// TODO : add reset is_sold_today and number_sold_today
 public static void addProduct(Product newProduct)
 {
     //openConnection();
     MySqlCommand command = l_DBConn.CreateCommand();
     try
     {
         String query = "REPLACE product(barcode,number_in_stock,name,category,price,manufacturer) VALUES('" + newProduct.getBarcode() + "','" + newProduct.getNumberInStock().ToString() +
                         "','" + newProduct.getName() + "','" + newProduct.getCategory() +
                         "','" + newProduct.getPrice().ToString() + "','" + newProduct.getManufacturer() + "')";
         command.CommandText = query;
         command.ExecuteNonQuery();
     }
     catch { };
     //closeConnection();
 }
 public static void modifyProduct(Product changedProduct)
 {
     //openConnection();
     MySqlCommand command = l_DBConn.CreateCommand();
     try
     {
         String query = "UPDATE product SET number_in_stock='" + changedProduct.getNumberInStock() +
                         "' ,name='" + changedProduct.getName() + "' ,category='" + changedProduct.getCategory() +
                         "' ,price='" + changedProduct.getPrice() + "' ,manufacturer='" + changedProduct.getManufacturer() +
                         "' WHERE barcode ='" + changedProduct.getBarcode() + "'";
         command.CommandText = query;
         command.ExecuteNonQuery();
     }
     catch { };
     //closeConnection();
 }