Suma TextBox i bazy danych

Witam,
Mam pewien problem.
Mam program, który posiada dwa textBoxy (Suma i różnica), chciałbym aby wartość z textboxa "suma" była dodana do wartości w danej komórce bazy danych SQL i analogicznie to samo z różnicą.

private void button_save_Click(object sender, EventArgs e)
        {

            SqlConnection conn = new SqlConnection(@"Data Source=(LocalDB)\v11.0;AttachDbFilename=//Database.mdf;Integrated Security=True");
			
            string updateSQL = "";
            if (comboBox_1.Text == "1")
                updateSQL = "UPDATE Karabinczyk SET [1] = @Value WHERE [typ] = @typ";
            else if (comboBox_2.Text == "2")
                updateSQL = "UPDATE Karabinczyk SET [2] = @Value WHERE [typ] = @typ";
            else if (comboBox_3.Text == "3")
                updateSQL = "UPDATE Karabinczyk SET [3] = @Value WHERE [typ] = @typ";
            else if (comboBox_4.Text == "4")
                updateSQL = "UPDATE Karabinczyk SET [4] = @Value WHERE [typ] = @typ";

            SqlCommand command = new SqlCommand(updateSQL, conn);
            
            command.Parameters.AddWithValue("@Value", ((int.Parse(textBox_roznica.Text) * -1) + (int.Parse(textBox_suma.Text))));
            command.Parameters.AddWithValue("@typ", comboBox_typ.Text);
            command.Connection = conn;
            conn.Open();
            command.ExecuteNonQuery();
            conn.Close();

Kod ten działa tak, że po wykonaniu go podmienia wartości bazy, a nie sumuje czy odejmuje,

może by tak:

UPDATE Karabinczyk SET [1] = @Value + [1] WHERE [typ] = @typ

No i wywal te paskudne ify. Nie widzisz powiązania między tekstem w combo, a zapytaniem?

Dziadu napisał(a):

może by tak:

UPDATE Karabinczyk SET [1] = @Value + [1] WHERE [typ] = @typ

Niestety nie podziała :/

mr-owl napisał(a):

może by tak:

A nie możesz "po bożemu" zrobić zrobić dwóch funkcji które odpowiadają za aktualizację właściwych danych albo zrobić całość za pomocą repozytorium? Masz obiekty swojego typu które reprezentują jednemu wierszowi w tabeli, zaczytujesz rekord, modyfikujesz go i aktualizujesz bazę danych. Po co takie kombinowanie?

a mógłbyś mi dokładniej wytłumaczyć o co chodzi. Znaczy się wiem o co, ale nie wiem jak to poprawnie napisać :/

Witam,

Tak na szybko i poglądowo robisz coś takiego:

namespace FourProgrammersSample
{
    using System;
    using System.Collections.Generic;
    using System.Data.SqlClient;
    using System.Linq;

    public class Carabiner : IComparable<Carabiner>, IEquatable<Carabiner>
    {
        public int Id { get; set; }

        public string Value1 { get; set; }

        public string Value2 { get; set; }

        public int CompareTo(Carabiner other)
        {
            return this.Id.CompareTo(other.Id);
        }

        public bool Equals(Carabiner other)
        {
            return other != null && this.Id.Equals(other.Id);
        }
    }

    interface IGenericRepository<TEntity, in TKey>where TEntity : class
    {
        void Create(TEntity entity);
        TEntity Retrieve(TKey id);
        void Update(TEntity entity);
        void Delete(TKey id);
        IEnumerable<TEntity> List();
    }

    interface ICarabinerRepository : IGenericRepository<Carabiner, int>
    {
    }

    public sealed class CarabinerRepository : ICarabinerRepository
    {
        private readonly string connectionString;

        public CarabinerRepository(string connectionString)
        {
            this.connectionString = connectionString;
        }

        public void Create(Carabiner entity)
        {
            try
            {
                using (var connection = new SqlConnection(this.connectionString))
                {
                    connection.Open();

                    using (var command = connection.CreateCommand())
                    {
                        command.CommandText = "INSERT INTO [dbo].[carabiner] VALUES (@id, @value1, @value2)";

                        command.Parameters.AddWithValue("@id", entity.Id);
                        command.Parameters.AddWithValue("@value1", entity.Value1);
                        command.Parameters.AddWithValue("@value2", entity.Value2);

