WITH AverageCost AS (
    SELECT 
        GOODS_CODE,
        ROUND(AVG(STD_COST_PRICE * 1.0), 1) AS AVG_STD_COST_PRICE
    FROM 
        SKU
    GROUP BY 
        GOODS_CODE
)

UPDATE SKU
SET 
    STD_COST_PRICE = (SELECT g.STD_COST_PRICE FROM GOODS g WHERE g.GOODS_CODE = SKU.GOODS_CODE),
    UPDATE_USER_NAME = 'MODIFY',
    USER_UPDATE_DATETIME = '2024-08-31 00:00:00'
WHERE 
    STD_COST_PRICE < (SELECT AVG_STD_COST_PRICE FROM AverageCost WHERE GOODS_CODE = SKU.GOODS_CODE);