2024年6月12日发(作者：)

SELECT DATEADD(year,2147483648, '2006-07-31');

SELECT DATEADD(year,-2147483649, '2006-07-31');

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date Argument

The date argument cannot be incremented to a value outside the range of its data type. In the following statements, the number value that is

added to the date value exceeds the range of the date data type. The following error message is returned: "Adding a value to a 'datetime'

column caused overflow."

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SELECT DATEADD(year,2147483647, '2006-07-31');

SELECT DATEADD(year,-2147483647, '2006-07-31');

Return Values for a smalldatetime date and a second or Fractional Seconds datepart

The seconds part of a smalldatetimevalue is always 00. If date is smalldatetime, the following apply:

If datepart is second and number is between -30 and +29, no addition is performed.

If datepart is second and number is less than-30 or more than +29, addition is performed beginning at one minute.

If datepart is millisecond and number is between -30001 and +29998, no addition is performed.

If datepart is millisecond and number is less than -30001 or more than +29998, addition is performed beginning at one minute.

Remarks

DATEADD can be used in the SELECT , WHERE, HAVING, GROUP BY and ORDER BY clauses.

Fractional Seconds Precision

Addition for a datepart of microsecond or nanosecond for date data types smalldatetime, date, and datetime is not allowed. Milliseconds

have a scale of 3 (.123). microseconds have a scale of 6 (.123456). nanoseconds have a scale of 9 (.123456789). The time, datetime2, and

datetimeoffset data types have a maximum scale of 7 (.1234567). If datepart is nanosecond, number must be 100 before the fractional

seconds of date increase. A number between 1 and 49 is rounded down to 0 and a number from 50 to 99 is rounded up to 100. The

following statements add a datepart of millisecond, microsecond, or nanosecond.

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DECLARE @datetime2 datetime2 = '2007-01-01 13:10:10.1111111'

SELECT '1 millisecond' ,DATEADD(millisecond,1,@datetime2)

UNION ALL

SELECT '2 milliseconds', DATEADD(millisecond,2,@datetime2)

UNION ALL

SELECT '1 microsecond', DATEADD(microsecond,1,@datetime2)

UNION ALL

SELECT '2 microseconds', DATEADD(microsecond,2,@datetime2)

UNION ALL

SELECT '49 nanoseconds', DATEADD(nanosecond,49,@datetime2)

UNION ALL

SELECT '50 nanoseconds', DATEADD(nanosecond,50,@datetime2)

UNION ALL

SELECT '150 nanoseconds', DATEADD(nanosecond,150,@datetime2);

/*

Returns:

1 millisecond 2007-01-01 13:10:10.1121111

2 milliseconds 2007-01-01 13:10:10.1131111

1 microsecond 2007-01-01 13:10:10.1111121

2 microseconds 2007-01-01 13:10:10.1111131

49 nanoseconds 2007-01-01 13:10:10.1111111

50 nanoseconds 2007-01-01 13:10:10.1111112

150 nanoseconds 2007-01-01 13:10:10.1111113

*/

Time Zone Offset

Addition is not allowed for time zone offset.

Examples

A. Incrementing datepart by an interval of 1

Each of the following statements increments datepart by an interval of 1.

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DECLARE @datetime2 datetime2 = '2007-01-01 13:10:10.1111111'

SELECT 'year', DATEADD(year,1,@datetime2)

UNION ALL

SELECT 'quarter',DATEADD(quarter,1,@datetime2)

UNION ALL

SELECT 'month',DATEADD(month,1,@datetime2)

UNION ALL

SELECT 'dayofyear',DATEADD(dayofyear,1,@datetime2)

UNION ALL

SELECT 'day',DATEADD(day,1,@datetime2)

UNION ALL

SELECT 'week',DATEADD(week,1,@datetime2)

UNION ALL

SELECT 'weekday',DATEADD(weekday,1,@datetime2)

UNION ALL

SELECT 'hour',DATEADD(hour,1,@datetime2)

UNION ALL

SELECT 'minute',DATEADD(minute,1,@datetime2)

UNION ALL

SELECT 'second',DATEADD(second,1,@datetime2)

UNION ALL

SELECT 'millisecond',DATEADD(millisecond,1,@datetime2)

UNION ALL

SELECT 'microsecond',DATEADD(microsecond,1,@datetime2)

UNION ALL

SELECT 'nanosecond',DATEADD(nanosecond,1,@datetime2);

