RE: referential integrity

["Walden H. Leverich" <WaldenL@xxxxxxxxxxxxxxx>]

>make sure not to delete a header record 
>when there are still detail records 

You mentioned cascading updates later, but I find cascading deleted to
be great. Obviously you have to be careful about their use, it wouldn't
make sense to say "delete all the order lines for item 12345 when I
delete item 12345" But when the children row(s) are truly children I
love cascading delete. 

Take Order Header, Detail, ShipTo. I can allow cascading delete from
order header to detail and shipto and all I have to code in my RPG is
the delete of the header, the OS kills the children. 

The other great advantage of cascading delete is one of later
enhancement. Take the above example again. Say that's in production and
running nicely. Now I want to add a notes function to store user
comments about an order. I can change the relationships to cascade the
delete to the notes table and I don't have to change the program that
deletes an order. That's one less program to check-out, change, test,
check-in, test, and promote.

-Walden

------------
Walden H Leverich III
President & CEO
Tech Software
(516) 627-3800 x11
WaldenL@xxxxxxxxxxxxxxx
http://www.TechSoftInc.com 

Quiquid latine dictum sit altum viditur.
(Whatever is said in Latin seems profound.)