我有两个日期:SQL如何检索两个给定日期之间的中间点?
2012-10-04 12:48:56:000
和2012-10-04 12:48:58:000
预期结果为:
2012-10-04 12:48:57:000
2012-10-04 12:48:56:000
和2012-10-04 12:48:56:010
预期结果为:
2012-10-04 12:48:56:005
(日期是虚构的,因为SQL Server中的毫秒部分DATETIME数据类型由3增加)
我有两个日期:SQL如何检索两个给定日期之间的中间点?
2012-10-04 12:48:56:000
和2012-10-04 12:48:58:000
预期结果为:
2012-10-04 12:48:57:000
2012-10-04 12:48:56:000
和2012-10-04 12:48:56:010
预期结果为:
2012-10-04 12:48:56:005
(日期是虚构的,因为SQL Server中的毫秒部分DATETIME数据类型由3增加)
用自己的日期...
SELECT DATEADD(ms,
DATEDIFF(ms,'2012-10-04 12:48:56:000', '2012-10-04 12:48:58:000')/2,
'2012-10-04 12:48:56:000')
任何人都知道如何在时间(6)值postgresql中做到这一点?我很难过,绝望,并从Sql Server将这个确切的代码移植到Postgres。我觉得这个评论可能是适当的,如果有人发现这一点,并在postgres(标题不说sql服务器,这是我怎么结束在这里)和问题得到解答。 http://stackoverflow.com/questions/34711115/postgresql-to-find-midpoint-between-two-timestamps –
事情是这样的:
with sample_data (start_dt, end_dt) as
(
select cast('2012-10-04 12:48:56:000' as datetime), cast('2012-10-04 12:48:58:000' as datetime)
union all
select cast('2012-10-04 12:48:56:000' as datetime), cast('2012-10-04 12:48:56:010' as datetime)
)
select start_dt, end_dt, dateadd(millisecond, datediff(millisecond, start_dt, end_dt)/2, start_dt)
from sample_data
虽然第二对计算不正确。可能是因为3毫秒的分辨率。
declare @date1 datetime;
declare @date2 datetime;
set @date1 = '2012-10-04 12:48:56:000';
set @date2 = '2012-10-04 12:48:58:000';
select DateAdd(ms, DateDiff(ms, @date1, @date2)/2, @date1)
-- let's day d1 and d2 are DateTime variables (d1 < d2)
-- get the differnce in milliseconds
-- (you can change it but be careful with oveflow situations)
declare @diff integer = datediff (ms, @d1, @d2)
-- the middle is the first date + half of the difference
declare @middle DateTime = dateadd (ms, @diff/2, @d1)
你的意思是你有2日期列,并通过选择要输出的中间点或者是两个日期不同势行? –