Re: Database Trigger Programs

-----Original Message-----
From: William Washington III <w.washington@iols.net>
To: MIDRANGE-L@midrange.com <MIDRANGE-L@midrange.com>
Date: Wednesday, August 09, 2000 1:03 AM
Subject: Database Trigger Programs


>Hi All!
>
>When creating a trigger program (in RPG/ILE) there is a variable length
>section that contains the before and after image of the record that is
>changed.  I know how to access them with the offsets.
>
>My question is:  How is the length of the data structure (for the first
>parameter of the trigger program) calculated?  I always have to make the
>data area ridiculously large, then go into debug mode to see where it ends.
>Is there a way to do this programmatically?  Any thoughts are appreciated.
>

If you declare a data structure that is mapped by the external description
of the file and based on a pointer, then there is no physical allocation of
memory, just a pointer-based map of the data that can be positioned to the
before and/or after image area and used to access the data directly from the
buffers for the trigger without concern over allocating large spaces to read
the data.

Attached is a sample of what I describe...

===========================================================
R. Bruce Hoffman, Jr.
 -- IBM Certified Specialist - AS/400 Administrator
 -- IBM Certified Specialist - RPG IV Developer

"Those who would give up essential Liberty,
  to purchase a little temporary Safety,
  deserve neither Liberty nor Safety."

     - The Papers of Ben Franklin

trigger.rpgle