"Ben Tilly" <btilly@gmail.com> writes:
> ... But then I need this (possibly
> empty) list to have a valid group by statement at the end. In Oracle
> I used to just write it like this:
> SELECT ...
> GROUP BY $possible_term_1
> $possible_term_2
> $possible_term_3
> 'end of possible groupings'
FWIW, that will work if you write it as
'end of possible groupings'::text
I'm disinclined to accept it as-is because (a) it's highly likely to be
a mistake, and (b) there's no principled way to assign a datatype to the
expression, if we are to interpret it as an expression.
Basically anything but an unadorned constant will work there.
regards, tom lane