update sku as s
set 
std_cost_price = t.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) over(partition by s.goods_code)) avg_price
        ,g.std_cost_price std_cost_price
    from
        sku s inner join goods g
        on s.goods_code = g.goods_code
) t
where
    s.goods_code = t.goods_code
and
    t.std_cost_price < t.avg_price
;

select * from sku;