How to create an “on-the-fly” mapping table within a SELECT statement in Postgresql

Question

I\'m creating a select statement that combines two tables, zone and output, based on a referenced device table and on a mapping of

Answer 1

So just to complement the accepted answer, the following code is a valid, self-contained Postgresql expression which will evaluate to an 'inline' relation with columns (zone_number, output_type_id):

SELECT * FROM 
(VALUES 
  (1, 101), 
  (2, 202), 
  (3, 303), 
  (4, 304)
) as i(zone_number, output_type_id)

(The (VALUES ... AS ...) part alone will not make a valid expression, which is why I added the SELECT * FROM.)