text: CREATE OR REPLACE PROCEDURE price_range_proc(
      INOUT min_price numeric,
      INOUT max_price numeric)
  LANGUAGE 'plpgsql'
  AS $BODY$
  BEGIN
      select min(price), max(price)
      into min_price, max_price
      from products;
  END;
  $BODY$;
  
  COMMENT ON PROCEDURE price_range_proc(numeric, numeric)
      IS 'Gets product price range as min and max values.';
  