Select aliasses in where and other places of the selectlist?

Hi List,

I know it isn't possible to do queries like:
SELECT 1 AS c, c + 1 AS d;

Other queries that aren't possible are those:
SELECT intfield AS a, intfield * intfield AS square FROM tableX WHERE a
< 10 AND square < 50

Of course, these are bogus examples to simply illustrate my point :)
But is there a good reason not to support it or is it something like
"not yet implemented", "not interesting" or "to complex to (easily)
implement".

Best regards,

Arjen