update sku
set
    std_cost_price = goods.std_cost_price
    ,update_user_name = 'MODIFY'
    ,user_update_datetime = '2024-08-31 00:00:00'
from(
    --商品コードごとの標準原価平均算出サブクエリ
    select
        goods_code
        ,round(avg(std_cost_price),0) as std
    from sku
    group by goods_code
) as T
inner join goods
on T.goods_code = goods.goods_code
where sku.goods_code = T.goods_code
and goods.std_cost_price < T.std