Re: delete cascade
From: paul c <toledobythesea_at_oohay.ac>
Date: Mon, 23 Apr 2007 22:28:00 GMT
Message-ID: <QpaXh.119196$DE1.110798_at_pd7urf2no>
>
>
> That's still a compound delete where someone spells out the delete, or
> are you suggesting that V is a pre-existing view?
>
> If pre-existing, I would think the following more likely:
>
> V = (invoices <AND> items);
> DELETE V where invoice# = 99;
>
> But the above has the problem that only invoices with items will appear
> in the view, which is why I suggested an RVA.
Date: Mon, 23 Apr 2007 22:28:00 GMT
Message-ID: <QpaXh.119196$DE1.110798_at_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 Tue Apr 24 2007 - 00:28:00 CEST