postgresql unpivot with hstore example

pg_unpivot_ex.sql

WITH fedex_rates_ip
("fid","Type","Weight","ZoneA","ZoneB","ZoneC","ZoneD","ZoneE","ZoneF","ZoneG",
 "ZoneH","ZoneI","ZoneJ","ZoneK","ZoneL","ZoneM","ZoneN","ZoneO","ZonePuertoRico")
as(
  select 
    *
  from (
    values
      (2,'IntlPriority',0,40.25,41.5,43,54.75,116.5,52,51.5,61.25,49.5,63.5,62.5,82,119.25,61,63.25,36.65),
      (3,'IntlPriority',-1,66.25,67.75,62.25,74.25,132,68,68.25,85.75,66.25,84.5,82.25,99.5,136.5,79.75,85.5,null),
      (4,'IntlPriority',-2,70.25,73.5,65.75,77.25,156.25,73,73.25,87.25,73.5,90.5,87.75,129.25,160.75,86,96,null)
  ) as x
)
, fkv AS (
    SELECT 
        f."Type" As type, 
        f."Weight" As weight,
    from fedex_rates_ip AS f
    latteral each(hstore(f) - '{fid,Type,Weight}'::text[]) AS kv 
)

SELECT 
  type, 
  weight, 
  (kv).key AS zone, 
  (kv).value::numeric As price
FROM fkv;

The use of hstore to remove multiple keys will be superseded in Postgresql 10 by operator - (json,text[]) and operator - (jsonb, text[]) that will removed multiple keys at the current top level.