UPDATE sku
SET std_cost_price = avg_table.avg_std_cost_price,
    update_user_name = 'MODIFY',
    user_update_datetime = '2024-08-31 00:00:00'
FROM (SELECT goods_code, ROUND(AVG(std_cost_price)) AS avg_std_cost_price FROM sku GROUP BY goods_code) AS avg_table
WHERE 
  sku.goods_code = avg_table.goods_code AND
  sku.std_cost_price < avg_table.avg_std_cost_price;