Hi, I can help you with win32 or win64 OS.
In pascal language code is this:

function UDF_IsNan(Number:PDouble):integer;cdecl;
begin
if Number=nil then begin result:=0; exit; end;
result:=ord(IsNan(Number^));
end;

(works in Delphi and freepascal).

Declaration in SQL is:

DECLARE EXTERNAL FUNCTION IsNan
DOUBLE PRECISION
RETURNS INTEGER BY VALUE
ENTRY_POINT 'UDF_IsNan' MODULE_NAME 'del_udf';

Note: not tested.

Slavek

Ing. Slavomir Skopalik
Jednatel spolecnosti
Elekt Labs s.r.o.
Chaloupky 158
783 72 Velky Tynec
Czech Republic
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e-mail:skopalik@...
http://www.elektlabs.cz <http://www.elektlabs.cz/>





-----Original Message-----
From: firebird-support@yahoogroups.com
[mailto:firebird-support@yahoogroups.com] On Behalf Of Hernando Duque C
Sent: Friday, August 07, 2009 2:34 PM
To: firebird-support@yahoogroups.com
Subject: [firebird-support] Re: What does mean the NAN value found in some
fields?

>
> Hi, you have to create a UDF function for this and use like this
>
> SELECT ... WHERE IsNan(myfield)>0
>
> or UPDATE WHERE IsNan(myfield)>0

It is a very elegant work arround to it, but I'm just the BD administrator
and I don't know how to do that. I wonder if some one can help me with it.

HDuqueC.







[Non-text portions of this message have been removed]