Some useful date processing SQL Snippets
由于项目需要，需要一些个处理日期的sql语句，从网上搜了一下，其中有一篇blog写的不错，共享如下
From this post:
---Calculates the first day of the previous month
SELECT DATEADD(mm, DATEDIFF(m, 0, GETDATE()) - 1, 0)
AS [First day of the previous month]
---Calculates the first day of current month
SELECT DATEADD(mm, DATEDIFF(m, 0, GETDATE()), 0)
AS [First day of the current month]
---Calculates the first day of next month
SELECT DATEADD(mm, DATEDIFF(m, 0, GETDATE()) + 1, 0)
AS [First day of the next month]
---Calculates the last day of the previous month
SELECT DATEADD(d, -1, DATEADD(mm, DATEDIFF(m, 0, GETDATE()), 0))
AS [Last day of the previous month]
---Calculates the last day of the current month
SELECT DATEADD(d, -1, DATEADD(mm, DATEDIFF(m, 0, GETDATE()) + 1, 0))
AS [Last day of the current month]
--Calculates the last day of the next month
SELECT DATEADD(d, -1, DATEADD(mm, DATEDIFF(m, 0, GETDATE()) + 2, 0))
AS [Last day of the next month]
--Calculates the first day of the year
SELECT DATEADD(yy, DATEDIFF(yy,0,GetDate()), 0)
AS [First day of the year]
--Calculates the first day of the quater
SELECT DATEADD(qq, DATEDIFF(qq,0,GetDate()), 0)
AS [First day of the quarter]
--Calculates the first monday of the month
SELECT DATEADD(wk, DATEDIFF(wk,0,dateadd(dd, 6 - DATEPART(Day,GetDate()),GetDate())), 0)
AS [First monday of the month]
--Calculates the last day of the prior month
SELECT DATEADD(mm, DATEDIFF(mm,0,GetDate()), 0)
AS [Last day of the previous month]
--Calculates the last day of the prior year
SELECT DATEADD(yy, DATEDIFF(yy,0,GetDate()), 0)
AS [Last day of the previous year]
--Calculates the last day of the current year
SELECT DATEADD(mm, DATEDIFF(m,0,GetDate() ) + 1, 0)
AS [Last day of the current year]
--Calculates the monday of the current week
SELECT DATEADD(wk, DATEDIFF(wk,0,GetDate()), 0)
AS [Monday of the current week]
--Calculates the yesterdays date
SELECT DATEADD(dd, DATEDIFF(dd,0,getdate()), -1)
AS [Yesterdays date]
--Calculates the todays date
SELECT GetDate()
AS [Todays date]
--Calculates the tommorows date
SELECT DATEADD(dd, DATEDIFF(dd,0,getdate()), 1)
AS [Tommorows date]
---Calculates the 15th day of previous month
SELECT DATEADD(d, 14, DATEADD(mm, DATEDIFF(m, 0, GETDATE()) - 1 , 0))
AS [15th day of previous month]
---Calculates the 15th day of current month
SELECT DATEADD(d, 14, DATEADD(mm, DATEDIFF(m, 0, GETDATE()), 0))
AS [15th day of current month]
---Calculates the 15th day of next month
SELECT DATEADD(d, 14, DATEADD(mm, DATEDIFF(m, 0, GETDATE()) + 1, 0))
AS [15th day of next month]
--Gets the name of the current month
SELECT DATENAME(month, GetDate())
AS [Name of the current month]
--Gets the weekday name of the current date
SELECT DATENAME(dw, GetDate())
AS [Weekday name of the current date]
--Gets the weekday name of the current date next year
SELECT DATENAME(dw, DATEADD(yy, 1, GetDate()))
AS [Weekday name of the current date next year]
--Gets the weekday name of the current date last year
SELECT DATENAME(dw, DATEADD(yy, -1, GetDate()))
AS [Weekday name of the current date last year]
And here's the result for the query above
First day of the previous month
-------------------------------
2008-06-01 00:00:00.000
(1 row(s) affected)
First day of the current month
------------------------------
2008-07-01 00:00:00.000
(1 row(s) affected)
First day of the next month
---------------------------
2008-08-01 00:00:00.000
(1 row(s) affected)
Last day of the previous month
------------------------------
2008-06-30 00:00:00.000
(1 row(s) affected)
Last day of the current month
-----------------------------
2008-07-31 00:00:00.000
(1 row(s) affected)
Last day of the next month
--------------------------
2008-08-31 00:00:00.000
(1 row(s) affected)
First day of the year
-----------------------
2008-01-01 00:00:00.000
(1 row(s) affected)
First day of the quarter
------------------------
2008-07-01 00:00:00.000
(1 row(s) affected)
First monday of the month
-------------------------
2008-07-07 00:00:00.000
(1 row(s) affected)
Last day of the previous month
------------------------------
2008-07-01 00:00:00.000
(1 row(s) affected)
Last day of the previous year
-----------------------------
2008-01-01 00:00:00.000
(1 row(s) affected)
Last day of the current year
----------------------------
2008-08-01 00:00:00.000
(1 row(s) affected)
Monday of the current week
--------------------------
2008-07-21 00:00:00.000
(1 row(s) affected)
Yesterdays date
-----------------------
2008-07-23 00:00:00.000
(1 row(s) affected)
Todays date
-----------------------
2008-07-24 11:40:57.557
(1 row(s) affected)
Tommorows date
-----------------------
2008-07-25 00:00:00.000
(1 row(s) affected)
15th day of previous month
--------------------------
2008-06-15 00:00:00.000
(1 row(s) affected)
15th day of current month
-------------------------
2008-07-15 00:00:00.000
(1 row(s) affected)
15th day of next month
-----------------------
2008-08-15 00:00:00.000
(1 row(s) affected)
Name of the current month
------------------------------
July
(1 row(s) affected)
Weekday name of the current date
--------------------------------
Thursday
(1 row(s) affected)
Weekday name of the current date next year
------------------------------------------
Friday
(1 row(s) affected)
Weekday name of the current date last year
------------------------------------------
Tuesday
(1 row(s) affected)