Re: AW: AW: Overloaded UDF

["M. Lazarus" <mlazarus@xxxxxxxx>]

Birgitta,

 In order for this to be accurate, I think that 
something like this might need to be done:

If ( %Parms = -1 Or %Parms >= 3 ) and %Addr(Parm3) <> *NULL;
    //3rd parameter is passed
EndIf;

 The problem is that if there is a call to the 
procedure using 3 parms and then a subsequent 
call using 2 parms, there might be a valid 
pointer in memory at the correct location.  That 
would cause the "%Addr(Parm3) <> *NULL" condition 
to evaluate to true, even though the parm is not 
being passed for this invocation of the procedure.

 Does SQL always pass or clear the pointer to the unused parm?

 -mark


At 12/2/09 01:03 PM, you wrote:
> >>  I believe that should be:
>
> >>If %Parms >= 3 and %Addr(Parm3) <> *NULL;
> >>    //3rd parameter is passed
> >>EndIf;
>
> No, OR is correct, because %PARMS is set to -1 if called from an SQL UDF.
>
>
> Mit freundlichen Grüßen / Best regards
>
> Birgitta Hauser
>
> "Shoot for the moon, even if you miss, you'll land among the stars." (Les
> Brown)
> "If you think education is expensive, try ignorance." (Derek Bok)
> "What is worse than training your staff and losing them? Not training them
> and keeping them!"
>
>
> -----Ursprüngliche Nachricht-----
> Von: midrange-l-bounces@xxxxxxxxxxxx
> [mailto:midrange-l-bounces@xxxxxxxxxxxx] Im Auftrag von M. Lazarus
> Gesendet: Wednesday, 02. December 2009 18:43
> An: Midrange Systems Technical Discussion
> Betreff: Re: AW: Overloaded UDF
>
> Birgitta,
>
>   I believe that should be:
>
> If %Parms >= 3 and %Addr(Parm3) <> *NULL;
>     //3rd parameter is passed
> EndIf;
>
>   as an AND condition instead of and OR condition.
>
>   -mark
>
> At 12/2/09 02:22 AM, you wrote:
> >Hi,
> >
> >Within RPG you need to define the third parameter with Options(*NOPASS:
> >*OMIT).
> >Then you can register 2 functions (one with 2 and the other with 3
> >parameters) with the same SQL Name based on the same RPG function.
> >The overloaded SQL Function will send a *NULL-Pointer for the third not
> >passed parameter.
> >Within your RPG procedure you need to check %PARMS if it is called by RPG
> >with or without optional parameters and check %ADDR(Parm) = *NULL for the
> >third optional parameter if it is called by SQL.
> >
> >For example:
> >If %Parms >= 3 or %Addr(Parm3) <> *NULL;
> >    //3rd parameter is passed
> >EndIf;
> >
> >Mit freundlichen Grüßen / Best regards
> >
> >Birgitta Hauser
> >
> >"Shoot for the moon, even if you miss, you'll land among the stars." (Les
> >Brown)
> >"If you think education is expensive, try ignorance." (Derek Bok)
> >"What is worse than training your staff and losing them? Not training them
> >and keeping them!"
> >
> >-----Ursprüngliche Nachricht-----
> >Von: midrange-l-bounces@xxxxxxxxxxxx
> >[mailto:midrange-l-bounces@xxxxxxxxxxxx] Im Auftrag von sjl
> >Gesendet: Tuesday, 01. December 2009 21:46
> >An: midrange-l@xxxxxxxxxxxx
> >Betreff: Overloaded UDF
> >
> >I have created an SQL UDF using RPG code that accepts two parameters, and I
> >want to add an optional third parameter.
> >
> >As a test, I added an optional third parameter to the sub-procedure in the
> >service program (and created the function again using the same name except
> >with 3 parms), thinking that I could check to see how many parms are being
> >passed to the RPG program by examining the value of %PARMS.  However,
> %PARMS
> >
> >is -1, regardless of the number of parms that I pass via my UDF call
> (either
> >
> >2 or 3).
> >
> >As a Q&D fix, I used a Monitor block when referencing the 3rd parm, but I
> >would like to understand what is really happening under the covers.
> >
> >Code snippet here:  http://code.midrange.com/d072fb0fec.html
> >
> >Regards,
> >sjl