ALTER TABLE public.metadata
	ADD COLUMN rating smallint NOT NULL DEFAULT 0;
ALTER TABLE one_filter_has_many_unit
  ADD COLUMN IF NOT EXISTS id_rating smallint NOT NULL DEFAULT 0;
CREATE OR REPLACE FUNCTION public.update_one_filter_has_many_unit_func ()
  RETURNS trigger
  LANGUAGE plpgsql
  VOLATILE
  CALLED ON NULL INPUT
  SECURITY INVOKER
  COST 1
  AS $$
DECLARE
  one_filter_has_many_unit_table text;
  target_column text;
  filter_type text;
BEGIN
  filter_type = COALESCE(NEW.filter_type, OLD.filter_type);
  IF (filter_type IN (
    'aperture',
    'camera',
    'exposure_time',
    'flash',
    'focal_length',
    'folder',
    'iso',
    'item_type',
    'lens',
    'takentime',
    'rating'
  ))
  THEN
    one_filter_has_many_unit_table = TG_TABLE_SCHEMA || '.one_filter_has_many_unit';
    target_column = 'id_' || filter_type;
    IF (TG_OP = 'INSERT') THEN
      EXECUTE format('INSERT INTO %s (id_unit, %s, id_user) VALUES (%L, %L, %L) ON CONFLICT (id_unit) DO UPDATE SET %s = %L', one_filter_has_many_unit_table, target_column, NEW.id_unit, NEW.id_filter, NEW.id_user, target_column, NEW.id_filter);
    ELSIF (TG_OP = 'DELETE') THEN
      IF (filter_type IN ('rating')) THEN
        EXECUTE format('UPDATE %s SET %s = 0 WHERE id_unit = %L', one_filter_has_many_unit_table, target_column, OLD.id_unit);
      ELSE
        EXECUTE format('UPDATE %s SET %s = NULL WHERE id_unit = %L', one_filter_has_many_unit_table, target_column, OLD.id_unit);
      END IF;
    ELSIF (TG_OP = 'UPDATE') THEN
      EXECUTE format('UPDATE %s SET %s = %L WHERE id_unit = %L AND id_user = %L', one_filter_has_many_unit_table, target_column, NEW.id_filter, NEW.id_unit, NEW.id_user);
    END IF;
  END IF;
  RETURN NULL;
END;
$$;