PB中关于时间和日期的计算函数
PB的时间计算是比较麻烦那，一般只能计算到秒
1、关于如何取得当前日期是星期几
通过函数DayName(today())来获得英文的星期几从而进行需要的操作
2、获得某日期前后几天的日期函数为RelativeDate ( date, n )其中N可以为正负
3、返回多少秒前后的TIME时间：RelativeTime（time,n)其中n 可以为正负
This statement returns 19:01:41:
RelativeTime(19:01:31, 10)
This statement returns 19:01:21:
RelativeTime(19:01:31, - 10)
4、比较两个日期之间相差多少天
前面日期>后面日期的为负值，<的为正值，也就是说日期早的为正，日期晚的为负
This statement returns 4:
DaysAfter(1996-12-20, 1996-12-24)
This statement returns -4:
DaysAfter(1996-12-24, 1996-12-20)
This statement returns 0:
DaysAfter(1996-12-24, 1996-12-24)
This statement returns 5:
DaysAfter(1994-12-29, 1995-01-03)
If you declare date1 and date2 date variables and assign February 16, 1996, to date1 and April
28, 1996, to date2 as follows:
date date1, date2
date1 = 1996-02-16
date2 = 1996-04-28
then each of the following statements returns 71:
DaysAfter(date1, date2)
DaysAfter(1996-02-16, date2)
DaysAfter(date1, 1996-04-28)
DaysAfter(1996-02-16, 1996-04-28)
5、SecondsAfter(time1,time2)等同于DaysAfter():
This statement returns 15:
SecondsAfter(21:15:30, 21:15:45)
This statement returns -15:
SecondsAfter(21:15:45, 21:15:30)
This statement returns 0:
SecondsAfter(21:15:45, 21:15:45)
If you declare start_time and end_time time variables and assign 19:02:16 to start_time and
19:02:28 to end_time as shown below:
time start_time, end_time
start_time = 19:02:16
end_time = 19:02:28
then each of these statements returns 12:
SecondsAfter(start_time, end_time)
SecondsAfter(19:02:16, end_time)
SecondsAfter(start_time, 19:02:28)
SecondsAfter(19:02:16, 19:02:28
答:daysafter()计算天之间的差
--------------------------------------------------------------------------------
答:如果用的sql数据库的话可以用selecttop1datediff()from表名来处理.
--------------------------------------------------------------------------------
答:relativedate：得到指定日期前多少天或后多少天的日期
relativetime：得到指定时间前多少秒或后多少秒的时间
--------------------------------------------------------------------------------
答:relativedate：得到指定日期前多少天或后多少天的日期
relativetime：得到指定时间前多少秒或后多少秒的时间
--------------------------------------------------------------------------------
答:relativedate：得到指定日期前多少天或后多少天的日期
relativetime：得到指定时间前多少秒
或后多少秒的时间
--------------------------------------------------------------------------------
答:pb对时间处理很弱
还是用sql得到你想要的东东吧
--------------------------------------------------------------------------------
答:自己写函数进行时间计算，先把时间转换成字符，去制定位置的字符转换成数字，进行计算，保证不会出错，不要单纯依赖pb中原有的东西。