UPDATE SKU
SET
 STD_COST_PRICE = SUB.STD_COST_PRICE,
 UPDATE_USER_NAME = 'MODIFY',
 USER_UPDATE_DATETIME = '2024-08-31 00:00:00'

FROM
 (
 SELECT
  SK1.GOODS_CODE,
  GD.STD_COST_PRICE,
  ROUND(AVG(SK1.STD_COST_PRICE)) AS SCP
 FROM
  SKU AS SK1
  INNER JOIN GOODS AS GD
   ON GD.GOODS_CODE = SK1.GOODS_CODE
 GROUP BY
  SK1.GOODS_CODE,
  GD.STD_COST_PRICE
 ) AS SUB
 
WHERE
 SUB.GOODS_CODE = SKU.GOODS_CODE AND
 SKU.STD_COST_PRICE < SUB.SCP;