Use loop to read all data in SqlDataReader : SqlDataReader « ADO.Net « C# / CSharp Tutorial

1. C# / CSharp Tutorial
2. ADO.Net
3. SqlDataReader

using System;
using System.Data;
using System.Data.SqlClient;

class MainClass
{
   static void Main(string[] args)
   {
      string connString = "server=(local)\\SQLEXPRESS;database=MyDatabase;Integrated Security=SSPI;";

      string sql = @"select firstName from Employee";

      SqlConnection conn = new SqlConnection(connString); 

      try
      {
         conn.Open();

         SqlCommand cmd = new SqlCommand(sql, conn);

         SqlDataReader rdr = cmd.ExecuteReader();

         while (rdr.Read())
         {
            Console.WriteLine("{0}", rdr[0]); 
         }

         rdr.Close();
      }
      catch(Exception e)
      {
         Console.WriteLine("Error Occurred: " + e);
      }
      finally
      {
         conn.Close();
      }
   }
}