Subject Re: Calculated Fields - still didn´t got them
Author Andrei Luís
Nobody?


[]s
Andrei


2012/9/26 Andrei Luís <compuvale.software@...>

> Hello folks,
>
> I'm dealing with a performance problem for a long time, and I know that
> part of it has been the calculated fields I'm using.
>
> I'm doing them by 'my way', and by this I mean 'any way', not the best.
>
> I'm searching about this topic here in the list, and I found something
> like that:
>
> 1 procedure Tdm.qrTestCalculateField(Sender: TIB_Statement; ARow:
> TIB_Row; AField: TIB_Column);
> 2 begin
> 3 if (AField.FieldName='MYCALC1') then
> 4 begin
> 5 AField.AsCurrency := ARow.ByName('FIELD_A').AsCurrency -
> ARow.ByName('FIELD_B').asCurrency;
> 6 end;
> 7
> 8 if (AField.FieldName='MYCALC2') then
> 9 begin
> 10 AField.AsCurrency := ARow.ByName('FIELD_A').AsCurrency +
> ARow.ByName('FIELD_B').asCurrency;
> 11 end;
> 12
> 13 if (AField.FieldName='MYCALC3') then
> 14 begin
> 15 AField.AsCurrency := ARow.ByName('FIELD_A').AsCurrency *
> ARow.ByName('FIELD_B').asCurrency;
> 16 end;
> 17 end;
>
>
> My questions:
> 1 - Is this the best way to use calculated fields in IBO? I mean, is it
> the fastest way thinking about performance?
> 2 - I tried this code, but AField is always NIL!??? So if I run it like
> that, I get an access violation exception at line 3. So I tried to isolate
> this with a 'If AField = nil then exit', but every time the event is
> called, AField is nil, then nothing is calculated.
> 3 - How about the code below? This is what I'm doing today:
> 1 procedure Tdm.qrTestCalculateField(Sender: TIB_Statement; ARow:
> TIB_Row; AField: TIB_Column);
> 2 begin
> 3 ARow.ByName('MYCALC1').asCurrency :=
> ARow.ByName('FIELD_A').AsCurrency - ARow.ByName('FIELD_B').asCurrency;
> 4 ARow.ByName('MYCALC1').asCurrency :=
> ARow.ByName('FIELD_A').AsCurrency + ARow.ByName('FIELD_B').asCurrency;
> 5 ARow.ByName('MYCALC1').asCurrency :=
> ARow.ByName('FIELD_A').AsCurrency * ARow.ByName('FIELD_B').asCurrency;
> 6 end;
>
> []s
> Andrei


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