--- In firebird-support@yahoogroups.com, "lutterot" <lutteroth@...> wrote:

>
> Hello!
>
> I have written a UDF varchar_to_guid which seems to work fine:
>
> /* Gives back the 16 byte GUID for a VARCHAR */
> DECLARE EXTERNAL FUNCTION VARCHAR_TO_GUID
> VARCHAR(32765) BY DESCRIPTOR
> RETURNS CHAR(16) CHARACTER SET OCTETS FREE_IT
> ENTRY_POINT 'udf_varchar_to_guid' MODULE_NAME 'guid_udf';
>
> Now I am using this UDF in a stored procedure CreateStringId:
>
> CREATE PROCEDURE CreateStringId(val VARCHAR(32765))
> RETURNS (id CHAR(16))
> AS BEGIN
> id = varchar_to_guid(:val);
> SUSPEND;
> END^
>
> Now when I am using this procedure like this
>
> select id from CreateStringId('abc')
>
> then I get a different result from using the UDF directly like this
>
> select varchar_to_guid('abc') from SOMETABLE
>
> And when I hard-code the string 'abc' into the store procedure like this
>
> CREATE PROCEDURE CreateStringId(val VARCHAR(32765))
> RETURNS (id CHAR(16))
> AS BEGIN
> id = varchar_to_guid('abc');
> SUSPEND;
> END^
>
> then the result is the correct one (i.e. the same as using the UDF
> directly).
>
> Can anybody help me out and explain this behavior to me?

Does the following query return the same 'wrong' value?
select varchar_to_guid(cast('abc' as varchar(32765)) from SOMETABLE;

Adam