ReadMediaHeader Method (Restore)
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 ReadMediaHeader method returns a QueryResults object enumerating the values of a backup media header record.
语法
object
.ReadMediaHeader(
Server
)
as
QueryResults
Parts
- object
Expression that evaluates to an object in the Applies To list.
- Server
SQLServer object connected to an instance of Microsoft SQL Server on which the backup device or operating system file is visible.
Prototype (C/C++)
HRESULT ReadMediaHeader(
LPSQLDMOSERVER ServerObject,
LPSQLDMOQUERYRESULTS* ppResults);
Returns
A QueryResults object containing one result set. For a description of the result set contents, see ReadBackupHeader Method (BackupDevice).
备注
A database backup performed by SQL Server can target multiple devices of a single type and can span multiple media maintained by the device. To organize media used in backup, SQL Server defines the media set and media family. A media label, or header record, maintains data about a media's location within a media set and media family.
To use the ReadMediaHeader method
Create a SQLServer object.
Connect the SQLServer object to an instance of 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 or operating system file visible on an instance of SQL Server created in Step 1 and maintaining the backup media.
Call the ReadMediaHeader method of the Restore object using the SQLServer object created in Step 1 as an argument.
When the media of a backup device is unused or unlabeled, such as when a disk device is empty, the ReadMediaHeader method succeeds, returning an empty QueryResults object.