文章总结了关于DateTime函数用法与数据转换以及简单的参考手册。
在T-SQL中经常会用到与DateTime相关的函数，现将常用函数做一下汇总，以备忘。
们经常出于某种目的需要使用各种各样的日期格式，当然我们可以使用字符串操作来构造各种日期格式,但是有现成的函数为什么不用呢？
SQL Server中文版的默认的日期字段datetime格式是yyyy-mm-dd Thh:mm:ss.mmm
例如:
select getdate()
2004-09-12 11:06:08.177
整理了一下SQL Server里面可能经常会用到的日期格式转换方法:
SQL DAY() – MONTH( ) – YEAR()
DAY('2008-09-30') = 30
MONTH('2008-09-30') = 9
YEAR('2008-09-30') = 2008
SQL DATEPART()
DATEPART(day, '2008-09-30 11:35:00.1234567') = 30
DATEPART(month, '2008-09-30 11:35:00.1234567') =9
DATEPART(year, '2008-09-30 11:35:00.1234567') = 2008
DATEPART(hour, '2008-09-30 11:35:00.1234567') = 11
DATEPART(minute, '2008-09-30 11:35:00.1234567') = 35
DATEPART(second, '2008-09-30 11:35:00.1234567') = 0
DATEPART(quarter, '2008-09-30 11:35:00.1234567') = 3
DATEPART(dayofyear, '2008-09-30 11:35:00.1234567') =273
DATEPART(week, '2008-09-30 11:35:00.1234567') = 40
DATEPART(weekday, '2008-09-30 11:35:00.1234567') =7
DATEPART(millisecond, '2008-09-30 11:35:00.1234567') =123
DATEPART(microsecond, '2008-09-30 11:35:00.1234567') = 123456
DATEPART(nanosecond, '2008-09-30 11:35:00.1234567') = 123456700
DATEPART(tzoffset, '2008-09-30 11:35:00.1234567 -07:00') = -420
SQL DATEADD()
DATEADD(day, 1, '2008-09-30 11:35:00') = 2008-10-30 01:35:00.000
DATEADD(month, 1, '2008-09-30 11:35:00') = 2008-10-30 11:35:00.000
DATEADD(year, 1, '2008-09-30 11:35:00') = 2009-09-30 11:35:00.000
DATEADD(hour, 1, '2008-09-30 11:35:00') = 2008-09-30 12:35:00.000
DATEADD(minute, 1, '2008-09-30 11:35:00') = 2008-09-30 11:36:00.000
DATEADD(second, 1, '2008-09-30 11:35:00') = 2008-09-30 11:35:01.000
DATEADD(quarter, 1, '2008-09-30 11:35:00') =2008-12-30 11:35:00.000
DATEADD(week, 1, '2008-09-30 11:35:00') = 2008-10-07 11:35:00.000
DATEADD(month, -1, '2008-09-30 11:35:00') = 2008-08-30 11:35:00.000
DATEADD(year, 1.5 , '2008-09-30 11:35:00') = 2009-09-30 11:35:00.000
SQL DATENAME()
DATENAME(day, '2008-09-30 11:35:00.1234567') = 30
DATENAME(month, '2008-09-30 11:35:00.1234567') =September
DATENAME(year, '2008-09-30 11:35:00.1234567') = 2008
DATENAME(hour, '2008-09-30 11:35:00.1234567') = 11
DATENAME(minute, '2008-09-30 11:35:00.1234567') = 35
DATENAME(second, '2008-09-30 11:35:00.1234567') = 0
DATENAME(quarter, '2008-09-30 11:35:00.1234567') = 3
DATENAME(dayofyear, '2008-09-30 11:35:00.1234567') =273
DATENAME(week, '2008-09-30 11:35:00.1234567') = 40
DATENAME(weekday, '2008-09-30 11:35:00.1234567') =Saturday
DATENAME(millisecond, '2008-09-30 11:35:00.1234567') =123
DATENAME(microsecond, '2008-09-30 11:35:00.1234567') = 123456
DATENAME(nanosecond, '2008-09-30 11:35:00.1234567') = 123456700
DATENAME(tzoffset, '2008-09-30 11:35:00.1234567 -07:00') = -07:00
SQL DATEDIFF()
DATEDIFF(day, '2007-12-01' , '2008-09-30') = 303
DATEDIFF(month, '2007-12-01' , '2008-09-30') = 9
DATEDIFF(year, '2007-12-01' , '2008-09-30') = 1
DATEDIFF(hour, '06:46:45' , '11:35:00') = 5
DATEDIFF(minute, '06:46:45' , '11:35:00') = 289
DATEDIFF(second, '06:46:45' , '11:35:00') = 17295
DATEDIFF(quarter, '2007-12-01' , '2008-09-30') = 3
DATEDIFF(week, '2007-12-01' , '2008-09-30') = 44
DATEDIFF(hour, '2008-09-30' , '2007-12-01') = -303
SOME OTHER SQL DATE/TIME RELATED FUNCTIONS
GETDATE()
GETUTCDATE()
SYSDATETIME()
SYSUTCDATETIME()
SYSUTCDATETIMEOFFSET()
DATEADD(datepart,NUMBER,date)
DATEADIFF(datepart, startdate,enddate)
TODATETIMEOFFSET(datetime2,tzoffset)
SWITCHOFFSET(datetimeoffset,tzoffest)
ISDATE(expression)
Adding to this - Calculate no of Days between two dates excluding Weekends.
