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.