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?
Regards
Julie