a. Firebird can sometimes convert between data types automatically.
However BIN_AND is overloaded function - it can return either INTERGER or BIGINT depending
on its arguments, so it needs to know the types during statement prepare
(conversion string->number would be done during execution, which is too late in this case)

b. even if it is legal to override internal functions, I do not think it is good idea.

Ivan

-----P?vodni zprava-----
From: Keisuke Kumakura
Sent: Tuesday, October 29, 2013 1:34 AM
To: firebird-support@yahoogroups.com
Subject: [firebird-support] bin_and() in Firebird 2.5.2

Hello,

The SQL statement:
select some from foo where bin_and(bar, '2')<>0;
results in the error:
Arguments for BIN_AND must be integral types or NUMERIC/DECIMAL without
scale
But if we omit single quote around 2(i.e., bin_and(bar, 2)<>0),
the statement is executed fine.

If we declare the following function, the statement is
executed fine irrespective of bin_and(bar, '2') or bin_and(bar, 2).

DECLARE EXTERNAL FUNCTION bin_and
INTEGER, INTEGER
RETURNS INTEGER BY VALUE
ENTRY_POINT 'IB_UDF_bin_and' MODULE_NAME 'ib_udf';

a. Is it illegal to single-quote numeric(e.g., '2') ?
b. Does overriding internal bin_and, bin_or functions pose
any problems for firebird utilities like gbak, nbackup and
others ?

regards,
K. Kumakura




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