using System;

using System.Data;

using System.Linq;

using System.Xml;

public class Program

{

    public static void Main()

    {

        DataTable table1 = new DataTable("tabe1");

        DataTable table2 = new DataTable("table2");

        table1.Columns.Add("Drug");

        table1.Columns.Add("col");

​

        table2.Columns.Add("Drug");

        table2.Columns.Add("col");

        table2.Rows.Add(new object[] {"drug1", "abc"} );

        table2.Rows.Add(new object[] {"drug2", "abc"} );

        table2.Rows.Add(new object[] {"drug3", "abc"} );

​

​

        table1.Rows.Add(new object[] {"drug1", "abc"} );

        table1.Rows.Add(new object[] {"drug3", "abc"} );

​

        string results = "";

        foreach (DataRow row1 in table2.Rows)

        {

            int x = 0;

            foreach (DataRow row2 in table1.Rows)

            {

                var array1 = row1.ItemArray;

                var array2 = row2.ItemArray;

                if (array1.SequenceEqual(array2))

                {

                    x = 1;

                    break; // get out of the loop and continue

                }

                else

                {

                    continue;

                }

            }

                if (x == 0)

                {

                    results = results + (row1["Drug"]);

                }

​

        }

        Console.WriteLine("Results ...");

        Console.WriteLine(results);

    }

}