DECLARE @StartDate DATETIME
DECLARE @EndDate DATETIME
SET @StartDate = '2010/05/01'
SET @EndDate = '2010/05/11'
SELECT (DATEDIFF(dd, @StartDate, @EndDate) + 1)-(DATEDIFF(wk, @StartDate, @EndDate) * 2)
-(CASE WHEN DATENAME(dw, @StartDate) = 'Sunday' THEN 1 ELSE 0 END)-(CASE WHEN DATENAME(dw, @EndDate) = 'Saturday' THEN 1 ELSE 0 END) -- 7
| Without century (yy) | With century (yyyy) |
Standard |
Input/Output** |
|---|---|---|---|
| - | 0 or 100 (*) | Default | mon dd yyyy hh:miAM (or PM) |
| 1 | 101 | USA | mm/dd/yy |
| 2 | 102 | ANSI | yy.mm.dd |
| 3 | 103 | British/French | dd/mm/yy |
| 4 | 104 | German | dd.mm.yy |
| 5 | 105 | Italian | dd-mm-yy |
| 6 | 106 | - | dd mon yy |
| 7 | 107 | - | Mon dd, yy |
| 8 | 108 | - | hh:mm:ss |
| - | 9 or 109 (*) | Default + milliseconds | mon dd yyyy hh:mi:ss:mmmAM (or PM) |
| 10 | 110 | USA | mm-dd-yy |
| 11 | 111 | JAPAN | yy/mm/dd |
| 12 | 112 | ISO | yymmdd |
| - | 13 or 113 (*) | Europe default + milliseconds | dd mon yyyy hh:mm:ss:mmm(24h) |
| 14 | 114 | - | hh:mi:ss:mmm(24h) |
| - | 20 or 120 (*) | ODBC canonical | yyyy-mm-dd hh:mi:ss(24h) |
| - | 21 or 121 (*) | ODBC canonical (with milliseconds) | yyyy-mm-dd hh:mi:ss.mmm(24h) |
| - | 126(***) | ISO8601 | yyyy-mm-dd Thh:mm:ss:mmm(no spaces) |
| - | 130* | Kuwaiti | dd mon yyyy hh:mi:ss:mmmAM |
| - | 131* | Kuwaiti | dd/mm/yy hh:mi:ss:mmmAM |
举例如下:
select CONVERT(varchar, getdate(), 120 )
2004-09-12 11:06:08
select replace(replace(replace(CONVERT(varchar, getdate(), 120 ),'-',''),' ',''),':','')
20040912110608
select CONVERT(varchar(12) , getdate(), 111 )
2004/09/12
select CONVERT(varchar(12) , getdate(), 112 )
20040912
select CONVERT(varchar(12) , getdate(), 102 )
2004.09.12
select CONVERT(varchar(12) , getdate(), 101 )
09/12/2004
select CONVERT(varchar(12) , getdate(), 103 )
12/09/2004
select CONVERT(varchar(12) , getdate(), 104 )
12.09.2004
select CONVERT(varchar(12) , getdate(), 105 )
12-09-2004
select CONVERT(varchar(12) , getdate(), 106 )
12 09 2004
select CONVERT(varchar(12) , getdate(), 107 )
09 12, 2004
select CONVERT(varchar(12) , getdate(), 108 )
11:06:08
select CONVERT(varchar(12) , getdate(), 109 )
09 12 2004 1
select CONVERT(varchar(12) , getdate(), 110 )
09-12-2004
select CONVERT(varchar(12) , getdate(), 113 )
12 09 2004 1
select CONVERT(varchar(12) , getdate(), 114 )
11:06:08.177
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