请问怎么给decisioncube写代码?(大家帮帮忙啊)

Question

暂时手头没有详细的decisioncube代码的书自己胡写了几句,如下:
decisionquery1.Close;
decisionquery1.SQL.Clear;
decisionquery1.SQL.Add('select num,sum(income) from sell where num=:a and month1=:b group by num');
decisionquery1.ParamByName('a').AsString:=combobox1.Text;
decisionquery1.ParamByName('b').AsString:=combobox2.Text;
decisioncube1.MaxCells:=50;
decisioncube1.MaxDimensions:=5;
decisioncube1.MaxSummaries:=10;
decisioncube1.DataSet:=DecisionQuery1;
decisioncube1.Active:=true;
decisionquery1.Open;
结果果然出错,系统提示我:cannot build the Decison cube with an empty data set,请问我该怎么写这段代码?

Answer 1

decisioncube1.Active:=true;
decisionquery1.Open;
//激活的顺序是否应该调换一下

Answer 2

decisionquery1.Close;
decisionquery1.SQL.Clear;
decisionquery1.SQL.Add('select num,sum(income) from sell where num=:a and month1=:b group by num');
decisionquery1.ParamByName('a').AsString:=combobox1.Text;
decisionquery1.ParamByName('b').AsString:=combobox2.Text;
decisioncube1.MaxCells:=50;
decisioncube1.MaxDimensions:=5;
decisioncube1.MaxSummaries:=10;
decisionquery1.Open;
decisioncube1.DataSet:=DecisionQuery1;
decisioncube1.Active:=true;

Answer 3

outer2000(天外流星) :这样也不行,还是那个错误,是不是我还有什么属性没有写??