Subject RE: [Firebird-Architect] XSQLDA/XSQLVAR issues
Author Claudio Valderrama C.
Geoff Worboys wrote:
>
>> Nope. I just don't know anyone seriously interested to
>> implement this. Personally, I wouldn't give it a high
>> priority. BTW, is there anything else than Sybase which
>> supports such a feature? Oracle allows column aliases in
>> the ORDER BY clause only, and considering available ORDER
>> BY <ordinal> this doesn't look as a very nice improvement.
>
> I dont know of any systems that do it, but I still think it
> would be a good idea. I've seen questions about column
> aliases and their lack of relevance in SQL on the IBObjects and other
> lists.

MsSql supports fields aliases. From memory, they can be used in WHERE
clauses and the like, but since SQL by nature has no evaluation order, the
following is invalid:

select f1 as x, x + 1 as x2 ...

The idea is that f1 could be an expression really, so this forces the server
to evaluate in a predefined order, order that it does't guarantee, of
course.

This one of the few features that I like about MsSql, including the ability
to not copy the original blob to the log when it's modified, if you know
what you're doing and are willing to afford the risk of course.

C.