update SKU
set std_cost_price = t.M_STD_COST_PRICE
    ,update_user_name = 'MODIFY'
    ,user_update_datetime = '2024-08-31 00:00:00'
from (
    SELECT 
        s.GOODS_CODE
        ,ROUND(AVG(s.STD_COST_PRICE), 1) AS AVG_STD_COST_PRICE
        ,g.STD_COST_PRICE as M_STD_COST_PRICE
    FROM 
        SKU s
    INNER JOIN goods g
    on g.goods_code = s.goods_code
    GROUP BY 
        s.GOODS_CODE
        ,g.STD_COST_PRICE) t
where
 t.GOODS_CODE = SKU.GOODS_CODE
and sku.STD_COST_PRICE < t.AVG_STD_COST_PRICE;