Reading decimal filed from Sqlite database
lazarus / 16-Databases

----------------------------------------------------------------------
stone977a · 2010-06-22 00:29

Hi, using Lazarus 0.9.28.2, I created some sample database with simple
table. Connection and selecting data works great.
For connection I user TSqliteConnection with transaction, for query I
use TSQLQuery.
I have no problems except when I write select that selects fields
defined as Decimal(10,5), I get EDatabaseError: error Invalid field
size : 5.

Any ideas?

Regards, Tone

----------------------------------------------------------------------
Lacak2 · 2010-06-22 02:30

This is because DECIMAL fields are created as TBCDFields and in
fields.inc is :

class procedure TBCDField.CheckTypeSize(AValue: Longint);
begin
  If not (AValue in [0..4]) then
    DatabaseErrorfmt(SInvalidFieldSize,[Avalue]);
end;

So ONLY Precision 0..4 is allowed !
(If you change 4 to 5 then error disappears, but only 4 decimal places
will be accepted either)

I am not sure, but I think, that this is bug (or feature request), so
you should report this situation in bug tracker !
(May be that, TFMTBcdField must be implemented to handle correctly
DECIMAL and NUMERIC types with precison > 4)

----------------------------------------------------------------------
stone977a · 2010-06-22 22:27

Thanks, and yes, I think this is bug. After changing type to real it
worked file, so this is my temporary solution.

----------------------------------------------------------------------
Loesje · 2010-06-29 10:55

That's not a bug. Maybe a missing feature if you really want to push
it.

There are no real bcd fields in Free Pascal, only currency-fields,
which have a maximum of 4 decimals.

----------------------------------------------------------------------
Lacak2 · 2010-06-29 22:23

In Delphi6 is:

Code: [Select]class procedure TBCDField.CheckTypeSize(Value: Integer);
begin
--- please don't publish copyrighted code, unless license allows this
---
end;
So it is more tolerant ... may be that, this is also way for FPC ...
at least it will not lead to exception
-or-
Add support for TFMTBcdField ... we have TBcd type (fmtbcd.pp) ... so
IMHO it is not very difficult (as template we can use TBcdField and
modify methods to wrok with TBcd instead of system.currency)

----------------------------------------------------------------------
Lacak2 · 2010-06-30 19:11

Sorry
So can I say, that in Delphi can Value be less than 33 ?
(so not only 1..4, but 1..32)

----------------------------------------------------------------------
bonmario · 2010-06-30 19:34

I'ts already in Mantis: http://bugs.freepascal.org/view.php?id=13652
assigned last year, but without changes ...