delphi DataSet读写

DBGridEh1.DataSource.DataSet.Open;
  while not DBGridEh1.DataSource.DataSet.Eof do
  begin
    {showmessage(‘CID : ‘+string(DBGridEh1.DataSource.DataSet.FieldByName(‘CID‘).Value) +
        ‘--科目 :‘ + string(DBGridEh1.DataSource.DataSet.FieldByName(‘科目‘).Value) +
        ‘--章节 :‘ + string(DBGridEh1.DataSource.DataSet.FieldByName(‘章节‘).Value)
        ) ;   }
    DBGridEh1.DataSource.DataSet.Edit;
    DBGridEh1.DataSource.DataSet.FieldByName(‘章节‘).Value:=‘ww‘;
    DBGridEh1.DataSource.DataSet.Post;
    DBGridEh1.DataSource.DataSet.Next ;
  end ;