获取今天午夜的日期和时间并添加到它

Question

是否有一个sql命令可以在午夜获取今天的日期，并且能够为它添加几分钟的时间？

Answer 1

Date now midnight time:

Select DATEADD(d,0,DATEDIFF(d,0,GETDATE()))

ADD 600 Minutes:

Select DATEADD(mi,600,DATEDIFF(d,0,GETDATE()))

Answer 2

Yes, just use datediff and dateadd functions to strip the time from any date, then add a fractional portion of a day to that number

Declare @aDate DateTime
Set @aDate = getDate()
Declare @Minutes Integer
Set @minutes = 600 -- 10 hours

Select DateAdd(day, DateDiff(day, 0, @aDate), 0) + @minutes / 1440.0  -- 1440 min/day
 -- or You could also use the dateadd again...
Select DateAdd(minute, @minutes , DateAdd(day, DateDiff(day, 0, @aDate), 0))

Both selects return 10:00 am on the same day (more or less). This works because of, well, check out this SO answer

EDIT: Added sample script to show how this works:

declare @dtTim datetime = getDate()
declare @today datetime = dateAdd(day, dateDiff(day, 0, @dtTim ), 0)
select  @dtTim, @today

Answer 3

You can also cast to date to strip off the time portion:

declare @minutes int = 600
declare @start datetime = cast(getdate() as date)
declare @finish datetime = dateadd(mi, @minutes, @start)

Although, honestly, I have no idea how it performs compared to

dateadd(day, datediff(day, 0, getdate()), 0)

Answer 4

Use following:

select DATEADD(SECOND, 36000, CAST(CONVERT(VARCHAR(10), GETDATE(), 101) AS datetime))

This way you can adjust the seconds to pinpoint any time of day you want.

Please refer to this for date/time formatting in SQL Server: SQL Server Date/Time Formatting

Answer 5

I had to do something similar, create a procedure to run from a certain time the previous day to a certain time on the current day This is what I did to set the start date to 16:30 on the previous day, basically subtract the parts you don't want to get them back to 0 then add the value that you want it to be.

-- Set Start Date to previous day and set start time to 16:30.00.000

SET @StartDate = GetDate()
SET @StartDate = DateAdd(dd,- 1, @StartDate) 
SET @StartDate = DateAdd(hh,- (DatePart(hh,@StartDate))+16, @StartDate) 
SET @StartDate = DateAdd(mi,- (DatePart(mi,@StartDate))+30, @StartDate) 
SET @StartDate = DateAdd(ss,- (DatePart(ss,@StartDate)), @StartDate) 
SET @StartDate = DateAdd(ms,- (DatePart(ms,@StartDate)), @StartDate) 

Hope this helps someone.