SYSDATETIME (Transact-SQL)

Returns a datetime2(7) value that contains the date and time of the computer on which the instance of SQL Server is running.

[!UWAGA]

SYSDATETIME and SYSUTCDATETIME have more fractional seconds precision than GETDATE and GETUTCDATE. SYSDATETIMEOFFSET includes the system time zone offset. SYSDATETIME, SYSUTCDATETIME, and SYSDATETIMEOFFSET can be assigned to a variable of any of the date and time types.

For an overview of all Transact-SQL date and time data types and functions, see Date and Time Data Types and Functions (Transact-SQL).

Transact-SQL Syntax Conventions

Składnia

SYSDATETIME ( )

Return Type

datetime2(7)

Uwagi

Transact-SQL statements can refer to SYSDATETIME anywhere they can refer to a datetime2(7) expression.

SYSDATETIME is a nondeterministic function. Views and expressions that reference this function in a column cannot be indexed.

[!UWAGA]

SQL Server 2012 obtains the date and time values by using the GetSystemTimeAsFileTime() Windows API. The accuracy depends on the computer hardware and version of Windows on which the instance of SQL Server is running. The precision of this API is fixed at 100 nanoseconds. The accuracy can be determined by using the GetSystemTimeAdjustment() Windows API.

Examples

The following examples use the six SQL Server system functions that return current date and time to return the date, time or both. The values are returned in series; therefore, their fractional seconds might be different.

A. Getting the current system date and time

SELECT SYSDATETIME()
    ,SYSDATETIMEOFFSET()
    ,SYSUTCDATETIME()
    ,CURRENT_TIMESTAMP
    ,GETDATE()
    ,GETUTCDATE();
/* Returned:
SYSDATETIME()      2007-04-30 13:10:02.0474381
SYSDATETIMEOFFSET()2007-04-30 13:10:02.0474381 -07:00
SYSUTCDATETIME()   2007-04-30 20:10:02.0474381
CURRENT_TIMESTAMP  2007-04-30 13:10:02.047
GETDATE()          2007-04-30 13:10:02.047
GETUTCDATE()       2007-04-30 20:10:02.047

B. Getting the current system date

SELECT CONVERT (date, SYSDATETIME())
    ,CONVERT (date, SYSDATETIMEOFFSET())
    ,CONVERT (date, SYSUTCDATETIME())
    ,CONVERT (date, CURRENT_TIMESTAMP)
    ,CONVERT (date, GETDATE())
    ,CONVERT (date, GETUTCDATE());

/* All returned 2007-04-30 */

C. Getting the current system time

SELECT CONVERT (time, SYSDATETIME())
    ,CONVERT (time, SYSDATETIMEOFFSET())
    ,CONVERT (time, SYSUTCDATETIME())
    ,CONVERT (time, CURRENT_TIMESTAMP)
    ,CONVERT (time, GETDATE())
    ,CONVERT (time, GETUTCDATE());

/* Returned
SYSDATETIME()      13:18:45.3490361
SYSDATETIMEOFFSET()13:18:45.3490361
SYSUTCDATETIME()   20:18:45.3490361
CURRENT_TIMESTAMP  13:18:45.3470000
GETDATE()          13:18:45.3470000
GETUTCDATE()       20:18:45.3470000
*/

Zobacz także

Odwołanie

CAST and CONVERT (Transact-SQL)

Date and Time Data Types and Functions (Transact-SQL)