// C# Extension Method

// Doc: https://csharp-extension.com/en/method/1002776/idatareader-isdbnull

​

// @nuget: Z.ExtensionMethods

​

using System;

using System.Data;

using System.Data.Common;

using System.Data.SqlClient;

public class Program

{

    public static void Main()

    {

        const string sql = @"SELECT 1, NULL";

        using (var conn = new SqlConnection(FiddleHelper.GetConnectionStringSqlServer()))

        {

            conn.Open();

            using (DbCommand command = conn.CreateCommand())

            {

                command.CommandText = sql;

                using (IDataReader reader = command.ExecuteReader())

                {                   

                    while (reader.Read())

                    {

                        //C# Extension Method: IDataReader - IsDBNull

                        bool result1 = reader.IsDBNull(0); // return false;

                        bool result2 = reader.IsDBNull(1); // return true;

                        Console.WriteLine(result1);

                        Console.WriteLine(result2);

                    }

                }

            }

        }

    }

}