ReadBackupHeader Method (SQLServer)
后续版本的 Microsoft SQL Server 将删除该功能。请避免在新的开发工作中使用该功能，并着手修改当前还在使用该功能的应用程序。
The ReadBackupHeader method returns a QueryResults object enumerating the contents of the media maintained by a backup device or operating system file.
语法
object
.ReadBackupHeader(
Restore
)
as
QueryResults
Parts
- object
Expression that evaluates to an object in the Applies To list.
- Restore
Restore object with properties set to specify a backup device or file and, optionally, a backup set.
Prototype (C/C++)
HRESULT ReadBackupHeader(
LPSQLDMORESTORE Restore,
LPSQLDMOQUERYRESULTS* ppResults);
Returns
A QueryResults object containing one result set. For a description of the result set contents, see ReadBackupHeader Method (BackupDevice).
备注
When using the ReadBackupHeader method, one of the Restore object device properties must indicate the device or file maintaining the backup media.
To use the ReadBackupHeader method
Create a SQLServer object.
Connect the SQLServer object to an instance of Microsoft SQL Server on which the source backup device is visible.
Create a Restore object.
Set either the Devices, Files, Pipes, or Tapes property to indicate a device visible on an instance of SQL Server indicated in Step 2 and maintaining the backup media. Specify only a single device or file.
If desired, set the FileNumber property to indicate a specific backup set by ordinal location on the media. By default, the header of the first backup set on the media is enumerated.
Call the ReadBackupHeader method of the SQLServer object using the Restore object created in Step 3 as an argument.
SQL Server can share backup media with other operating system utilities that perform backup of other data, and the media in a device may contain headers created by other utilities.
When the media of a backup device is unused, such as when a disk device is empty, the ReadBackupHeader method succeeds, returning an empty QueryResults object.