public void TestRecalculateBallance()
        {
            var srv = new Servise();

            srv.RecalculateBallance("5111111111111111");
            srv.RecalculateBallance("5111111111111112");

            using (var ctx = new Bank1Entities())
            {
                var card1 = ctx.Card.Single(c => c.CadrID == "5111111111111111");
                var card2 = ctx.Card.Single(c => c.CadrID == "5111111111111112");

                Assert.AreEqual(0, card1.Ballance + card2.Ballance);
            }
        }
        public void RecalculateBallance(string cardNo)
        {
            using (var ctx = new Bank1Entities())
            {
                var card = ctx.Card.SingleOrDefault(c => c.CadrID == cardNo);


                ctx.Entry(card).Collection(c => c.Operations).Load();
                ctx.Entry(card).Collection(c => c.Operations1).Load();

                card.Ballance =
                    card.Operations.Sum(o => o.Amount) - card.Operations1.Sum(o => o.Amount);

                ctx.SaveChanges();
            }
        }