Sqlserver_ Time Usage

function	Description
GETDATE ()	Returns the current date and time
DATEPART ()	Returns a separate part of the date/time
DATEADD ()	Add or subtract a specified time interval in a date
DATEDIFF ()	Returns a time between two dates
CONVERT ()	Display Date/time in a different format

SQL Date Data type

MySQL stores date or date/time values in the database using the following data types:

• DATE-Format: YYYY-MM-DD
• DATETIME-format: Yyyy-mm-dd HH:MM:SS
• TIMESTAMP-format: Yyyy-mm-dd HH:MM:SS
• Year-format: YYYY or YY

SQL Server uses the following data types to store date or date/time values in the database:

• DATE-Format: YYYY-MM-DD
• DATETIME-format: Yyyy-mm-dd HH:MM:SS
• smalldatetime-format: Yyyy-mm-dd HH:MM:SS
• TIMESTAMP-Format: Unique number

Note: When you create a new table in the database, you need to select a data type for the column!

Definition and usage

1. The DATEPART () function is used to return a separate part of the date/time, such as year, month, day, hour, minute, and so on.

Grammar DATEPART (datepart,date)

The date parameter is a valid day expression. The datepart parameter can be the following value:

2. The DATEADD () function adds or subtracts the specified time interval from the date.

Grammar DATEADD (datepart,number,date)

The date parameter is a valid day expression. The number is the number of intervals you want to add, and for the future time, this is positive, and for the past time, this number is negative.

3. The DATEDIFF () function returns the number of days between two dates.

GrammarDATEDIFF (datepart,startdate,enddate)

The StartDate and EndDate parameters are valid date expressions. The datepart parameter can be the following value:

4. The convert () function is a general function that converts a date to a new data type.

The CONVERT () function can display date/time data in different formats.

Grammar CONVERT ( data_type (length), expression, style)

value	Description
Data_type (length)	Specifies the target data type (with an optional length).
Expression	Specifies the value that needs to be converted.
Style	Specifies the date/time of the output format.

The following table shows the style values that are converted to character data by datetime or smalldatetime:

Value (Century yy)	value (Century yyyy)	Input/Output	Standard
-	0 or 100	Mon dd yyyy hh:miam (or PM)	Default
1	101	Mm/dd/yy	USA
2	102	Yy.mm.dd	Ansi
3	103	Dd/mm/yy	British/french
4	104	Dd.mm.yy	German
5	105	Dd-mm-yy	Italian
6	106	DD Mon yy
7	107	Mon DD, yy
8	108	Hh:mm:ss
-	9 or 109	Mon dd yyyy hh:mi:ss:mmmAM (or PM)	Default+millisec
10	110	Mm-dd-yy	USA
11	111	Yy/mm/dd	Japan
12	112	Yymmdd	Iso
-	113 or	DD Mon yyyy hh:mi:ss:mmm (24h)
14	114	Hh:mi:ss:mmm (24h)
-	120 or	Yyyy-mm-dd Hh:mi:ss (24h)
-	or 121	Yyyy-mm-dd hh:mi:ss.mmm (24h)
-	126	Yyyy-mm-ddthh:mi:ss.mmm (no spaces)	ISO8601
-	130	DD Mon yyyy hh:mi:ss:mmmAM	Hijiri
-	131	Dd/mm/yy Hh:mi:ss:mmmAM	Hijiri

DatePart	Abbreviations
Years	YY, yyyy
Quarter	QQ, Q
Month	MM, M
The day of the year	Dy, y
Day	DD, D
Week	WK, WW
Week	DW, W
Hours	hh
Minutes	MI, n
Seconds	SS, S
Milliseconds	Ms
Subtle	MCs
Na-Sec	Ns

Sqlserver_ Time Usage