Comments by kakani santosh kumar (Top 2 by date)

 DataTable dt3 = new DataTable("dt3");
        c12 = new DataColumn("empno");
        c22 = new DataColumn("empname");
        c32 = new DataColumn("depno");
        c42 = new DataColumn("depname");
        dt3.Columns.Add(c12); dt3.Columns.Add(c22); dt3.Columns.Add(c32); dt3.Columns.Add(c42);


        ds.Relations.Add("DepEmp", ds.Tables["dt1"].Columns[2], ds.Tables["dt2"].Columns[0]);
        foreach (DataRow dr in ds.Tables[0].Rows)
        {
            r = dt3.NewRow();
            r[0]= dr["empno"];
            r[1] = dr["empname"];

           
            foreach (DataRow Er in dr.GetChildRows("DepEmp"))
            {
               r[2]=Er["depno"];
                r[3]=Er["depname"];
            }
        
        }