psql.edit.6307

ALTER TABLE city ADD COLUMN last_weather_data weather_probe;
UPDATE 
  city c 
SET 
  last_weather = wp 
FROM 
  (
    SELECT 
      wp.city_name,
      wp.created_at,
      rank() OVER created_at_window AS ranking
    FROM
      weather_probe wp
    WINDOW
      created_at_window AS (PARTITION BY city_name ORDER BY created_at DESC)
  ) wpr
    NATURAL JOIN weather_probe wp
WHERE
    wpr.ranking = 1
  AND
    c.name = wp.city_name
RETURNING *
;