/*

Year 2008-01-01 13:10:10.1111111

quarter 2007-04-01 13:10:10.1111111

month 2007-02-01 13:10:10.1111111

dayofyear 2007-01-02 13:10:10.1111111

day 2007-01-02 13:10:10.1111111

week 2007-01-08 13:10:10.1111111

weekday 2007-01-02 13:10:10.1111111

hour 2007-01-01 14:10:10.1111111

minute 2007-01-01 13:11:10.1111111

second 2007-01-01 13:10:11.1111111

millisecond 2007-01-01 13:10:10.1121111

microsecond 2007-01-01 13:10:10.1111121

nanosecond 2007-01-01 13:10:10.1111111

*/

B. Incrementing more than one level of datepart in one statement

Each of the following statements increments datepart by a number large enough to also increment the next higher datepart of date.

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DECLARE @datetime2 datetime2;

SET @datetime2 = '2007-01-01 01:01:01.1111111';

--Statement Result

-------------------------------------------------------------------

SELECT DATEADD(quarter,4,@datetime2); --2008-01-01 01:01:01.110

SELECT DATEADD(month,13,@datetime2); --2008-02-01 01:01:01.110

SELECT DATEADD(dayofyear,365,@datetime2); --2008-01-01 01:01:01.110

SELECT DATEADD(day,365,@datetime2); --2008-01-01 01:01:01.110

SELECT DATEADD(week,5,@datetime2); --2007-02-05 01:01:01.110

SELECT DATEADD(weekday,31,@datetime2); --2007-02-01 01:01:01.110

SELECT DATEADD(hour,23,@datetime2); --2007-01-02 00:01:01.110

SELECT DATEADD(minute,59,@datetime2); --2007-01-01 02:00:01.110

SELECT DATEADD(second,59,@datetime2); --2007-01-01 01:02:00.110

SELECT DATEADD(millisecond,1,@datetime2); --2007-01-01 01:01:01.110

C. Using expressions as arguments for the number and date parameters

The following examples use different types of expressions as arguments for the number and date parameters.

Specifying column as date

The following example adds

2

days to each

OrderDate

to calculate a new

PromisedShipDate

.

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USE AdventureWorks2008R2;

GO

SELECT SalesOrderID

,OrderDate

,DATEADD(day,2,OrderDate) AS PromisedShipDate

FROM rderHeader;

Specifying user-defined variables as number and date

The following example specifies user-defined variables as arguments for number and date.

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DECLARE @days int;

DECLARE @datetime datetime;

SET @days = 365;

SET @datetime = '2000-01-01 01:01:01.111'; /* 2000 was a leap year */

SELECT DATEADD(day, @days, @datetime);

Specifying scalar system function as date

The following example specifies

SYSDATETIME

for date.

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SELECT DATEADD(month, 1, SYSDATETIME());

Specifying scalar subqueries and scalar functions as number and date

The following example uses scalar subqueries and scalar functions,

MAX(ModifiedDate)

, as arguments for number and date.

(SELECT TOP 1

BusinessEntityID FROM )

is an artificial argument for the number parameter to show how to select a number argument from a value

list.

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USE AdventureWorks2008R2;

GO

SELECT DATEADD(month,(SELECT TOP 1 BusinessEntityID FROM ),

(SELECT MAX(ModifiedDate) FROM ));

Specifying constants as number and date

The following example uses numeric and character constants as arguments for number and date.

SELECT DATEADD(minute, 1, '

2007-05-07

09:53:01.0376635');

Specifying numeric expressions and scalar system functions as number and date

The following example uses a numeric expressions (-

(10/2))

, unary operators (

-

), an arithmetic operator (

/

), and scalar system functions

(

SYSDATETIME

) as arguments for number and date.

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SELECT DATEADD(month,-(10/2), SYSDATETIME());

Specifying ranking functions as number

The following example uses a ranking function as arguments for number.

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USE AdventureWorks2008R2;

GO

SELECT ame, me

,DATEADD(day,ROW_NUMBER() OVER (ORDER BY

Code),SYSDATETIME()) AS 'Row Number'

FROM erson AS s

INNER JOIN AS p

ON ssEntityID = ssEntityID

INNER JOIN s AS a

ON sID = ssEntityID

WHERE TerritoryID IS NOT NULL

AND SalesYTD <> 0;

Specifying an aggregate window function as number

The following example uses an aggregate window function as an argument for number.