"Dave Gurnell" <d(dot)j(dot)gurnell(at)gmail(dot)com> writes:
> Run a query ordered on an expression involving these aliases:
> test=# select x.a as xa, x.b as xb, x.c as xc from numbers as x order by
> (xa + xb + xc);
> ERROR: column "xa" does not exist
> LINE 1: ... x.b as xb, x.c as xc from numbers as x order by (xa + xb +
> ...
> Is this expected behaviour or is it a bug?
It's expected and documented. No, it isn't very consistent :-(.
We're trying to support both the SQL92 and SQL99 approaches to ORDER BY,
and they're not the same.
regards, tom lane