The ReadMediaHeader method returns a QueryResults object enumerating the values of a backup media header record.
object.ReadMediaHeader( ) as QueryResults
| Part | Description |
|---|---|
| object | Expression that evaluates to an object in the Applies To list |
A QueryResults object containing zero or one result set defined by these columns.
| Column | Data type | Description |
|---|---|---|
| MediaName | nvarchar(130) | Name of the media. |
| MediaSetId | nvarchar(39) | System-generated unique identifier for the media set. NULL when the media contains only a single media set. |
| FamilyCount | integer | Number of families within the media set. |
| FamilySequence Number |
integer | Ordinal position of the family within the entire media set. |
| MediaFamilyId | nvarchar(39) | System-generated unique identifier for the media family. |
| MediaSequence Number |
integer | Ordinal position of the media within its family. |
| MediaLabelPresent | tinyint | When 1, the MediaDescription column reports the contents of the Microsoft Tape Format label.
When 0, no label is present for the media. The MediaDescription column reports informative text. |
| MediaDescription | nvarchar(256) | Descriptive text. Interpret by using the value returned in the MediaLabelPresent column. |
| SoftwareName | nvarchar(65) | Name of the product creating the media header. |
| SoftwareVendorId | integer | Unique identifier of the manufacturer of the product creating the media header. |
| MediaDate | smalldatetime | Creation date and time of the media header. |
A database backup performed by Microsoft® 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.
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.
HRESULT ReadMediaHeader(
LPSQLDMOQUERYRESULTS* ppResults);
Understanding Media Sets and Families