T_sql Date function

　　

The date and time of the date function cardinality expression or the return value from the time interval.

GETDATE (), returns the date and time of the current system. Cases:

SELECT GETDATE (); The result: 2010-05-18 15:53:08.920

DATEPART (Item,date), returns the date specified by the item (Year,month,day,,weekday,hour,minute,secound, etc.), or the corresponding shorthand (year:y), returning the result to an integer. Cases:

SELECT DATEPART (year, ' 2010-05-18 '); The result is: 2010

SELECT DATEPART (MONTH, ' 2010-05-18 '); The result is: 5

SELECT DATEPART (Day, ' 2010-05-18 '); The result is: 18

SELECT DATEPART WEEKDAY, ' 2010-05-18 '); Results: 3 (Tuesday)

SELECT DATEPART (HOUR, ' 2010-05-18 15:59:30 '); The result is: 15

SELECT DATEPART (MINUTE, ' 2010-05-18 15:59:30 '); The result is: 59

SELECT DATEPART (SECOND, ' 2010-05-18 15:59:30 '); The result is: 30

Datename (Item,date), returns the specified item,date of the date as a string. Cases:

SELECT datename (WEEKDAY, ' 2010-05-18 '); Results were: Tuesday

DATEDIFF (ITEM,DATE1,DATE2), calculates the difference between two date parts date1 and Date2, and returns the result of item representing the integer value of the cell. Cases:

SELECT DATEDIFF (year, ' 2000-1-1 ', ' 2010-05-18 '); Result is 10

SELECT DATEDIFF (year, ' 2010-05-18 ', ' 2000-1-1 '); Result is-10

SELECT DATEDIFF (MONTH, ' 2010-01-01 ', ' 2010-05-18 '); Result is 4

SELECT DATEDIFF (Day, ' 2010-05-01 ', ' 2010-05-18 '); Result is 17

DATEADD (i,n,d), the number n in the I-value unit is increased to the specified date d. The result is a datetime type. Cases:

SELECT DATEADD (day,7, ' 2010-05-18 '); The result: 2010-05-25 00:00:00.000

SELECT DATEADD (year,-5, ' 2010-05-18 '); The result: 2005-05-18 00:00:00.000

T_sql Date function