SQL Statement Date Usage and functions

SQL Statement Date Usage and functions

--day (), Month (), year ()--Returns the number of days, months, and years of the specified date;
Select Day (cl_s_time) as ' date ' from class--return days
Select ' Month ' =month (cl_s_time) from class--Return month
Select ' Year ' =year (Cl_s_time) from class--return year

--dateadd (datepart,number,date)--Increase the number of the given date type on the date;
Select DATEADD (yyyy,4,cl_s_time) as ' increased after 4 years ' from class--datepart-year
YY, yyyy
Select DATEADD (q,2,cl_s_time) as ' added after 2 quarter ' from class
--datepart-Quarterly
QQ, Q
Select DATEADD (mm,3,cl_s_time) as ' increased after March ' from class
--datepart-month
MM, M
--datepart-One day of the year
Dy, y
--datepart-Date
DD, D
--datepart-week
WK, WW
--datepart-Hour
hh
--datepart-min
MI, n
--datepart-Sec
SS, S
--datepart-MS
Ms

--datediff (DATEPART,DATE1,DATE2)--Gets the number difference of a given date type between two dates (the entire function result is date2-date1);
Select DateDiff (mm,cl_s_time,cl_o_time) as ' Total Month ' from class



--datepart (Datepart,date)-Returns the value (integer) of the specified date type, based on the given date;
In fact, this is equivalent to day, MONTH, and year functions
Select DATEPART (dd,cl_s_time) as ' date ' from class

--getdate ()--Returns the current date and time. When we design a database, it's often possible to use it as a default value.
Update class set Cl_s_time=getdate () where cl_id=6

SELECT * FROM class


Select CONVERT (varchar), GETDATE (), 0): 2006 10:57am
Select CONVERT (varchar), GETDATE (), 1): 05/16/06
Select CONVERT (varchar), GETDATE (), 2): 06.05.16
Select CONVERT (varchar), GETDATE (), 3): 16/05/06
Select CONVERT (varchar), GETDATE (), 4): 16.05.06
Select CONVERT (varchar), GETDATE (), 5): 16-05-06
Select CONVERT (varchar), GETDATE (), 6): 16 05 06
Select CONVERT (varchar), GETDATE (), 7): 05 16, 06
Select CONVERT (varchar), GETDATE (), 8): 10:57:46
Select CONVERT (varchar), GETDATE (), 9): 2006 10:57:46:827am
Select CONVERT (varchar), GETDATE (), 10): 05-16-06
Select CONVERT (varchar), GETDATE (), 11): 06/05/16
Select CONVERT (varchar), GETDATE (), 12): 060516
Select CONVERT (varchar), GETDATE (), 13): 16 05 2006 10:57:46:937
Select CONVERT (varchar), GETDATE (), 14): 10:57:46:967
Select CONVERT (varchar), GETDATE (), 20): 2006-05-16 10:57:47
Select CONVERT (varchar), GETDATE (), 21): 2006-05-16 10:57:47.157
Select CONVERT (varchar), GETDATE (): 05/16/06 10:57:47 AM
Select CONVERT (varchar), GETDATE (), 23): 2006-05-16
Select CONVERT (varchar), GETDATE (), 24): 10:57:47
Select CONVERT (varchar), GETDATE (), 25): 2006-05-16 10:57:47.250
Select CONVERT (varchar), GETDATE (), (+): 2006 10:57am
Select CONVERT (varchar), GETDATE (), 101): 05/16/2006
Select CONVERT (varchar), GETDATE (), 102): 2006.05.16
Select CONVERT (varchar), GETDATE (), 103): 16/05/2006
Select CONVERT (varchar), GETDATE (), 104): 16.05.2006
Select CONVERT (varchar), GETDATE (), 105): 16-05-2006
Select CONVERT (varchar), GETDATE (), 106): 16 05 2006
Select CONVERT (varchar), GETDATE (), 107): 05 16, 2006
Select CONVERT (varchar), GETDATE (), 108): 10:57:49
Select CONVERT (varchar), GETDATE (), 109): 2006 10:57:49:437am
Select CONVERT (varchar), GETDATE (), 110): 05-16-2006
Select CONVERT (varchar), GETDATE (), 111): 2006/05/16
Select CONVERT (varchar), GETDATE (), 112): 20060516
Select CONVERT (varchar), GETDATE (), 113): 16 05 2006 10:57:49:513
Select CONVERT (varchar), GETDATE (), 114): 10:57:49:547
Select CONVERT (varchar), GETDATE (), 120): 2006-05-16 10:57:49
Select CONVERT (varchar), GETDATE (), 121): 2006-05-16 10:57:49.700
Select CONVERT (varchar), GETDATE (), 126): 2006-05-16t10:57:49.827
Select CONVERT (varchar), GETDATE (), ():???? ?????? 1427 10:57:49:907am
Select CONVERT (varchar), GETDATE (), 131): 18/04/1427 10:57:49:920am

SQL Statement Date Usage and functions