today和now函数的区别

today和now函数的区别 时间函数YEAR(TODAY())和YEAR(NOW())有什么区别? right now 和just now 的区别 now和nowadays的区别 at once ,right now,right away和now的区别 now and then 和 now and again 的区别? till now 和 until now 用法的区别? up till now和up to now的区别 up to now 和 up till now 的区别 present和now之间的区别是什么? have just和just now的区别 NOW和checking account 的区别?