RE: SQL date comparison - a better way?

By Jove, I think you've got it!  Especially the last paragraph.

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





qsrvbas@xxxxxxxxxxxx (Tom Liotta)
Sent by: midrange-l-bounces@xxxxxxxxxxxx
08/13/2003 10:34 PM
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        Subject:        RE: SQL date comparison - a better way?


midrange-l-request@xxxxxxxxxxxx wrote:

>   4. RE: SQL date comparison - a better way? (rob)
>
>You're questionable about the new fields needing the maintenance program 
>recompiled.  If I add a field that converts a 6 digit date into a true 
>date field, the maintenance on that could easily be handled with a 
>trigger.  However, in a perfect world, the maintenance program would use 
a 
>true date field and the trigger would convert that into the 6 digit date 
>field for compatibility with the other programs.  Thus getting the right 
>date and not having to use a cut off date.

Rob, I don't see near enough of other techniques for such things, but it 
seems to me that, for most shops, a trigger program that modifies/converts 
values between fields is an example of a maintenance program that ought to 
be recompiled when fields are added to the underlying table. For "most 
shops", that is. Yours may be better.

While buffer offsets to locate the record images are supplied, the actual 
record structure may have changed. I'd want to be certain the new 
structure was brought in. This is not nearly as important in the 
methodology that you advocated where new fields are always added at the 
end, but I'd tend to be cautious anyway.

I also see that you may mean that rather than "re-compiling" an existing 
maintenance program, you can instead extend the file maintenance portion 
of the application by creating, compiling and adding a new trigger. Seems 
reasonable. Part of my appreciation of the whole relational database 
concept is the ability to extend an existing database without disrupting 
current function.

Tom Liotta

-- 
Tom Liotta
The PowerTech Group, Inc.
19426 68th Avenue South
Kent, WA 98032
Phone  253-872-7788 x313
Fax    253-872-7904
http://www.powertechgroup.com


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