create temporary table g as 
select GOODS_CODE, STD_COST_PRICE
from GOODS;

create temporary table t as
select GOODS_CODE,
round(avg(STD_COST_PRICE)) as ave
from SKU
group by GOODS_CODE;

update SKU
set STD_COST_PRICE = g.STD_COST_PRICE,
UPDATE_USER_NAME = 'MODIFY',
USER_UPDATE_DATETIME = '2024-08-31 00:00:00'
from SKU as s
inner join g
on g.GOODS_CODE = s.GOODS_CODE
inner join t
on t.GOODS_CODE = s.GOODS_CODE
and t.ave > s.STD_COST_PRICE;