Re: delete cascade

From: Bob Badour <bbadour_at_pei.sympatico.ca>
Date: Mon, 23 Apr 2007 22:13:32 GMT
Message-ID: <gcaXh.27427$PV3.286287@ursa-nb00s0.nbnet.nb.ca>

paul c wrote:

> Bob Badour wrote:
>

>> paul c wrote:

>
> ...
>

>>>> I mention it because it would fully disclose the data to be deleted, 
>>>> which is the invoice and the associated items.
>>>
>>>
>>>
>>> I can see that it would fully enclose, ie., enclose in one relation, 
>>> but not sure how it would disclose any more fully than two selections 
>>> and a join.
>>>
>>> Not trying to be picky but I found your view suggestion to be 
>>> profound and want to make sure I understand this one.
>>
>>
>>
>> I didn't refer to two selects and a join so I find your comment 
>> confusing. I was discussing a single delete that deletes both just as 
>> an "on delete cascade" trigger would delete both.

>
> I had an example like this in mind:
>
> V = (invoices where invoice# = 99) <AND> (items where invoice# = 99);
> DELETE V;
That's still a compound delete where someone spells out the delete, or are you suggesting that V is a pre-existing view?

If pre-existing, I would think the following more likely:

V = (invoices <AND> items);
DELETE V where invoice# = 99;

But the above has the problem that only invoices with items will appear in the view, which is why I suggested an RVA. Received on Mon Apr 23 2007 - 17:13:32 CDT