variables / aggregates

zifnabbe

Hi,

I'm sorry, this must be simple, but I'm unable to find out how to use aggregates in a header band...
I'm following the intructions in the manual (double pass & OnBeforePrint events with Get/Set)

So far I was't able to use my own declared variables eg <Group."Total"> & <Group."StartDate">
I do get errors as "could not convert variant of type (null) into type (OleStr). Unknown variable or datafield: Group."Total"

Set(<Group."Total">, SUM(...));

The variable does however exists...

I also noticed that you get another error when you haven't set an expression in your variable.

Finally I just used a datafield (as shown in the manual) and this works. At least for my totals.

Is this normal?? How can I use custom variables?

Further, how do I format a date variable ? Set(<Customers."CUSTOMER_DATE">, MIN(<Customers."INVOICE_DATE">, masterdetail1)

If I want to use this as Memo1.Text := 'Month : '+FormatDateTime('mmmm', Get(<Customers."CUSTOMER_DATE">). But this doesn't work. I get errors on this

Last question:
Is there a way to fill in variables and just use these inside a text object of the report gui? Do you realy need to use the code as in memo1.txt?

Thanks in advance,

technisoft

There are 2 kinds of variables in FR. Categorized variable and non-categorized one.
For the first kind you use Get() and Set()
Look at this thread which deals with a similar problem.
http://www.fast-report.com/en/forum/?p=/discussion/9134
These variables can be referred to like table columns.

The second kind you use like ordinary Pascal variable. However, they are run-time only as far as I can figure out one can only assign them to a memo component or a categorized variable in the script.

zifnabbe

thanks for your reply.

http://www.fast-report.com/en/forum/?p=/discussion/9134 wrote:

http://www.fast-report.com/en/forum/?p=/discussion/9134 [/url]
These variables can be referred to like table columns.

Thanks, but I found this thread already, but unfortunately I can't get it right... where is SaldoAtual in this case declared? As a variable in the script? Or as a variable in the report?

technisoft wrote: »

The second kind you use like ordinary Pascal variable. However, they are run-time only as far as I can figure out one can only assign them to a memo component or a categorized variable in the script.

I tried this as well, but I seem to be unable to get it right in case with dates :-(.

Anybody an idea how I can get a date 'variable' formatted into a header?

Something like Memo1.Text := 'Month : '+FormatDateTime('mmmm', Get(<Customers."CUSTOMER_DATE">)

zifnabbe

Ok. It took me some time to figure out what the writer meant in section 6.7 'Using aggregate functions in the script'. But I finally found a way to get this working.

zifnabbe

it might be usefull for others, others can give feedback (or just tell that there is a much more simplistic way).

Put three (in)visible text objects in the footer of the report with the following text:

MIN(<Customer."CONSULT_DATE">,MasterData1)
and
MAX(<Customer."CONSULT_DATE">,MasterData1)
and
[SUM(<Customer."FEE">,MasterData1)]

Than use the following script code:

var
  tmpStr : String;
  ListPeriod, ListTotal : TStringList;
  i : integer;                                
    
procedure GroupFooter1OnBeforePrint(Sender: TfrxComponent);
begin                                                                                          
  tmpStr := '';                                         
  if not Engine.FinalPass then begin
    tmpStr := FormatDateTime('mmmm', MIN(<Customer."CONSULT_DATE">,MasterData1))                     
      + ' - ' + FormatDateTime('mmmm YYYY', MAX(<Customer."CONSULT_DATE">,MasterData1));
    ListPeriod.Add(tmpStr);
    tmpStr := Format('%2.2m', [SUM(<Customer."FEE">,MasterData1)] );
    ListTotal.Add(tmpStr);        
  end;                  
end;

procedure GroupHeader1OnBeforePrint(Sender: TfrxComponent);
begin
  if Engine.FinalPass then begin
    Memo1.Text := 'Period: '+ListPeriod[i];           
    Memo18.Text := 'Total: '+ListTotal[i] + 'bla';        
  end;
  inc(i);                    
end;

procedure OnStartReport(Sender: TfrxComponent);
begin
  ListPeriod := TStringList.Create;
  ListTotal := TStringList.Create;      
end;

procedure OnStopReport(Sender: TfrxComponent);
begin
  ListTotal.Free;                                                   
  ListPeriod.Free;                          
end;

procedure Page1OnBeforePrint(Sender: TfrxComponent);
begin
  i := 0;  
end;

begin

end.

hsm

zifnabbe wrote: »

it might be usefull for others, others can give feedback (or just tell that there is a much more simplistic way).

Thank you. It was very useful for me.
I have three nested groups and need to show an average score (from the detail section) for each group in their respective headers. I cannot use AVG() as not all the detail scores are available so I need to count them, sum then and do the average programatically at the end of each group.
I messed around all day today trying to apply the example in the manual and the demo to my situation and could only get the outer group to behave properly.
I can see that your solution using lists will do the job.
Thanks for posting the solution. Too many people end a thread saying "I've fixed it now" without saying how!
Howard