Distinct Count in fastreport - delphi

Question

Does anyone know how to make a distinct count in fastreport?
Example
I have the report:
Name sex
João m
João m
Maria f
In the normal count, the result would be 3, but I want one that takes only the number of rows that do not repeat the field name .
In this case, the result would be 2.
Can anyone help me? That's just an example.
I can not do a group by in SQL because I have several fields.

Answer 1

I'm not skilled in using FastReport but I've found this page on the FastReport's official forum.
I think you can change the example by adapting it to your scenario (Note that the syntax could require some adjustments).
Bands:
GroupHeader1 <Sex>
MasterData1 [Name, Sex, ...]
GroupFooter1 [GetDistinctCount]
Script (Only working with dataset sorted by the field to count):
var
LastValue : string;
DistinctCount : integer;
//create this event by double-clicking the event from the Object Inspector
procedure OnGroupHeader1.OnBeforePrint;
begin
if LastValue <> (<Datasetname."Sex">) then
Inc(DinstinctCount);
LastValue := <Datasetname."Sex">
end;
function GetDistinctCount: string;
begin
Result := IntToStr(DistinctCount);
end;
The base idea is that the DistinctCount variable is incremented each time the field value changes.
Script (Should works also with unsorted dataset):
var
FoundValues : array of string;
(* !!IMPORTANT!!
You need to initialize FoundValues array before to start counting: *)
SetLength(FoundValues, 0);
function IndexOf(AArray : array of string; const AValue : string) : integer;
begin
Result := 0;
while(Result < Length(AArray)) do
begin
if(AArray[Result] = AValue) then
Exit;
Inc(Result);
end;
Result := -1;
end;
//create this event by double-clicking the event from the Object Inspector
procedure OnGroupHeader1.OnBeforePrint;
begin
if(IndexOf(FoundValues, <Datasetname."Sex">) = -1) then
begin
SetLength(FoundValues, Length(FoundValues) + 1);
FoundValues[Length(FoundValues) - 1] := <Datasetname."Sex">;
end;
end;
function GetDistinctCount: string;
begin
Result := IntToStr(Length(FoundValues));
end;
The base idea is that each different value found is added to the FoundValues array.

Answer 2

You can do it in Firebird without GROUP BY as:
DECLARE #T TABLE (ID INT IDENTITY (1,1), Name NVARCHAR(25) , Sex CHAR(1));
INSERT INTO #T VALUES
('Sami','M'),
('Sami','M'),
('Maria','F');
SELECT DISTINCT Name , Sex FROM #T
You can also create a View , and then use it in your report.
If you really need to do that in FastReport, you have to use a GroupHeader and a GroupFooter to that.
How ?
You have to write your script in OnBeforePrint event.
procedure OnGroupHeader1.OnBeforePrint;
Create this one by double-clicking in the event in the object inspector.