mysql中一个很容易忽略的起别名的语法

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;