SQL DateTime函数使用示例

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

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