On Fri, Mar 11, 2016 at 4:19 PM, Elein <el...@varlena.com> wrote:
> An unused (yet) enum type cannot display the enum ranges. An empty table
> containing that type cannot display enum ranges.
>
Yes, it can.
CREATE TYPE rainbow AS enum ('red','orange','yellow','blue','purple');
SELECT enum_range(null::rainbow);
enum_range
{red,orange,yellow,blue,purple}
I get the distinction between classes and objects. But in many cases, like
this one, you need to obtain an instance of a class - a null is generally
sufficient - and pass that instance to a function. The function can then
use "pg_typeof(instance_value)::oid" to derive the oid for the
corresponding class. This is a common idiom in PostgreSQL.
The only improvement, besides the error handling point, that I see to be
had here is your understanding of how the system works.
David J.
