Re: possible bug with group by?

Julie Hunt wrote:
> 
> Joseph Shraibman wrote:
> 
> >
> >
> > playpen=> select a, b, case when c is null then 'not set' else 'set' end
> > as z from tablea group by a, b, z;
> > ERROR:  Unable to identify an operator '<' for types 'unknown' and
> > 'unknown'
> >         You will have to retype this query using an explicit cast
> > playpen=>
> 
> Hi,
> 
> should your group by be a, b, c not a, b, z?
> 

That would work for this example.  But shouldn't it work for z also?

I discovered that if I replace z with text I don't get that error, but
then I can't name my columns.