RE: Triggers or Journals? -- MIDRANGE-L


IBM is going gung ho with triggers for editing on their files.  New files
from IBM have been known to have triggers on them for editing purposes.
Makes sense to me.  When you can maintain a file with utilities, programs,
web, client server, ... why copy the editing routines all over the place?

Rob Berendt

==================
Remember the Cole!


                                                                                
                                         
                    NSmith@lincare.com                                          
                                         
                    Sent by:                   To:     MIDRANGE-L@midrange.com  
                                         
                    owner-midrange-l@mi        cc:                              
                                         
                    drange.com                 Subject:     RE: Triggers or 
Journals?                                    
                                                                                
                                         
                                                                                
                                         
                    03/29/01 09:37 AM                                           
                                         
                    Please respond to                                           
                                         
                    MIDRANGE-L                                                  
                                         
                                                                                
                                         
                                                                                
                                         




Journals just monitor what is going on, whereas triggers can be written to
be an active part of the process.

For example, if you require only uppercase data in a field, and someone
enters lowercase, the trigger could convert it before letting the record
pass.  Or, it could default values into a field when it doesn't like what
is
being written.  Or, if you are using Ref. Constriants, and a record is
written which violates that constraint, the program will get a "hard"
crash.
A trigger could test for the same rules and stop the update and send an
error message to the program which could handle the error a little more
elegantly.  Triggers are also great for "housekeeping" chores, like
timestamping, assigning the next sequential key, etc.

If written properly, the same program being used as a trigger can be called
by a program directly to perform the field editing functions before writing
the actual record,  thereby giving the maintenance program a "heads-up" on
what the trigger is going to find and consolidating all editing in one
place
for consistency.

As far as uses for audit files, I've found them invaluable in researching
problems and for reconstructing point-in-time statuses.

> -----Original Message-----
> From:   Chris Bipes [SMTP:chris.bipes@cross-check.com]
> Sent:   Wednesday, March 28, 2001 11:28 PM
> To:     'midrange-l@midrange.com'
> Subject:     RE: Triggers or Journals?
>
>
> Does any one else have any thing else to add?
>
> Christopher K. Bipes   mailto:ChrisB@Cross-Check.com
> Sr. Programmer/Analyst mailto:Chris_Bipes@Yahoo.com
> CrossCheck, Inc.       http://www.cross-check.com
> 6119 State Farm Drive  Phone: 707 586-0551 x 1102
> Rohnert Park CA  94928 Fax: 707 586-1884
>
>
>
>


************************************************************************************************************************************************************************************************************

This message originates from Lincare Holdings Inc. It contains information
which maybe confidential or privileged and is intended only for the
individual or entity named above.
It is prohibited for anyone else to disclose, copy, distribute or use the
contents of this message.
All personal messages express views solely of the sender, which are not to
be attributed to Lincare Holdings Inc., and may not be copied or
distributed without this disclaimer.
If you received this message in error, please notify us immediately at
MailAdmin@lincare.com or (800) 284-2006.
************************************************************************************************************************************************************************************************************

+---
| This is the Midrange System Mailing List!
| To submit a new message, send your mail to MIDRANGE-L@midrange.com.
| To subscribe to this list send email to MIDRANGE-L-SUB@midrange.com.
| To unsubscribe from this list send email to
MIDRANGE-L-UNSUB@midrange.com.
| Questions should be directed to the list owner/operator:
david@midrange.com
+---



+---
| This is the Midrange System Mailing List!
| To submit a new message, send your mail to MIDRANGE-L@midrange.com.
| To subscribe to this list send email to MIDRANGE-L-SUB@midrange.com.
| To unsubscribe from this list send email to MIDRANGE-L-UNSUB@midrange.com.
| Questions should be directed to the list owner/operator: david@midrange.com
+---