using System;

using System.Data;

using Microsoft.Data.Sqlite;

​

public class Program

{

    public static void Main()

    {

        const string connectionString = "Data Source=InMemorySample;Mode=Memory;Cache=Shared";

        using(var connection = new SqliteConnection(connectionString))

        {

            var query = connection.CreateCommand();

            connection.Open();

            query.CommandText = "SELECT 666 ID UNION ALL SELECT CAST(NULL AS INT)";

            using(var reader = query.ExecuteReader())

            {

                var dataTable = new DataTable();

                dataTable.Load(reader);

                var rowCount = 0;

                foreach (DataRow item in dataTable.Rows)

                { 

                    Console.WriteLine($"ROW: {++rowCount}");

                    DBNull.Value.Equals(item[0]).Dump();

                    var objValue =  item.Field<long?>(0).ToString(); //long not int because of SQLite

                    objValue.Dump();

                }

            }

        }

    }

}