CREATE TABLE [dbo].[Table1] (
	[EmployeeID] [char] (10) 
	COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL ,
	[Name] [char] (10) 
	COLLATE SQL_Latin1_General_CP1_CI_AS NULL
) ON [PRIMARY]

CREATE TABLE [dbo].[Table2] (
	[EmployeeID] [char] (10) 
	COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL ,
	[Department] [char] (10) 
	COLLATE SQL_Latin1_General_CP1_CI_AS NULL
) ON [PRIMARY]

Dim connstr As String = "Integrated Security=SSPI;
User ID=sa;Initial Catalog=Northwind;Data Source=SERVER\netsdk"
Dim cnn As New SqlConnection(connstr)
Dim da1 As New SqlDataAdapter("select * from table1", cnn)
Dim da2 As New SqlDataAdapter("select * from table2", cnn)
Dim ds1 As New DataSet()
Dim ds2 As New DataSet()

da1.Fill(ds1, "table1")
da2.Fill(ds2, "table1")

Dim pk1(0) As DataColumn
Dim pk2(0) As DataColumn

pk1(0) = ds1.Tables(0).Columns("EmployeeID")
ds1.Tables(0).PrimaryKey = pk1

pk2(0) = ds2.Tables(0).Columns("EmployeeID")
ds2.Tables(0).PrimaryKey = pk2

ds1.Merge(ds2, False, MissingSchemaAction.Add)

DataGrid1.DataSource=ds1
DataGrid1.DataBind()

private static void DemonstrateMergeTable()
{
    DataTable table1 = new DataTable("Items");

    // Add columns
    DataColumn idColumn = new DataColumn("id", typeof(System.Int32));
    DataColumn itemColumn = new DataColumn("item", typeof(System.Int32));
    table1.Columns.Add(idColumn);
    table1.Columns.Add(itemColumn);

    // Set the primary key column.
    table1.PrimaryKey = new DataColumn[] { idColumn };

    // Add RowChanged event handler for the table.
    table1.RowChanged += new 
        System.Data.DataRowChangeEventHandler(Row_Changed);

    // Add ten rows.
    DataRow row;
    for (int i = 0; i <= 9; i++)
    {
        row = table1.NewRow();
        row["id"] = i;
        row["item"] = i;
        table1.Rows.Add(row);
    }

    // Accept changes.
    table1.AcceptChanges();
    PrintValues(table1, "Original values");

    // Create a second DataTable identical to the first.
    DataTable table2 = table1.Clone();

    // Add column to the second column, so that the 
    // schemas no longer match.
    table2.Columns.Add("newColumn", typeof(System.String));

    // Add three rows. Note that the id column can't be the 
    // same as existing rows in the original table.
    row = table2.NewRow();
    row["id"] = 14;
    row["item"] = 774;
    row["newColumn"] = "new column 1";
    table2.Rows.Add(row);

    row = table2.NewRow();
    row["id"] = 12;
    row["item"] = 555;
    row["newColumn"] = "new column 2";
    table2.Rows.Add(row);

    row = table2.NewRow();
    row["id"] = 13;
    row["item"] = 665;
    row["newColumn"] = "new column 3";
    table2.Rows.Add(row);

    // Merge table2 into the table1.
    Console.WriteLine("Merging");
    table1.Merge(table2, false, MissingSchemaAction.Add);
    PrintValues(table1, "Merged With table1, schema added");

}

private static void Row_Changed(object sender, 
    DataRowChangeEventArgs e)
{
    Console.WriteLine("Row changed {0}\t{1}", e.Action, 
        e.Row.ItemArray[0]);
}

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();
    }
}