Hi Dorin

>Yes, exactly.
>You need to test, though, if queries don't become slower (the same occur in VFP when UDFs are used)

Thanks to you I was able to write my first stored procedure in FireBird.

I have just posted this in FireBird Support as I am getting a Function Unknown message

Hi all

I have a stored procedure as below.  The return value of the stored 
procedure I want to use in the SELECT statement of mine.  Currently I have 
tried to utilize it this way and I receive an error stating that the 
"Function Unknown OSACCTDRAMT".  Upper Lower case of the function name does 
not seem to be a problem.

SELECT OSAcctDrAmt(s.bDrAmt, uf.bDr, uf.bCr) AS bBalDr
    FROM tAccountsJV t
       JOIN sAccountsJV s
          ON s.iPID = t.iID
             AND s.iAcctID = 485
       LEFT JOIN uOSAccounts uf
          ON uf.iPID = t.iID
             OR uf.iSID = t.iID ;

The Stored Procedure is as follows;

SET TERM ^ ;

CREATE PROCEDURE OSACCTDRAMT (
     BDRAMT DOUBLE PRECISION,
     BDR DOUBLE PRECISION,
     BCR DOUBLE PRECISION)
RETURNS (
     BOSDRAMT DOUBLE PRECISION)
AS
begin
     bOSDrAmt = CASE WHEN (bDrAmt > 0 AND bCr > 0) THEN bDrAmt - bCr
                     WHEN (bDrAmt > 0 AND bDr > 0) THEN bDrAmt - bDr
                     WHEN (bDr IS NULL AND bCr IS NULL) THEN bDrAmt
                     ELSE 0 END ;

   suspend;
end
^

SET TERM ; ^

GRANT EXECUTE ON PROCEDURE OSACCTDRAMT TO SYSDBA;