using System;

using System.Data;

using System.Xml;

​

namespace DataTableReaderDemon

{

    public static class Program

    {

        public static void Main()

        {

            const string CONSOLE_MASK = "ID: {0}, First: {1}, Last: {2}, Birth Date: {3}";

            var dt = DataTableBuilder.GetSampleDataTable();

            var reader = new DataTableReader(dt);

            while (reader.Read())

            {

                Console.WriteLine(

                    CONSOLE_MASK,

                    reader.GetDbNullInt(0, 0),

                    reader.GetDbNullString(1, "First"),

                    reader.GetDbNullString(2, "Last" ),

                    reader.GetDbNullDateTime(3, new DateTime(1900,12,31))

                    );

            }

        }

    }

​

    internal static class DataTableBuilder

    {

        internal static DataTable GetSampleDataTable()

        {

            var result = new DataTable();

            result.Columns.Add("Id", typeof (int));

            result.Columns.Add("FirstName", typeof(string));

            result.Columns.Add("LastName", typeof(string));

            result.Columns.Add("Birthdate", typeof (DateTime));

            result.Rows.Add(new object[] { DBNull.Value, DBNull.Value, DBNull.Value, DBNull.Value });

            result.Rows.Add(new object[] {1, "Bill", "Bunion", new DateTime(2000, 1, 23)});

            result.Rows.Add(new object[] {2, "Sally", "Smith", new DateTime(1999, 12, 31)});

            return result;

        }

    }

    internal static class DataTableReaderExtensions

    {

        internal static string GetDbNullString

        (

            this DataTableReader reader, 

            int ordinalPosition, 

            string valueIfNull

        )

        {

            var result = reader.IsDBNull(ordinalPosition) 

                ? valueIfNull 

                : reader.GetString(ordinalPosition);

            return result;

        }

​

        internal static int GetDbNullInt

        (

            this DataTableReader reader,

            int ordinalPosition,

            int valueIfNull

        )

        {

            var result = reader.IsDBNull(ordinalPosition)

                ? valueIfNull

                : reader.GetInt32(ordinalPosition);

            return result;

        }

​

        internal static DateTime GetDbNullDateTime

        (

            this DataTableReader reader,

            int ordinalPosition,

            DateTime valueIfNull

        )

        {

            var result = reader.IsDBNull(ordinalPosition)

                ? valueIfNull

                : reader.GetDateTime(ordinalPosition);

            return result;

        }

    }

}

​