procedure TMainForm.GetCena;
begin
 Cena.Active:=False;
 Cena.SQL.Clear;
 Cena.SQL.Add('select price from Statist where Statist.DateTime<:QDBeg and Statist.Product='+IntToStr(Temp.FieldByName('Product').Value) +' and Statist.Osnovanye=0');
 Cena.ParamByName('QDBeg').AsDateTime:=Temp.FieldByName('DateTime').Value;
 Cena.Active:=True;
 Cena.RecordCount;
 Cena.FindLast;
 Cena1:=Cena.FieldByName('Price').Value;
 Cena.Close;
end;

procedure TMainForm.btnStartClick(Sender: TObject);
begin
DT;
 if DEnd<DBeg then
   begin
     MessageBox(0,'Дата окончания периода меньше даты начала периода !','Неверныё период расчётов',0);
     Exit;
 end;
qOsn.Close;
qOsn.Params[0].AsDateTime:=DBeg;
qOsn.Params[1].AsDateTime:=DEnd;
qOsn.Active:=True;
//********************************
Temp.Active:=False;
Temp.DataBaseName:='STATION32';
Temp.TableName:='Temp';
Temp.TableType:=ttParadox;
Temp.FieldDefs.Clear;
Temp.FieldDefs.Add('DateTime',ftDateTime);
Temp.FieldDefs.Add('Marka',ftString,50,False);
Temp.FieldDefs.Add('Product',ftFloat,0,False);
Temp.FieldDefs.Add('Osnovan',ftString,50,False);
Temp.FieldDefs.Add('Osnovanye',ftFloat,0,False);
Temp.FieldDefs.Add('Litr',ftFloat,0,False);
Temp.FieldDefs.Add('Summa',ftFloat,0,False);
Temp.FieldDefs.Add('Price',ftFloat,0,False);
Temp.FieldDefs.Add('Delta',ftFloat,0,False);
Temp.FieldDefs.Add('Report',ftBoolean,0,False);
Temp.FieldDefs.Add('Discount',ftBoolean,0,False);
Temp.CreateTable;
Temp.Active:=True;
Temp.Edit;
Temp.First;
for n:=1 to qOsn.RecordCount do begin
 Temp.Append;
 Temp.FieldByName('Product').AsString:=qOsn.FieldByName('Product').Value;
 Temp.FieldByName('Osnovanye').AsString:=qOsn.FieldByName('Osnovanye').Value;
 Temp.FieldByName('Discount').AsString:=qOsn.FieldByName('Discount').Value;
 Temp.FieldByName('DateTime').AsDateTime:=qOsn.FieldByName('DateTime').Value;
if qOsn.FieldByName('Discount').Value=True then GetCena
else Cena1:=qOsn.FieldByName('Price').Value;

 Temp.FieldByName('Marka').AsString:=qOsn.FieldByName('Marka').Value;
 Temp.FieldByName('Osnovan').AsString:=qOsn.FieldByName('Name').Value;
 Temp.FieldByName('Litr').AsFloat:=qOsn.FieldByName('LitFact').Value;
 if qOsn.FieldByName('Report').Value=True then Temp.FieldByName('Summa').AsFloat:=qOsn.FieldByName('CurFact').Value
 else if qOsn.FieldByName('Report').Value=False then Temp.FieldByName('Summa').AsFloat:=0;

 Temp.FieldByName('Price').AsFloat:=qOsn.FieldByName('Price').Value;
 s:=(qOsn.FieldByName('LitFact').Value*Cena1)-qOsn.FieldByName('CurFact').Value;
 if s<0.4 then s:=0;
 Temp.FieldByName('Delta').AsVariant:=s;
 Temp.FieldByName('Report').AsBoolean:=qOsn.FieldByName('Report').Value;

 qOsn.Next;
end;

if qOsn.FieldByName('Discount').Value=True then GetCena

s:=(qOsn.FieldByName('LitFact').Value*Cena1)-qOsn.FieldByName('CurFact').Value;

Temp.FieldByName('Price').AsFloat:=qOsn.FieldByName('Price').Value;

//эту операцию выполнить 1 раз перед началом работы
Cena.SQL.Add('select price from Statist where (Osnovanye=0) and (DateTime<:QDBeg) and (Product=:ProdID) ORDER BY DateTime DESC');
Cena.Prepare;

function TMainForm.GetCena(const Date:TDateTime;ProdID:integer;):variant;
begin
Cena.ParamByName('QDBeg').AsDateTime:=Date;
Cena.ParamByName('ProdID').Value:=ProdID;
Query1.Refresh;//непомню сработает или нет...
if not Cena.isEmpty then
 result:=Cena.Fields[0].Value
else
 result:=0;
end;

select s1.Product,s1.price
from Statist s1
where Statist.Osnovanye=0' and Statist.DateTime=
(select max(DateTime) from Statist s2 where s1.Product=s2.Product s2.DateTime<:QDBeg)