Question

I’m getting a parameter and getting a specific product from a stored procedure. This stored procedure is returning many columns (I think around 15-20). Unfortunately, some of these values may be null and this of course produces an error when I try to put them in a variable. Is there a simple way to check and see if these values are NULL so that it doesn’t throw an exception or do I need to put an if statement before each assignment? If it helps, here is my code:

public List<Product> ReadSpecificProductDetails(string productAndURLID)
    {
        ConfigureDataAccess();
        myCommand = new SqlCommand("[dbo].[GetSpecificProductDetails]", myConnection);
        myCommand.CommandType = CommandType.StoredProcedure;
        //myCommand.Parameters.Add(productAndURLID);
        //myCommand.Parameters.Add(new SqlParameter("@ProductID", SqlDbType.SmallInt));
        myCommand.Parameters.AddWithValue("@ProductID", Convert.ToInt16(productAndURLID));

        try
        {
            try
            {
                myConnection.Open();
                myReader = myCommand.ExecuteReader();
            }
            catch (SqlException exception)
            {
                exception.Data.Add("cstring", myConfiguration);
                throw;
            }
            catch (InvalidOperationException ex)
            {
                ex.Data.Add("cStatus", myConnection.State);
                throw;
            }

            //Create a 'Product' list to store the records in
            while (myReader.Read())
            {
                int productID = Convert.ToInt16(myReader["ProductID"]);
                string productName = (string)myReader["Name"];
                string productNumber = (string)myReader["ProductNumber"];
                //int quantitySum = Convert.ToInt16(myReader["QuantitySum"]);
                string productColor = (string)myReader["Color"];
                int productSafetyStockLevel = Convert.ToInt16(myReader["SafetyStockLevel"]);
                int productReorderPoint = Convert.ToInt16(myReader["ReorderPoint"]);
                decimal productStandardCost = Convert.ToDecimal(myReader["StandardCost"]);
                decimal productListPrice = Convert.ToDecimal(myReader["ListPrice"]);
                string productSize = (string)myReader["Size"];
                decimal productWeight = Convert.ToDecimal(myReader["Weight"]);
                int productDaysToManufacture = Convert.ToInt16(myReader["DaysToManufacture"]);
                string productCategoryName = (string)myReader["PC.Name"];
                string productSubCategoryName = (string)myReader["PS.Name"];
                string productModelName = (string)myReader["PM.Name"];
                DateTime productSellStartDate = Convert.ToDateTime(myReader["Sell_Start_Date"]);
                DateTime productSellEndDate = Convert.ToDateTime(myReader["Sell_End_Date"]);
                DateTime productDiscontinuedDate = Convert.ToDateTime(myReader["Discontinued_Date"]);
                Product p = new Product(productID, productName, productNumber, productColor, productSafetyStockLevel, productReorderPoint, productStandardCost,
                    productListPrice, productSize, productWeight, productDaysToManufacture, productCategoryName, productSubCategoryName, productModelName, productSellStartDate,
                    productSellEndDate, productDiscontinuedDate);
                myProducts.Add(p);
            }
        }
        finally
        {
            myReader.Close();
            myConnection.Close();
        }
        return myProducts;
    }

Answer 1

int? x = dt.Field<int?>( "Field" );

Or

int y = dt.Field<int?>( "Field" ) ?? 0;

C# DBNull and nullable Types – cleanest form of conversion

The top is probably your best approach. You currently have some non nullable types you are populating. So if you want to be able to represent them as null use the top approach. Otherwise you can use the other option to give a default value.