using System;

using System.Data;

using System.Xml;

public class Program

{

    public static void Main()

    {

      var table1 = new DataTable("Items");

      var col1 = new DataColumn("PKey", typeof(int));

      var col2 = new DataColumn("Val", typeof(int));

      var col3 = new DataColumn("RowVersion", typeof(int));

      table1.Columns.Add(col1);

      table1.Columns.Add(col2);

      table1.Columns.Add(col3);

      table1.PrimaryKey = new[] { col1 }; // If you comment out this line of code, then the rows are just stacked instead of merged.

      for (var i = 0; i <= 9; i++)

      {

        var row = table1.NewRow();

        row["PKey"] = i;

        row["Val"] = i;

        row["RowVersion"] = i;

        table1.Rows.Add(row);

      }

      table1.AcceptChanges();

      var table2 = table1.Clone();

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

      for (var i = 0; i <= 9; i++)

      {

        var row = table2.NewRow();

        row["PKey"] = i;

        row["Val"] = i;

        row["RowVersion"] = i;

        table2.Rows.Add(row);

      }

​

      PrintValues(table1, "table1");

      PrintValues(table2, "table2");

      table1.Merge(table2, false, MissingSchemaAction.Ignore);

      PrintValues(table1, "table1 merged with table2");

    }

​

    private static void PrintValues(DataTable table, string label)

    {

      // Display the values in the supplied DataTable:

      Console.WriteLine(label);

      foreach (DataRow row in table.Rows)

      {

        foreach (DataColumn col in table.Columns)

        {

          Console.Write("\t " + row[col].ToString());

        }

        Console.WriteLine();

      }

    }

}