContextPostgreSQL())
     {
         db.GroupDbModels.Add(groupDbModel);
         db.SaveChanges();
     }
 }
        public void Update(FlashcardDbModel input)
        {
            using (var db = new FlashcardDbContextPostgreSQL())
            {
                FlashcardDbModel flashcard = db.FlashcardsDbModels.Find(input.Id, input.PracticeDirection);

                flashcard.CorreactAnsInRow = input.CorreactAnsInRow;
                flashcard.NextPracticeDate = input.NextPracticeDate;

                db.SaveChanges();
            }
        }