SELECT

	inventory_single_shop.goods_id,inventory_single_shop.balance,inventory_single_shop.inventory_update_time

FROM

	inventory_single_shop,

	(

		SELECT

			goods_id,

			MAX(inventory_update_time) 'time'

		FROM

			inventory_single_shop

		GROUP BY

			goods_id

	) last_time

WHERE

	inventory_single_shop.goods_id = last_time.goods_id

AND inventory_single_shop.inventory_update_time = last_time.time;

 上面是正确的SQL语句，下面是错误的SQL语句，区别就在于一个给子查询取别名的引号的使用上。

SELECT

	inventory_single_shop.goods_id,inventory_single_shop.balance,inventory_single_shop.inventory_update_time

FROM

	inventory_single_shop,

	(

		SELECT

			goods_id,

			MAX(inventory_update_time) 'time'

		FROM

			inventory_single_shop

		GROUP BY

			goods_id

	) 'last_time'

WHERE

	inventory_single_shop.goods_id = last_time.goods_id

AND inventory_single_shop.inventory_update_time = last_time.time;