perform a select in npgsql c#
using System;
using Npgsql;
class Sample
{
static void Main(string[] args)
{
// Connect to a PostgreSQL database
NpgsqlConnection conn = new NpgsqlConnection("Server=127.0.0.1;User Id=postgres; " +
"Password=pwd;Database=postgres;");
conn.Open();
// Define a query
NpgsqlCommand command = new NpgsqlCommand("SELECT city, state FROM cities", conn);
// Execute the query and obtain a result set
NpgsqlDataReader dr = command.ExecuteReader();
// Output rows
while (dr.Read())
Console.Write("{0}\t{1} \n", dr[0], dr[1]);
conn.Close();
}
}