updating data in DataView

try this..
DataView can be used to modify the actual content in a DataTable.It means adding new rows, sorting and search a table.

con.Open();
       string query = "select * from tab2";
       SqlDataAdapter da = new SqlDataAdapter(query, con);
       con.Close();
       DataSet ds = new DataSet();
       DataView dv = new DataView();
       da.Fill(ds);
       dv = new DataView(ds.Tables[0],"", "name", DataViewRowState.CurrentRows);
       int index = dv.Find("ddd");

       if (index == -1)
       {
       }
       else
       {
           dv[index]["name"] = "aaa";
       }

       grdview.DataSource = (DataTable)dv.ToTable();
       grdview.DataBind();