UPDATE SKU
SET
STD_COST_PRICE = SUB.AVG_STD_COST_PRICE
,UPDATE_USER_NAME = 'MODIFY'
,USER_UPDATE_DATETIME = '2024-08-31 00:00:00'

FROM
(
    SELECT
        GOODS.GOODS_CODE
        , MAX(GOODS.STD_COST_PRICE)
        , ROUND(AVG(SK.STD_COST_PRICE)) AS AVG_STD_COST_PRICE
    FROM 
        GOODS
    INNER JOIN SKU AS SK
    ON GOODS.GOODS_CODE = SK.GOODS_CODE

    GROUP BY GOODS.GOODS_CODE
) AS SUB
WHERE
    SUB.GOODS_CODE = SKU.GOODS_CODE 
    -- 副問合せで求めた平均値と比較する。
    AND SKU.STD_COST_PRICE < SUB.AVG_STD_COST_PRICE;