三层 除了用clientdataset,怎么返回一个数据集

三层 除了用clientdataset,如何返回一个数据集
想直接调用中间层的方法返回一个数据集,请问如何能行?或者只能是客户端用clientdataset?

Delphi(Pascal) code

function TServerMethods1.GetGoodsClass(BigClass: string): TDataSet;var  SQLTemp: string;begin  with sqldtst_GoodsClass do  begin    Close;    if BigClass = '' then      SQLTemp := 'select b_Name from t_BigClass order by b_Sort'    else      SQLTemp := 'select s_Name from t_BigClass,t_SubClass where b_Name = :p_Name ' +        'and b_ID =s_b_ID order by s_Sort';    CommandText := SQLTemp;    Open;    Result :=  end;end;