Problem solved. It's my mistake that treat the ISC_STATUS type as 32 bits integer. If I make it as 64 bits integer, the problem solved.

--- In firebird-support@yahoogroups.com, "Chee Yang" <cychau@...> wrote:
>
> I am using Firebird 2.5 Embedded in 64 bits windows platform.
>
> I compile my application with Firebird embedded using Delphi XE2 64 bits platform.
>
> I create a table:
>
> CREATE TABLE T_TEST1 (
> DTLKEY INTEGER NOT NULL,
> CURRENCYRATE DECIMAL(14, 6),
> AMOUNT DECIMAL(16, 2),
> SQTY DECIMAL(18, 4),
> PRIMARY KEY(DTLKEY)
> )
>
> Insert a row to table:
>
> INSERT INTO T_TEST1 (DTLKEY, CURRENCYRATE, AMOUNT, SQTY)
> VALUES (1, 9011.2, 1482.8, 1)
>
> I then execute a SQL Query:
>
> SELECT CAST(Amount * CurrencyRate AS DECIMAL(18, 8)) / SQTY FROM T_TEST1
>
> I receive a strange value from the select query.
>
> In 32-bits windows, I will encounter error (this is expected error):
>
> Arithmetic overflow or division by zero has occurred.
> arithmetic exception, numeric overflow, or string truncation.
>