Re: Temporary tables in memory using PL/SQL (as a workaround for not having CREATE TABLE privs)?
Date: Fri, 15 Feb 2008 21:25:30 +0100
> On Feb 14, 2:44 pm, Urs Metzger <u..._at_ursmetzger.de> wrote:
>> Why not just insert the records and delete the old ones afterwards?
> Thanks Urs. Some of the columns in the child tables I need to update
> are part of composite primary keys. In your first example, you update
> a foreign key value.
> For some reason, I thought it wasn't possible to update values that
> were part of a primary key. I didn't think it was allowed. Using
> JavaBeans, I've been told, it isn't allowed. Is it bad practice to
> update values that are part of a primary key? Was it ever not allowed
> in any version of Oracle? Not sure where I got that idea from, but
> your first example works fine.
You can, and IIRC always could, change primary key (doesn't matter if composite or not) and foreign key values if you don't violate constraints. You can
- update a primary key, if it has no children - update a foreign key, if it's new parents are there. That's what I
did in my firts example.
There is yet another way to update primary keys and foreign keys in one transaction: deferrable constraints, which means that integrity will be checked only at commit time. Search the manuals...
Hth Urs Metzger Received on Fri Feb 15 2008 - 14:25:30 CST