using System;

using System.Linq;

using System.Data;

using System.Xml;

using System.Collections;

using System.Collections.Generic;

using System.Data.DataSetExtensions;

​

public class Program

{

    public static void Main()

    {

        ////Sample Data

                DataTable table1 = new DataTable();

                table1.Columns.Add("PersonName", typeof(string));

                table1.Rows.Add("Chandru");

                table1.Rows.Add("Ramya");

                table1.Rows.Add("Charu");

​

                DataTable table2 = new DataTable();

                table2.Columns.Add("PersonName", typeof(string));

                table2.Columns.Add("FeesPaid", typeof(int));

                table2.Rows.Add("Chandru",3000);

                table2.Rows.Add("Ramya",4000);

​

                DataTable table3 = new DataTable();

                IEnumerable<string> idsInA = table1.AsEnumerable().Select(row => (string)row["PersonName"]);

                IEnumerable<string> idsInB = table2.AsEnumerable().Select(row => (string)row["PersonName"]);

                IEnumerable<string> usernotpaidfeee = idsInA.Except(idsInB);

                foreach (string userName in usernotpaidfeee)

                    Console.WriteLine(userName);

    }

}