Insert into the database mdf does not working

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C#

SQL

Hi,

I can read datas from MDF but cannot save. My codes are below. I do stuffs inside DatabaseConfig.cs and send values from SalesScreen.cs

What I have tried:

DatabaseConfig.cs:

SqlConnection connect = new SqlConnection("Data Source=(LocalDB)\\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\\BombusDB.mdf;Integrated Security=True;");

        public int buyerCheckAndSave(string buyerPhone, string buyerName, string buyerAddress, bool containsItem)
        {
            int buyerID = 0;
            if (containsItem) //if customer exist just find id.
            {

                connect.Open();
                SqlCommand comm = new SqlCommand("SELECT TOP(1) ID FROM buyer_Tab WHERE pho LIKE @pho ORDER BY ID");
                comm.Parameters.AddWithValue("@pho", '%' + buyerPhone + '%');
                comm.Connection = connect;
                using (SqlDataReader ctr = comm.ExecuteReader())
                {
                    while (ctr.Read())
                    {
                        buyerID = ctr.GetInt32(0);
                    }
                }
                connect.Close();


                return buyerID;
            }
            else //if not first save
            {
                try
                {
                    connect.Open();
                    SqlCommand comm = new SqlCommand("INSERT INTO buyer_Tab (customer, pho, adr) VALUES ('@customer', '@pho', '@adr')");
                    comm.CommandType = CommandType.Text;
                    comm.Connection = connect;
                    comm.Parameters.AddWithValue("@customer", buyerName);
                    comm.Parameters.AddWithValue("@pho", buyerPhone);
                    comm.Parameters.AddWithValue("@adr", buyerAddress);
                    comm.ExecuteNonQuery();

                    connect.Close();
                }
                catch(SqlException e)
                {
                    System.Windows.Forms.MessageBox.Show("Hata Olustu! \n" + e);
                }

                buyerCheckAndSave(buyerPhone, buyerName, buyerAddress, true); //after saving get id
            }
            return buyerID;
        }

SalesScreen.cs (Winforms)

private void sellBtn_Click(object sender, EventArgs e)
        {
            billPrintDialog.Document = printBill;
            billPrintDialog.ShowDialog();
            printBill.Print();
            int customerID = 0;
            if (!String.IsNullOrEmpty(phoneTB.Text))
            {
                bool containsItem = customerPhones.Any(item => item.StartsWith(phoneTB.Text)); //We have existing customers on list
                customerID = db.buyerCheckAndSave(phoneTB.Text, nameTB.Text, adrRTB.Text, containsItem);
            }
            MessageBox.Show(""+customerID);
        }