Hello all.

Is there a way to reuse in the SELECT list columns defined earlier
in it ? With PostgreSQL 8.0, I couldn't manage to do it :

=> CREATE table a (x int);
CREATE TABLE
=> CREATE table b (y int);
CREATE TABLE
=> SELECT x * y AS xy, xy + xy AS twoxy FROM a, b;
ERROR: column "xy" does not exist

--
André Majorel <URL:http://www.teaser.fr/~amajorel/>
Do not use this account for regular correspondence.
See the URL above for contact information.

---------------------------(end of broadcast)---------------------------
TIP 2: Don't 'kill -9' the postmaster

Andre Majorel <aym-lqsgp@teaser.fr> writes:
> Is there a way to reuse in the SELECT list columns defined earlier
> in it ?

No.

You can use multiple levels of select:

select xy, xy + xy from (select x * y as xy from a,b) ss;

but this is not likely to save any computation, just typing.

regards, tom lane

---------------------------(end of broadcast)---------------------------
TIP 2: Don't 'kill -9' the postmaster