DataTable dt1 = new DataTable();
        dt1.Columns.Add("id", typeof(int));
        dt1.Rows.Add(1);
        dt1.Rows.Add(2);
        DataTable dt2 = dt1.Clone();
        dt2.Rows.Add(11);
        dt2.Rows.Add(12);
        DataTable dt = new DataTable();
        dt.Merge(dt1);
        dt.Merge(dt2);
        DataSet ds = new DataSet();
        ds.Tables.Add(dt);
        ds.Tables.Add(dt1);
        ds.Tables.Add(dt2);
        DataRelation dataRelation1 = new DataRelation(null, dt.Columns[0], dt1.Columns[0]);
        DataRelation dataRelation2 = new DataRelation(null, dt.Columns[0], dt2.Columns[0]);
        ds.Relations.Add(dataRelation1);
        ds.Relations.Add(dataRelation2);
        dt.Rows[0]["id"] = 100;        //修改合并表中原表1的某个值
        dt.Rows[3]["id"] = 9999;    //修改合并表中原表2的某个值
        GridView1.DataSource = dt1;
        GridView1.DataBind();
        GridView2.DataSource = dt2;
        GridView2.DataBind();
        GridView3.DataSource = dt;
        GridView3.DataBind();