with AVe as (
        select 
            GOODS_CODE,
            ROUND(AVG(coalesce(STD_COST_PRICE,0)),1) as Average
        from SKU
        group by GOODS_CODE
)

,sub as (
    select G.GOODS_CODE,G.STD_COST_PRICE as STD_COST_PRICE
    ,Average
    from SKU as G
    left outer join AVe  
      on G.GOODS_CODE=AVe.GOODS_CODE
    where G.STD_COST_PRICE < AVe.Average
    )

--select *
--from sub

update SKU
set 
    STD_COST_PRICE = sub.STD_COST_PRICE,
    UPDATE_USER_NAME = 'MODIFY',
    USER_UPDATE_DATETIME = '2024-08-31 00:00:00'
from sub
where 
    SKU.GOODS_CODE = sub.GOODS_CODE;

select * from SKU 
where UPDATE_USER_NAME = 'MODIFY'
  and  USER_UPDATE_DATETIME = '2024-08-31 00:00:00'