WITH
  tmp_avg AS (
    SELECT
      GOODS_CODE
    , ROUND(AVG(STD_COST_PRICE), 1) AS AVG_STD_COST_PRICE
    FROM
      SKU
      LEFT JOIN SPEC1 USING (SPEC1_CODE)
      LEFT JOIN SPEC2 USING (SPEC2_CODE)
    GROUP BY
      GOODS_CODE
  )
UPDATE SKU
SET
  STD_COST_PRICE = tmp_avg.AVG_STD_COST_PRICE
, UPDATE_USER_NAME = 'MODIFY'
, USER_UPDATE_DATETIME = '2024-08-31 00:00:00'
FROM
  tmp_avg
WHERE
  SKU.GOODS_CODE = tmp_avg.GOODS_CODE
  AND SKU.STD_COST_PRICE < tmp_avg.AVG_STD_COST_PRICE;