Re: Extending my question. Was: The relational model and relational algebra - why did SQL become the industry standard?

From: Alfredo Novoa <alfredo_at_ncs.es>
Date: 26 Feb 2003 03:17:24 -0800
Message-ID: <e4330f45.0302260317.31e7008b_at_posting.google.com>


"Mikito Harakiri" <mikharakiri_at_ywho.com> wrote in message news:<3FO6a.7$Ih6.66_at_news.oracle.com>...
> > CREATE TRIGGER phonI INSTEAD OF INSERT ON phonesV
> > REFERENCING NEW_TABLE AS nt
> > FOR EACH ROW MODE DB2SQL
> > BEGIN ATOMIC
> > SELECT v.id, v.number as voice, f.number as fax
> > FROM nt V, nt F
> > WHERE V.id = F.id
> > AND V.phonetype = 'VOICE'
> > AND F.phonetype = 'FAX'
> > EXCEPT SELECT * FROM contacts;
> > END
>
> Simple indeed: just put the inverse view, which is applied to the view
> content increment, into the INSTEAD_OF trigger body.
> ...
> insertion view delta is translated into the base table insert. FOR EACH ROW
> event trigger is adequate. Cool.

Cool, but it is a path to nowhere. Date & McGoveran's approach works perfectly with this example.

Regards,
  Alfredo Received on Wed Feb 26 2003 - 12:17:24 CET

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