× The internal search function is temporarily non-functional. The current search engine is no longer viable and we are researching alternatives.
As a stop gap measure, we are using Google's custom search engine service.
If you know of an easy to use, open source, search engine ... please contact support@midrange.com.



Yes we will have to disagree.  Because quoting an 'expert' without giving 
an example of why it would be bad doesn't cut it with me.  (Oh God, am I 
sounding like Joe Pluta now?)  Is she saying that you need to repeat the 
business logic in all possible interfaces to the data?  However, if I send 
an escape message that says that the update failed because of a constraint 
error, and 5250, odbc, and others all have methods of retrieving this 
escape information then why wouldn't that work?

Rob Berendt
-- 
"They that can give up essential liberty to obtain a little temporary 
safety deserve neither liberty nor safety." 
Benjamin Franklin 




Jake Bruster <jakebruster@xxxxxxxxx> 
Sent by: rpg400-l-bounces@xxxxxxxxxxxx
11/17/2003 12:32 PM
Please respond to
RPG programming on the AS400 / iSeries <rpg400-l@xxxxxxxxxxxx>


To
RPG programming on the AS400 / iSeries <rpg400-l@xxxxxxxxxxxx>
cc

Subject
RE: ALL I/O in single module was(ARGH!!! (was file open with LR))






Rob,
 
We'll just have to disagree here. I think she is
speaking of using triggers in general and not just
from a 5250 perspective and makes it quite clear in
the article what her position regarding the proper use
of triggers is. Specifically, she says that ...

"Triggers are ideally suited for implementing business
logic that's independent of the user interface and
directly related to database maintenance functions." 

and 

"[Using triggers for data validation] is contrary to
the essential philosophy of triggers, which assumes
that a trigger may be launched from any application
and that the application writer may not even be aware
that a trigger is associated with a particular
database event."

I think the key phrases in that last sentence is 
"essential philosophy of triggers". Yes, she does
acknowledge that people can and do use triggers for
data validation but she points out that this creates
potential pitfalls and additional work for the
developers and that it goes against her idea of the
intended use of triggers.

Regards,
Jake


--- rob@xxxxxxxxx wrote:

> That's a concern.  The problem is that many writers
> of trigger programs 
> tend to 'ass-u-me' that all executions of the
> trigger are going to come 
> from the same 5250 program they were doing
> maintenance from in the first 
> place.  Thus they tailor it to interact only in that
> environment.  Like 
> certain methods of message handling.  However if you
> do something generic 
> like send an escape message then it will be the job
> of whatever program 
> that did the update to trap for that.  And this
> should be able to occur 
> regardless of your environment:  custom 5250,
> UPDDTA, odbc, JSP's, etc.
> 
> I truly believe that this is what was being
> addressed in the article you 
> quote.
> 
> Rob Berendt

__________________________________
Do you Yahoo!?
Protect your identity with Yahoo! Mail AddressGuard
http://antispam.yahoo.com/whatsnewfree
_______________________________________________
This is the RPG programming on the AS400 / iSeries (RPG400-L) mailing list
To post a message email: RPG400-L@xxxxxxxxxxxx
To subscribe, unsubscribe, or change list options,
visit: http://lists.midrange.com/mailman/listinfo/rpg400-l
or email: RPG400-L-request@xxxxxxxxxxxx
Before posting, please take a moment to review the archives
at http://archive.midrange.com/rpg400-l.



As an Amazon Associate we earn from qualifying purchases.

This thread ...

Replies:

Follow On AppleNews
Return to Archive home page | Return to MIDRANGE.COM home page

This mailing list archive is Copyright 1997-2024 by midrange.com and David Gibbs as a compilation work. Use of the archive is restricted to research of a business or technical nature. Any other uses are prohibited. Full details are available on our policy page. If you have questions about this, please contact [javascript protected email address].

Operating expenses for this site are earned using the Amazon Associate program and Google Adsense.