Subject Re: [Firebird-Architect] for discussion Transient Data Set
Author Paulo Gaspar
Claudio Valderrama C. wrote:

>Ann W. Harrison wrote:
>
>
>> INSERT INTO <whatever> SELECT <list> FROM <data source> YIELDING
>>...
>>
>>A question is whether the ability to return a transient data set from
>>an update or delete has value, since those operations are not based
>>on a full query expression.
>>
>>
>
>I think the important need is for INSERT, not for deletions and updates,
>unless somebody shows a compelling case.
>
>When RETURNING or YIELDING produce rows, are those rows the ones that are
>stored in the engine? I ask to be sure, since I may want to insert (a,b,c)
>in a row, but pre modify triggers change those values before being stored.
>
>C.
>
>
Well, what you mean by compelling? There are always several ways of
doing something.

Still, I already used "UPDATE...RETURNING..." on Oracle, with some
PL/SQL logic for a ticketing
application as it looked the most convenient (readable, obvious) and
efficient way to do one of the
seat reservation steps.

Regards,
Paulo Gaspar