User-707554951 posted
Hi guhananth,
From your description, you want copy datatable in your two datasets to a single dataset;
If that the case, following working sample for your reference:
<asp:GridView ID="GridView1" runat="server"></asp:GridView>
<hr />
<asp:GridView ID="GridView2" runat="server"></asp:GridView>
protected void Page_Load(object sender, EventArgs e)
{
DataTable t1 = new DataTable();
t1.Columns.Add("key1");
t1.Columns.Add("c1");
t1.PrimaryKey = new[] { t1.Columns["key1"] };
t1.Rows.Add(1, "data1");
t1.TableName = "table1";
// This is table two.
DataTable t2 = new DataTable();
t2.Columns.Add("key1");
t2.Columns.Add("c2");
t2.PrimaryKey = new[] { t2.Columns["key1"] };
t2.TableName = "table2";
t2.Rows.Add(1, "data2");
DataSet dataSet = new DataSet("dataSet");
dataSet.Tables.Add(t1);
DataSet dataSet2 = new DataSet("dataSet");
dataSet2.Tables.Add(t2);
DataSet dsResult = new DataSet("dsResult");
foreach(DataTable dt in dataSet.Tables)
{
dsResult.Tables.Add(dt.Copy());
}
foreach (DataTable dt2 in dataSet2.Tables)
{
dsResult.Tables.Add(dt2.Copy());
}
GridView1.DataSource = dsResult.Tables[0];
GridView1.DataBind();
GridView2.DataSource = dsResult.Tables[1];
GridView2.DataBind();
}
Output:

Besides, you could learn basic knowledge by referring to the following links;
https://docs.microsoft.com/en-us/dotnet/framework/data/adonet/dataset-datatable-dataview/
https://www.dotnetperls.com/dataset
http://csharp.net-informations.com/dataset/csharp-dataset-tutorial.htm
Best regards
Cathy