using System;

using Npgsql;

public class Program

{

    public static void Main()

    {

        string connection_string = "Server=helios-data.postgres.database.azure.com;Database=HELIOS;Port=5432;User Id=alex@helios-data;Password=LucyEB_011015;Ssl Mode=Require;";

        using var conn = new NpgsqlConnection(connection_string);

        conn.Open();

​

        var sql = "SELECT version()";

        var table = "SELECT * FROM Prelim_20200303";

​

        using var cmd = new NpgsqlCommand(table, conn);

​

        var version = cmd.ExecuteScalar().ToString();

        Console.WriteLine($"PostgreSQL version: {version}");

​

        using NpgsqlDataReader rdr = cmd.ExecuteReader();

​

            while (rdr.Read())

            {

                Console.WriteLine("{0} {1} {2}", rdr.GetInt32(0), rdr.GetString(1),

                        rdr.GetInt32(2));

            }     

    }

}