I am working in an older version of IB that does not have the GEN_UUID() function, so I am working on implementing the function as a UDF, but it is giving me an "arithmetic exception, numeric overflow, or string truncation". I looking at the FB source to see how it is implemented there, but internal functions are implemented in noticeably different ways then an UDF.

Here is what I got:

char* EXPORT fn_GEN_UUID()
{
int size = sizeof(GUID) + 1;
GUID *guidBuff = (GUID*) ib_util_malloc(size);
::ZeroMemory(guidBuff, size);

::CoCreateGuid(guidBuff);

return (char *) guidBuff;
}

/* --------------------------------- */

DECLARE EXTERNAL FUNCTION GEN_UUID
RETURNS CHAR(16) FREE_IT
ENTRY_POINT 'fn_GEN_UUID' MODULE_NAME 'UDF_GEN_UUID';

CREATE DOMAIN UNIQUEIDENTIFIER AS
CHAR(16) CHARACTER SET OCTETS
NOT NULL COLLATE OCTETS;

CREATE TABLE TEST_UUID
(
PKID INTEGER NOT NULL,
UUID_VALUE UNIQUEIDENTIFIER
);

/* --------------------------------- */

INSERT INTO TEST_UUID ( PKID, UUID_VALUE) VALUES ( 1, GEN_UUID());