Re: delete cascade

From: paul c <toledobythesea_at_oohay.ac>
Date: Mon, 23 Apr 2007 22:28:00 GMT
Message-ID: <QpaXh.119196$DE1.110798@pd7urf2no>

Bob Badour wrote:
> 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.

Bulls-eye! Thanks, now I get it.

p Received on Mon Apr 23 2007 - 17:28:00 CDT