                        command.ExecuteNonQuery();
                    }
                }
            }
            catch (Exception exception)
            {
                Console.WriteLine(exception);
            }
        }

        public Carabiner Retrieve(int id)
        {
            Carabiner record = null;

            try
            {
                using (var connection = new SqlConnection(this.connectionString))
                {
                    connection.Open();

                    using (var command = connection.CreateCommand())
                    {
                        command.CommandText = "SELECT id, value1, value2 FROM [dbo].[carabiner] WITH (nolock) WHERE id = @id";

                        command.Parameters.AddWithValue("@id", id);

                        using (var reader = command.ExecuteReader())
                        {
                            while (reader.Read())
                            {
                                var value1 = reader.GetString(reader.GetOrdinal("value1"));
                                var value2 = reader.GetString(reader.GetOrdinal("value2"));

                                record = new Carabiner { Id = id, Value1 = value1, Value2 = value2 };
                            }
                        }
                    }
                }
            }
            catch (Exception exception)
            {
                Console.WriteLine(exception);
            }

            return record;
        }

        public void Update(Carabiner entity)
        {
            try
            {
                using (var connection = new SqlConnection(this.connectionString))
                {
                    connection.Open();

                    using (var command = connection.CreateCommand())
                    {
                        command.CommandText =
                            "UPDATE [dbo].[carabiner] SET value1 = @value1, value2 = @value2 WHERE id = @id";

                        command.Parameters.AddWithValue("@id", entity.Id);
                        command.Parameters.AddWithValue("@value1", entity.Value1);
                        command.Parameters.AddWithValue("@value2", entity.Value2);

                        command.ExecuteNonQuery();
                    }
                }
            }
            catch (Exception exception)
            {
                Console.WriteLine(exception);
            }
        }

        public void Delete(int id)
        {
            try
            {
                using (var connection = new SqlConnection(this.connectionString))
                {
                    connection.Open();

                    using (var command = connection.CreateCommand())
                    {
                        command.CommandText = "DELETE FROM [dbo].[carabiner] WHERE id = @id";

                        command.Parameters.AddWithValue("@id", id);

                        command.ExecuteNonQuery();
                    }
                }
            }
            catch (Exception exception)
            {
                Console.WriteLine(exception);
            }
        }

        public IEnumerable<Carabiner> List()
        {
            var list = new List<Carabiner>();

            try
            {
                using (var connection = new SqlConnection(this.connectionString))
                {
                    connection.Open();

                    using (var command = connection.CreateCommand())
                    {
                        command.CommandText = "SELECT id, value1, value2 FROM [dbo].[carabiner] WITH (nolock)";

                        using (var reader = command.ExecuteReader())
                        {
                            while (reader.Read())
                            {
                                var id = reader.GetInt32(reader.GetOrdinal("id"));
                                var value1 = reader.GetString(reader.GetOrdinal("value1"));
                                var value2 = reader.GetString(reader.GetOrdinal("value2"));

                                list.Add(new Carabiner { Id = id, Value1 = value1, Value2 = value2 });
                            }
                        }
                    }
                }
            }
            catch (Exception exception)
            {
                Console.WriteLine(exception);
            }

            return list;
        }
    }

    static class Program
    {
        static void Main()
        {
            var connectionString =
                @"Data Source=(LocalDB)\v11.0;AttachDbFilename=Database.mdf;Integrated Security=True";
            ICarabinerRepository repository = new CarabinerRepository(connectionString);

            repository.Create(new Carabiner{Id = 1, Value1 = "CBA", Value2 = "CBA"});

            var record = repository.Retrieve(1);

            if (record != null)
            {
                record.Value1 = "ABC";
                record.Value2 = "ABC";

                repository.Update(record);
            }

            repository.Delete(1);

            repository.Create(new Carabiner { Id = 2, Value1 = "AAA", Value2 = "AAA" });
            repository.Create(new Carabiner { Id = 3, Value1 = "AAA", Value2 = "BBB" });
            repository.Create(new Carabiner { Id = 4, Value1 = "ABC", Value2 = "CCC" });


            var items = repository.List();


            foreach (var item in (from item in items where item.Value1.Equals("AAA") select item).ToArray())
            {
                item.Value2 = "BBB";
                repository.Update(item);
            }

        }
    }
}

Pozdrawiam,

mr-owl