static void Main(string[] args)
        {
            const string ConnectionString = @"
                        User=SYSDBA;Password=masterkey;
                        Database=D:\\firebird\KCRM.FDB;DataSource=localhost;
                        Port=3050;Dialect=3;Charset=NONE;Role=;Connection lifetime=15;Pooling=true;
                        MinPoolSize=0;MaxPoolSize=50;Packet Size=8192;ServerType=0;";

            string fbSelectCommand = @"select USER_NAME from USERS";
            using (FbConnection con = new FbConnection(ConnectionString))
            {
                con.Open();
                Console.WriteLine("Reading from FireBird DB query - {0}", fbSelectCommand);

                using (FbCommand fbCommand = new FbCommand(fbSelectCommand, con))
                {
                    using (FbDataReader reader = fbCommand.ExecuteReader())
                    {
                        if (reader != null)
                        {
                            while (reader.Read())
                            {

                                string userName = (string)reader["USER_NAME"];
                                Console.WriteLine("{0}", userName);
                            }
                        }
                    }
                }
            }
        }