Re: ORDER BY col is NULL in UNION causes error?

Bruce Momjian <bruce@momjian.us> writes:
> Updated wording:

>  test=> select * from test union select * from test order by x is null;
>  ERROR:  A UNION/INTERSECT/EXCEPT ORDER BY cannot use expressions or functions, only result column names

This does not meet the style guidelines.

            regards, tom lane